The document summarizes a study on the impact behavior of A356 aluminum alloy composites containing 3% albite or 3% SiC particles that were subjected to cyclic thermal fatigue testing between 40-450°C for up to 1000 cycles. Key findings include:
1) The A356 alloy and A356/3% albite composite showed improved impact toughness after 1000 thermal cycles, while the A356/3% SiC composite improved up to 500 cycles and then degraded.
2) Microstructural examination found no cracks after cycling and transformation of acicular silicon particles to a fibrous morphology due to the thermal cycling resembling T6 heat treatment.
3) SEM analysis of the A
Microstructure and Abrasive Wear Properties of Chrome Alloy Steel IDES Editor
En 31 steel is widely used for applications like ball bearings and grinding media balls. The sliding wear properties of En 31 steel has been studied in the past, however the data on abrasive wear properties of En 31 steel is limited. En 31 steel was quenched and tempered at different tempering temperatures. Metallographic and hardness studies were carried out on heat treated samples. The hardened and tempered samples were tested using two body abrasive wear testing apparatus. The abrasive medium used in the present investigation was silicon carbide paper. The effect of normal load and sliding distance on wear loss of as received and heat treated specimens tempered at different tempering temperatures was investigated. The abrasive wear resistance of EN 31 steel with different hardness was compared under different test conditions. The worn out samples were observed by Scanning Electron Microscope to study morphology of worn surfaces. The abrasive wear resistance exhibited an increasing trend with increase in hardness and it was rationalized in terms of microstructure and the hardness.
Study of the Tribological behavior of as cast Al-4.2%Cu-Al2O3 compositeIOSR Journals
The research work is carried out on the study of tribological property of aluminium based metal matrix composite material, which is fabricated by using sol-gel technique. The composite material is prepared through liquid metallurgy method by using varying percentage of Alumina and aluminium and fixed percentage of copper 4.2%. Test sample billet is fabricated through casting method and has been examined the different mechanical behaviour such as Vickers Hardness Number, Ultimate Tensile Strength, 0.2% Proof Stress, etc.
From the study, it has been observed that with increase in the alumina content in matrix the ductility of composite show a contrary effect. The Pin-On-Disc test is used to evaluate the tribological property wear for composite material and it is observered that tendency of wear rate has improved. The weight losses of the specimen are measured and wear and friction characteristics are calculated with respect to time. Depth of wear track, sliding speed, bearing load friction coefficient and wear volume have been shown large sensitivity to the applied normal load and the testing time (or sliding distance). The XRD and SEM analysis are used to analyse the wear debris and track; and silent conclusion has been drawn
EFFECT OF THERMAL EXPOSURE ON THE MECHANICAL AND WEAR PROPERTIES OF AEROSPACE...Journal For Research
Aluminum alloys are becoming increasingly important available data were utilized to prepare maps that are intended to serve to design Al Alloys with desired combination especially in the automotive and aerospace industries aluminum alloys AA6061 T6 is subjected to several combinations of solution treatments to correlate their mechanical tensile properties to hardness and conductivity measurement Additional the AA6061 T6 alloys were thermally exposed to several temperature to simulate heat damage effects the thermal exposure was correlated to the tensile properties and hardness and conductivity measurement however these materials tend to have poor wear resistance during working conditions study was to evaluate the wear behavior of Al alloys with various parameter by using pin-on-disk machine the wear rate was decreased then after database were created to consolidate the information about microstructure mechanical properties and corrosion behavior for Al Alloys.
The document summarizes a study on increasing the salt fog corrosion resistance of plasma nitrided AISI 4340 steel through a pulsed plasma post-oxidation process. Key findings:
1) Post-oxidation treatment produces an oxidized layer on the nitrided surface that fills and seals pores, improving corrosion resistance.
2) Samples post-oxidized for 15 minutes showed the best corrosion performance when exposed to salt fog, with only 1/16 as much red rust as nitrided samples alone.
3) X-ray diffraction analysis found the oxidized layer consisted mainly of magnetite iron oxide, which provides high corrosion resistance.
Aluminum-lithium alloys used in the aerospace industry as structural components
and strengthened by age-hardening. This study aims to improve properties of Al-Li
alloys such as strength, behavior hot rolling and addition element, i.e. Mg and Cu to
this alloy. Several tests were carried out to evaluate the performance of alloy, such as
hardness, tensile, and microstructure by OP, SEM and XRD. Result showed that
addition 3.2% Cu to base alloy improve strength from (62MPa) to (78MPa) when
aging at 175°C.and improve hardness from (97.3 Hv) to (119.79Hv) At the same
temperature. But the improvement is great when addition 0.6% Mg to base alloy
improve tensile strength from (62MPa) to (124MPa) at the same time improved
hardness from (119.79Hv) to (152.96Hv) at the same temperature.
Changes in Structural Features of Al-12Si-3Cu Alloy Due to Age HardeningIRJET Journal
The document discusses changes in the structural features of an Al-12Si-3Cu alloy due to artificial age hardening. Samples of the alloy were solutionized at 500°C for 8 hours and quenched before artificial aging at 200°C for varying times. Hardness measurements and optical microscopy observations were performed. Hardness increased with aging time up to a peak of 145 BHN after 12 hours, corresponding to changes in the morphology and size of eutectic Si particles and dissolution of intermetallic phases. The improvement in hardness was attributed to the formation of coherent precipitates during aging that strengthen the alloy.
A Study on Mechanical and Tribological Properties of Magnesium Alloy AZ31 Rei...ijsrd.com
This document summarizes a study on the mechanical and tribological properties of magnesium alloy AZ31 reinforced with SiC and Al2O3 particulates. Three samples were produced using stir casting: 1) AZ31 alloy, 2) AZ31 with 3% SiC and 1% Al2O3, and 3) AZ31 with 1% SiC and 3% Al2O3. Testing showed that tensile strength, impact strength, and wear resistance were highest for the unreinforced AZ31 alloy. The addition of SiC and Al2O3 particulates decreased these mechanical properties but provided a more homogeneous microstructure.
Microstructure and Abrasive Wear Properties of Chrome Alloy Steel IDES Editor
En 31 steel is widely used for applications like ball bearings and grinding media balls. The sliding wear properties of En 31 steel has been studied in the past, however the data on abrasive wear properties of En 31 steel is limited. En 31 steel was quenched and tempered at different tempering temperatures. Metallographic and hardness studies were carried out on heat treated samples. The hardened and tempered samples were tested using two body abrasive wear testing apparatus. The abrasive medium used in the present investigation was silicon carbide paper. The effect of normal load and sliding distance on wear loss of as received and heat treated specimens tempered at different tempering temperatures was investigated. The abrasive wear resistance of EN 31 steel with different hardness was compared under different test conditions. The worn out samples were observed by Scanning Electron Microscope to study morphology of worn surfaces. The abrasive wear resistance exhibited an increasing trend with increase in hardness and it was rationalized in terms of microstructure and the hardness.
Study of the Tribological behavior of as cast Al-4.2%Cu-Al2O3 compositeIOSR Journals
The research work is carried out on the study of tribological property of aluminium based metal matrix composite material, which is fabricated by using sol-gel technique. The composite material is prepared through liquid metallurgy method by using varying percentage of Alumina and aluminium and fixed percentage of copper 4.2%. Test sample billet is fabricated through casting method and has been examined the different mechanical behaviour such as Vickers Hardness Number, Ultimate Tensile Strength, 0.2% Proof Stress, etc.
From the study, it has been observed that with increase in the alumina content in matrix the ductility of composite show a contrary effect. The Pin-On-Disc test is used to evaluate the tribological property wear for composite material and it is observered that tendency of wear rate has improved. The weight losses of the specimen are measured and wear and friction characteristics are calculated with respect to time. Depth of wear track, sliding speed, bearing load friction coefficient and wear volume have been shown large sensitivity to the applied normal load and the testing time (or sliding distance). The XRD and SEM analysis are used to analyse the wear debris and track; and silent conclusion has been drawn
EFFECT OF THERMAL EXPOSURE ON THE MECHANICAL AND WEAR PROPERTIES OF AEROSPACE...Journal For Research
Aluminum alloys are becoming increasingly important available data were utilized to prepare maps that are intended to serve to design Al Alloys with desired combination especially in the automotive and aerospace industries aluminum alloys AA6061 T6 is subjected to several combinations of solution treatments to correlate their mechanical tensile properties to hardness and conductivity measurement Additional the AA6061 T6 alloys were thermally exposed to several temperature to simulate heat damage effects the thermal exposure was correlated to the tensile properties and hardness and conductivity measurement however these materials tend to have poor wear resistance during working conditions study was to evaluate the wear behavior of Al alloys with various parameter by using pin-on-disk machine the wear rate was decreased then after database were created to consolidate the information about microstructure mechanical properties and corrosion behavior for Al Alloys.
The document summarizes a study on increasing the salt fog corrosion resistance of plasma nitrided AISI 4340 steel through a pulsed plasma post-oxidation process. Key findings:
1) Post-oxidation treatment produces an oxidized layer on the nitrided surface that fills and seals pores, improving corrosion resistance.
2) Samples post-oxidized for 15 minutes showed the best corrosion performance when exposed to salt fog, with only 1/16 as much red rust as nitrided samples alone.
3) X-ray diffraction analysis found the oxidized layer consisted mainly of magnetite iron oxide, which provides high corrosion resistance.
Aluminum-lithium alloys used in the aerospace industry as structural components
and strengthened by age-hardening. This study aims to improve properties of Al-Li
alloys such as strength, behavior hot rolling and addition element, i.e. Mg and Cu to
this alloy. Several tests were carried out to evaluate the performance of alloy, such as
hardness, tensile, and microstructure by OP, SEM and XRD. Result showed that
addition 3.2% Cu to base alloy improve strength from (62MPa) to (78MPa) when
aging at 175°C.and improve hardness from (97.3 Hv) to (119.79Hv) At the same
temperature. But the improvement is great when addition 0.6% Mg to base alloy
improve tensile strength from (62MPa) to (124MPa) at the same time improved
hardness from (119.79Hv) to (152.96Hv) at the same temperature.
Changes in Structural Features of Al-12Si-3Cu Alloy Due to Age HardeningIRJET Journal
The document discusses changes in the structural features of an Al-12Si-3Cu alloy due to artificial age hardening. Samples of the alloy were solutionized at 500°C for 8 hours and quenched before artificial aging at 200°C for varying times. Hardness measurements and optical microscopy observations were performed. Hardness increased with aging time up to a peak of 145 BHN after 12 hours, corresponding to changes in the morphology and size of eutectic Si particles and dissolution of intermetallic phases. The improvement in hardness was attributed to the formation of coherent precipitates during aging that strengthen the alloy.
A Study on Mechanical and Tribological Properties of Magnesium Alloy AZ31 Rei...ijsrd.com
This document summarizes a study on the mechanical and tribological properties of magnesium alloy AZ31 reinforced with SiC and Al2O3 particulates. Three samples were produced using stir casting: 1) AZ31 alloy, 2) AZ31 with 3% SiC and 1% Al2O3, and 3) AZ31 with 1% SiC and 3% Al2O3. Testing showed that tensile strength, impact strength, and wear resistance were highest for the unreinforced AZ31 alloy. The addition of SiC and Al2O3 particulates decreased these mechanical properties but provided a more homogeneous microstructure.
Effect of Step Quenching and Tempering on the Corrosion Behaviour of a Low Ca...inventionjournals
The trust of this research is to critically examine the effect of step quenching and tempering on the corrosion performance of a low carbon steel in 0.1M HCl aqueous solution. The steel was first normalized at 850OC for 1 hour. This was followed by step quenching heat treatment, which involved austenitizing at 850OC followed by slow cooling in the furnace to and soaking at various temperatures in the (α + γ) region of 730OC, 750OC and 770OC for 30 minutes and then quenched in water. Some set of the samples were tempered for 1 hour at 320OC and air cooled. Samples were prepared for microscopic examination and corrosion performance evaluation from all the heat treatment procedures. The weight loss method was used to evaluate the corrosion rate. Volume fraction of martensite was measured for the as-quenched step quenched samples. From the results, it was observed that martensite volume fraction increased with increase in soaking temperature. The results also revealed that step quenching increases the susceptibility of the investigated steel to corrosion, while tempering the as-quenched step quenched steel reduces corrosion susceptibility. Hence, it was recommended that for applications of this material in chloride environment, tempering should always proceed step quenching.
Optimization of spheroidized annealing process parameters on AISI 10B21 steel...Steffi Wang
This document analyzes the optimization of spheroidized annealing process parameters on AISI 10B21 steel wire using the Taguchi approach. It aims to improve the mechanical properties of steel wires for cold forming of screws. Three annealing parameters - temperature, heating time, and cooling temperature - were tested at different levels using an orthogonal array experiment. Results found that annealing temperature was the most significant factor affecting tensile strength and ductility. The optimum conditions were determined to be 725°C temperature, 7 hours heating time, and 500°C cooling temperature to achieve a tensile strength of 40.94 kgf/mm2 and ductility of 26.03% while minimizing hardness. This provides a reference for wire manufacturers to improve
Experimental Investigation on Mechanical Properties of Hybrid Metal Matrix Co...IJMERJOURNAL
The document describes an experimental investigation into the mechanical properties of hybrid metal matrix composites reinforced with alumina, graphite, and silicon carbide. Aluminum 6063 alloy was used as the matrix material. Composites with varying compositions of the reinforcements were fabricated via stir casting. Testing showed that hardness and tensile strength increased with the addition of reinforcements. In particular, a composite with 5% silicon carbide, 5% alumina, and 5% graphite exhibited the highest hardness of 49.6 HBW and tensile strength of 133 MPa, representing an improvement over the matrix material alone.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
This summary provides the key information from the document in 3 sentences:
The document discusses a study on the austempering behavior of engineering grade ductile iron castings. Various factors were examined including heat treatment parameters, chemical composition, and nodular characteristics. The results showed that austempering temperature and time had the greatest effect on impact toughness, while higher austempering rates were achieved with additions of nickel, molybdenum, and copper to the alloy composition.
Effects of thermo mechanical simulation on the corrosion of steelJaideep Adusumelli
Performed numerous stress-strain elasticity tests along with impact test under controlled temperature and stress factors.
then the corrosion properties were studied based on the microstructures and corrosion current graphs.
The document summarizes research on aluminum 7075 alloy composites reinforced with alumina nanoparticles. Microstructural analysis found that 1.0 wt% alumina nanoparticles provided the optimal properties. Specifically:
- 1.0 wt% alumina composites exhibited maximum hardness of 134 HV and lowest wear rate. Higher amounts resulted in decreased hardness and increased wear.
- SEM images showed alumina nanoparticles were well dispersed through the aluminum matrix. Some agglomeration was observed at higher nanoparticle fractions.
- XRD analysis confirmed the presence of aluminum and alumina phases. Peak broadening and shifts indicated refinement of aluminum grains with increased nanoparticles.
- AFM images showed increased surface roughness with higher nanoparticle content
Effects of cryogenic treatment on tool steel aisi d6eSAT Journals
1. The document discusses the effects of cryogenic treatment on tool steel AISI-D6. Cryogenic treatment involves cooling tool steel to below atmospheric temperatures (around -1960°C or -3100°F) using liquid nitrogen.
2. Cryogenic treatment was found to improve the mechanical properties of AISI-D6 steel, including increased hardness, wear resistance, and toughness compared to untreated steel. This is due to the transformation of austenite crystal structure to martensite during cryogenic treatment.
3. Experiments showed that cryogenically treated AISI-D6 specimens exhibited higher hardness, lower wear rates, and increased toughness compared to conventionally heat treated specimens.
IJERD(www.ijerd.com)International Journal of Engineering Research and Develop...IJERD Editor
This document summarizes a study on the effect of heat treatment on the microstructure and mechanical properties of medium carbon steel. Two grades of steel were tested, one with copper and one without. Samples underwent various heat treatments including annealing, normalizing, quenching, and tempering at different temperatures. Hardness, ultimate tensile strength, and ductility were then measured. Results showed that steel with copper had higher hardness and strength but lower ductility. Hardness and strength decreased with increasing tempering temperature, while ductility increased. The study provides data on the mechanical properties and microstructure of heat treated medium carbon steel.
Influence of Heat Treatment on Mechanical Properties of Aisi1040 SteelIOSR Journals
This investigation is concerned to evaluate the influence of heat treatment on mechanical behavior of AISI1040 steel; it is one of the grades of medium carbon steel of American standard containing 0.40% carbon in its composition. Specimen of quenched/hardened AISI1040 steel was tempered at temperature (650,450&250℃) for 60, 90&120 minutes to modify desired properties. The mechanical behavior, particularly, ultimate tensile strength, yield strength and elongation were investigated using universal testing machine; while the hardness measurement was done on Rockwell hardness testing machine of heat treated specimens. Result shows that the ultimate tensile strength and the yield strength decrease while the elongation increases with an increase in tempering temperature and tempering time of different tempered specimen. The hardness of quenched/hardened specimen decreases with an increase in tempering temperature and tempering time. Furthermore, increasing temperature and lowering time produces approximately same result as decreasing temperature and increasing time.
This document summarizes a study on the effect of quenching media, heat treatment, and alloying elements on the properties of Al-Si-Mg alloys. The study prepared Al-Si-Mg alloys and studied how quenching in polymer solution or water, heat treatment, and adding alloying elements like B and Ti impacted properties like microhardness. Results showed that adding 0.15% B with 1% Ti improved microhardness by 57% compared to the base alloy. Quenching in polymer solution also improved thermal stability during aging at 175°C compared to water quenching. Mechanical properties were measured using ultrasound techniques and microstructure was examined using optical microscopy.
An equiaxed, submicron grain size distribution was generated in an Al (0.1 wt.% Sc) alloy by
processing through equal channel angular pressing followed by a low temperature pre-
ageing heat treatment. The alloy was subsequently annealed for various times at 300, 350,
400 and 450° C for investigating the thermal stability of the deformation microstructure. It
was found that up to 400° C, the submicron grain structure coarsens slowly and uniformly by
a process of continuous recrystallization.
Generally the prediction of behaviour of material at high temperature is very difficult. During design of
components which are subjected to or working at high temperature must consider the testing at elevated
temperature. Hot tensile testing (HTT) is the method of tensile testing of material at elevated temperature. The
materials used for automotive or aerospace applications are mostly subject to cyclic loading, high temperature
and sometimes involve high frequency vibrations. High strength aluminium alloys are one class of materials that
are widely used in the automotive and aerospace industries .In this work I test A413 material for HTT at different
temperature and strain rate, which can be used for piston.
Keywords — HTT, high temperature, strain rate, piston, automotive or aerospace.
Effect of cryogenic treatment on tool steel (aisi ¬d2)eSAT Journals
Abstract
In present scenario modernization of machine tools is on prime consideration that is an optimization of desired properties in machine tool parts means alternation of properties for that previously we employed heat treatment of steel, thus we have some improved properties but does not achieved correct solution for the problem. In modern age a new technology is comes on the front line, recognize by Acronyms C.T.P. or Cryogenic treatment of steel which has been done in cooling Atmosphere below Atmospheric tem. About – 1960C or- 3100F. During this temp. Range conversion of Austenite to marten site takes place. Thus we have got increased some desirable properties like reduced wear & Tear. Increased Hardness Micro- structure improved, Stress relieving properties also improved. In this paper tool Steel AISI- D2 is used for cryogenic treatment & study is performed regarding Micro- structure and Hardness, after Cryogenic treatment comparison is also made with un-treated test specimen.
Keywords:-AISI- D2, Cryogenic Treatment, Phase Transformation, Hardness, Micro- Structure
Effect of Quenching Media on Mechanical Properties for Medium Carbon SteelIJERA Editor
In this research work the mechanical properties of medium carbon steel has been studied . the Steel AISI 1039
quenched in different quenching media. These quenching media were cold water, water , oil and hot water.
Hardness , tensile , impact and wear tests have been carried out for specimens after quenching in different
media.
It was found that the tensile strength and hardness increased with increasing the heating temperature values of
heat treatment process. Also quenching in cold water has a great effect on tensile strength and hardness values .
where the heights value for tensile strength was (998.6N/mm²) and the hardness was (360.4 Hv) for steel which
quenching in cold water. The percentage of elongation decreased with increasing the temperature of heat
treatment process. also the lowest values of elongation was after quenching process in cold water.
However, the impact toughness and wear rate values were high for alloy after stress relief and lower after
quenching in different media. But the lowest values were recorded after quenching in cold water. It was found
that the absorbed energy and the wear rate for the alloy quenched in cold water were (23.6) J and
(2x10¯⁷gm/cm) respectively. While, for steels treated with the stress relief process were (62.02) J and
(7x10¯⁷gm/cm) respectively.
This document summarizes a study on the effects of yttrium on the mechanical properties and chemical stability of the passive film on an aluminide coating applied to 1045 steel. Samples were prepared with and without the addition of yttrium. Nanoindentation tests found that the yttrium-containing coating had greater hardness and elasticity than the yttrium-free coating. Scratch tests also showed that the passive film on the yttrium coating had a higher critical load, indicating greater resistance to failure. Electron work function measurements demonstrated that the passive film on the yttrium coating was more chemically stable. The addition of yttrium improved both the mechanical properties and chemical stability of the passive film, enhancing corrosion and
Some Results from the Investigation of Effects of Heat Treatment on Propertie...IJERDJOURNAL
Abstract:- The results of an investigation which was undertaken to reveal the differences in the mechanical properties and microstructural characteristics of two types of Ni-hard cast irons are presented in this study. The cast irons were obtained in a laboratory conditions and their compositions are in accordance with European standard EN 12513. One type of cast iron is EN GJN-HV520 (Ni-hard 2) containing 2.10% Cr and the second type EN GJN-HV600 (Ni-hard 4) with 9.04% Cr. The cast irons were evaluated in both as-cast and heat treated conditions. To improve mechanical properties specifically wear resistance, the samples of both types Ni-hard cast irons were subjected to different heat treatment processes. Annealing of Ni-hard 2 samples at 480°C during 4 hours caused increasing of hardness for about 13.5% due to additional precipitation of secondary carbides. On the other hand the heat treatment process consisting of annealing at 790°C during 4-8 hours of Ni-hard 4 samples, compared to the as-cast condition, improve the hardness for about 22.5%. In this case besides precipitation of secondary carbides, transformation of retained austenite to martensite occurs.
Welding Studies on WB36 for Feed Water Pipingijceronline
To increase efficiency, reduce emissions, cost and to reduce weight of boiler per MW, the power manufacturing sectors are going towards the once through technology (super critical boiler) instead of sub- critical. Once through supercritical (OTSC) technology has become a focal point for effective utilization of coal-based thermal power generation sector in India. Another main advantage of moving towards OTSC technology is reducing the weight of the boiler per MW, which can be done by going for material capable of handling higher pressure and temperature than the conventional material. So, in order to keep pace with these technologies, research on newer materials for every boilers line, which can operate at both higher pressure and temperature, has been initiated. So, in this article, we have taken one such feed water system and headers, where WB 36 steel (15 MiCuMoNiNb5) can be used instead conventional standard carbon steel like A106 grade B or C, which are usually used. For super critical, ultra super critical power plants this conventional materials like A106 grade B or C, leads to very thick piping system. V&M has developed WB 36 steel (15 MiCuMoNiNb5) for high pressure piping of boiler feed water system. This heat-resistant, copperalloyed ferritic steel 15MiCuMoNiNb5 has been widely used in European nuclear and conventional power plants for decades for feed water system. This widespread application is due to the toughness and strength, caused by the precipitation of copper, that are exhibited even at elevated temperatures which other fine-grained structural steels have at room temperature. The aim of this project “Welding Studies on WB36 Steel for Feed Water Piping” was taken to understand the metallurgy and the behavior of the new materials under different manufacturing operations.
SIMONA CAVALU_IDENTIFICATION OF THE URINARY STONE COMPOSITION UPON EXTRACORPO...Simona Cavalu
Abstract. The study was carried out to investigate the composition and type of different urinary
stones upon application of extracorporeal shock wave lithotripsy. ATR FTIR spectra revealed the
marker bands of a mixed stone composition containing calcium oxalate monohydrate/ calcium
carbonate, respectively calcium oxalate monohydrate/cystine. The surface morphology of the samples
and elemental analysis was performed by SEM-EDAX confirming the presence of oxalate, carbonate
and cystine in the samples. Combination of FTIR spectroscopy and SEM-EDAX allowed quantitative
and qualitative evaluation of components, the spatial distribution and the percent of major and trace
elements present in a single sample.
Stone disease evaluation in Pathology laboratory: Current prospective.Sanjeev Mehta
This document discusses metabolic evaluation and stone analysis for kidney stones. It explains that stone analysis identifies the stone composition and underlying causes, which helps determine the appropriate treatment plan. A variety of tests are used, including blood and urine tests, 24-hour urine collection to measure supersaturation levels, and analyzing the stone composition. Integrating the results of these analyses can identify metabolic abnormalities and other factors in 90-95% of cases, guiding personalized medical management and prevention of future stone recurrences.
1. Near Net Shape technologies like thixomolding and rheocasting allow for shaping metals in a semi-solid state, producing parts with tight tolerances and reduced machining compared to conventional casting.
2. Thixomolding involves reheating alloy pellets into the semi-solid state and injecting into a mold, while rheocasting uses a machine to slowly fill a mold with semi-solid metal slurry.
3. Both technologies are being applied industrially, with thixomolding common for magnesium parts and rheocasting still at a pre-industrial stage for aluminum. Examples are given of thixomolded magnesium components for applications like
Effect of Step Quenching and Tempering on the Corrosion Behaviour of a Low Ca...inventionjournals
The trust of this research is to critically examine the effect of step quenching and tempering on the corrosion performance of a low carbon steel in 0.1M HCl aqueous solution. The steel was first normalized at 850OC for 1 hour. This was followed by step quenching heat treatment, which involved austenitizing at 850OC followed by slow cooling in the furnace to and soaking at various temperatures in the (α + γ) region of 730OC, 750OC and 770OC for 30 minutes and then quenched in water. Some set of the samples were tempered for 1 hour at 320OC and air cooled. Samples were prepared for microscopic examination and corrosion performance evaluation from all the heat treatment procedures. The weight loss method was used to evaluate the corrosion rate. Volume fraction of martensite was measured for the as-quenched step quenched samples. From the results, it was observed that martensite volume fraction increased with increase in soaking temperature. The results also revealed that step quenching increases the susceptibility of the investigated steel to corrosion, while tempering the as-quenched step quenched steel reduces corrosion susceptibility. Hence, it was recommended that for applications of this material in chloride environment, tempering should always proceed step quenching.
Optimization of spheroidized annealing process parameters on AISI 10B21 steel...Steffi Wang
This document analyzes the optimization of spheroidized annealing process parameters on AISI 10B21 steel wire using the Taguchi approach. It aims to improve the mechanical properties of steel wires for cold forming of screws. Three annealing parameters - temperature, heating time, and cooling temperature - were tested at different levels using an orthogonal array experiment. Results found that annealing temperature was the most significant factor affecting tensile strength and ductility. The optimum conditions were determined to be 725°C temperature, 7 hours heating time, and 500°C cooling temperature to achieve a tensile strength of 40.94 kgf/mm2 and ductility of 26.03% while minimizing hardness. This provides a reference for wire manufacturers to improve
Experimental Investigation on Mechanical Properties of Hybrid Metal Matrix Co...IJMERJOURNAL
The document describes an experimental investigation into the mechanical properties of hybrid metal matrix composites reinforced with alumina, graphite, and silicon carbide. Aluminum 6063 alloy was used as the matrix material. Composites with varying compositions of the reinforcements were fabricated via stir casting. Testing showed that hardness and tensile strength increased with the addition of reinforcements. In particular, a composite with 5% silicon carbide, 5% alumina, and 5% graphite exhibited the highest hardness of 49.6 HBW and tensile strength of 133 MPa, representing an improvement over the matrix material alone.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
This summary provides the key information from the document in 3 sentences:
The document discusses a study on the austempering behavior of engineering grade ductile iron castings. Various factors were examined including heat treatment parameters, chemical composition, and nodular characteristics. The results showed that austempering temperature and time had the greatest effect on impact toughness, while higher austempering rates were achieved with additions of nickel, molybdenum, and copper to the alloy composition.
Effects of thermo mechanical simulation on the corrosion of steelJaideep Adusumelli
Performed numerous stress-strain elasticity tests along with impact test under controlled temperature and stress factors.
then the corrosion properties were studied based on the microstructures and corrosion current graphs.
The document summarizes research on aluminum 7075 alloy composites reinforced with alumina nanoparticles. Microstructural analysis found that 1.0 wt% alumina nanoparticles provided the optimal properties. Specifically:
- 1.0 wt% alumina composites exhibited maximum hardness of 134 HV and lowest wear rate. Higher amounts resulted in decreased hardness and increased wear.
- SEM images showed alumina nanoparticles were well dispersed through the aluminum matrix. Some agglomeration was observed at higher nanoparticle fractions.
- XRD analysis confirmed the presence of aluminum and alumina phases. Peak broadening and shifts indicated refinement of aluminum grains with increased nanoparticles.
- AFM images showed increased surface roughness with higher nanoparticle content
Effects of cryogenic treatment on tool steel aisi d6eSAT Journals
1. The document discusses the effects of cryogenic treatment on tool steel AISI-D6. Cryogenic treatment involves cooling tool steel to below atmospheric temperatures (around -1960°C or -3100°F) using liquid nitrogen.
2. Cryogenic treatment was found to improve the mechanical properties of AISI-D6 steel, including increased hardness, wear resistance, and toughness compared to untreated steel. This is due to the transformation of austenite crystal structure to martensite during cryogenic treatment.
3. Experiments showed that cryogenically treated AISI-D6 specimens exhibited higher hardness, lower wear rates, and increased toughness compared to conventionally heat treated specimens.
IJERD(www.ijerd.com)International Journal of Engineering Research and Develop...IJERD Editor
This document summarizes a study on the effect of heat treatment on the microstructure and mechanical properties of medium carbon steel. Two grades of steel were tested, one with copper and one without. Samples underwent various heat treatments including annealing, normalizing, quenching, and tempering at different temperatures. Hardness, ultimate tensile strength, and ductility were then measured. Results showed that steel with copper had higher hardness and strength but lower ductility. Hardness and strength decreased with increasing tempering temperature, while ductility increased. The study provides data on the mechanical properties and microstructure of heat treated medium carbon steel.
Influence of Heat Treatment on Mechanical Properties of Aisi1040 SteelIOSR Journals
This investigation is concerned to evaluate the influence of heat treatment on mechanical behavior of AISI1040 steel; it is one of the grades of medium carbon steel of American standard containing 0.40% carbon in its composition. Specimen of quenched/hardened AISI1040 steel was tempered at temperature (650,450&250℃) for 60, 90&120 minutes to modify desired properties. The mechanical behavior, particularly, ultimate tensile strength, yield strength and elongation were investigated using universal testing machine; while the hardness measurement was done on Rockwell hardness testing machine of heat treated specimens. Result shows that the ultimate tensile strength and the yield strength decrease while the elongation increases with an increase in tempering temperature and tempering time of different tempered specimen. The hardness of quenched/hardened specimen decreases with an increase in tempering temperature and tempering time. Furthermore, increasing temperature and lowering time produces approximately same result as decreasing temperature and increasing time.
This document summarizes a study on the effect of quenching media, heat treatment, and alloying elements on the properties of Al-Si-Mg alloys. The study prepared Al-Si-Mg alloys and studied how quenching in polymer solution or water, heat treatment, and adding alloying elements like B and Ti impacted properties like microhardness. Results showed that adding 0.15% B with 1% Ti improved microhardness by 57% compared to the base alloy. Quenching in polymer solution also improved thermal stability during aging at 175°C compared to water quenching. Mechanical properties were measured using ultrasound techniques and microstructure was examined using optical microscopy.
An equiaxed, submicron grain size distribution was generated in an Al (0.1 wt.% Sc) alloy by
processing through equal channel angular pressing followed by a low temperature pre-
ageing heat treatment. The alloy was subsequently annealed for various times at 300, 350,
400 and 450° C for investigating the thermal stability of the deformation microstructure. It
was found that up to 400° C, the submicron grain structure coarsens slowly and uniformly by
a process of continuous recrystallization.
Generally the prediction of behaviour of material at high temperature is very difficult. During design of
components which are subjected to or working at high temperature must consider the testing at elevated
temperature. Hot tensile testing (HTT) is the method of tensile testing of material at elevated temperature. The
materials used for automotive or aerospace applications are mostly subject to cyclic loading, high temperature
and sometimes involve high frequency vibrations. High strength aluminium alloys are one class of materials that
are widely used in the automotive and aerospace industries .In this work I test A413 material for HTT at different
temperature and strain rate, which can be used for piston.
Keywords — HTT, high temperature, strain rate, piston, automotive or aerospace.
Effect of cryogenic treatment on tool steel (aisi ¬d2)eSAT Journals
Abstract
In present scenario modernization of machine tools is on prime consideration that is an optimization of desired properties in machine tool parts means alternation of properties for that previously we employed heat treatment of steel, thus we have some improved properties but does not achieved correct solution for the problem. In modern age a new technology is comes on the front line, recognize by Acronyms C.T.P. or Cryogenic treatment of steel which has been done in cooling Atmosphere below Atmospheric tem. About – 1960C or- 3100F. During this temp. Range conversion of Austenite to marten site takes place. Thus we have got increased some desirable properties like reduced wear & Tear. Increased Hardness Micro- structure improved, Stress relieving properties also improved. In this paper tool Steel AISI- D2 is used for cryogenic treatment & study is performed regarding Micro- structure and Hardness, after Cryogenic treatment comparison is also made with un-treated test specimen.
Keywords:-AISI- D2, Cryogenic Treatment, Phase Transformation, Hardness, Micro- Structure
Effect of Quenching Media on Mechanical Properties for Medium Carbon SteelIJERA Editor
In this research work the mechanical properties of medium carbon steel has been studied . the Steel AISI 1039
quenched in different quenching media. These quenching media were cold water, water , oil and hot water.
Hardness , tensile , impact and wear tests have been carried out for specimens after quenching in different
media.
It was found that the tensile strength and hardness increased with increasing the heating temperature values of
heat treatment process. Also quenching in cold water has a great effect on tensile strength and hardness values .
where the heights value for tensile strength was (998.6N/mm²) and the hardness was (360.4 Hv) for steel which
quenching in cold water. The percentage of elongation decreased with increasing the temperature of heat
treatment process. also the lowest values of elongation was after quenching process in cold water.
However, the impact toughness and wear rate values were high for alloy after stress relief and lower after
quenching in different media. But the lowest values were recorded after quenching in cold water. It was found
that the absorbed energy and the wear rate for the alloy quenched in cold water were (23.6) J and
(2x10¯⁷gm/cm) respectively. While, for steels treated with the stress relief process were (62.02) J and
(7x10¯⁷gm/cm) respectively.
This document summarizes a study on the effects of yttrium on the mechanical properties and chemical stability of the passive film on an aluminide coating applied to 1045 steel. Samples were prepared with and without the addition of yttrium. Nanoindentation tests found that the yttrium-containing coating had greater hardness and elasticity than the yttrium-free coating. Scratch tests also showed that the passive film on the yttrium coating had a higher critical load, indicating greater resistance to failure. Electron work function measurements demonstrated that the passive film on the yttrium coating was more chemically stable. The addition of yttrium improved both the mechanical properties and chemical stability of the passive film, enhancing corrosion and
Some Results from the Investigation of Effects of Heat Treatment on Propertie...IJERDJOURNAL
Abstract:- The results of an investigation which was undertaken to reveal the differences in the mechanical properties and microstructural characteristics of two types of Ni-hard cast irons are presented in this study. The cast irons were obtained in a laboratory conditions and their compositions are in accordance with European standard EN 12513. One type of cast iron is EN GJN-HV520 (Ni-hard 2) containing 2.10% Cr and the second type EN GJN-HV600 (Ni-hard 4) with 9.04% Cr. The cast irons were evaluated in both as-cast and heat treated conditions. To improve mechanical properties specifically wear resistance, the samples of both types Ni-hard cast irons were subjected to different heat treatment processes. Annealing of Ni-hard 2 samples at 480°C during 4 hours caused increasing of hardness for about 13.5% due to additional precipitation of secondary carbides. On the other hand the heat treatment process consisting of annealing at 790°C during 4-8 hours of Ni-hard 4 samples, compared to the as-cast condition, improve the hardness for about 22.5%. In this case besides precipitation of secondary carbides, transformation of retained austenite to martensite occurs.
Welding Studies on WB36 for Feed Water Pipingijceronline
To increase efficiency, reduce emissions, cost and to reduce weight of boiler per MW, the power manufacturing sectors are going towards the once through technology (super critical boiler) instead of sub- critical. Once through supercritical (OTSC) technology has become a focal point for effective utilization of coal-based thermal power generation sector in India. Another main advantage of moving towards OTSC technology is reducing the weight of the boiler per MW, which can be done by going for material capable of handling higher pressure and temperature than the conventional material. So, in order to keep pace with these technologies, research on newer materials for every boilers line, which can operate at both higher pressure and temperature, has been initiated. So, in this article, we have taken one such feed water system and headers, where WB 36 steel (15 MiCuMoNiNb5) can be used instead conventional standard carbon steel like A106 grade B or C, which are usually used. For super critical, ultra super critical power plants this conventional materials like A106 grade B or C, leads to very thick piping system. V&M has developed WB 36 steel (15 MiCuMoNiNb5) for high pressure piping of boiler feed water system. This heat-resistant, copperalloyed ferritic steel 15MiCuMoNiNb5 has been widely used in European nuclear and conventional power plants for decades for feed water system. This widespread application is due to the toughness and strength, caused by the precipitation of copper, that are exhibited even at elevated temperatures which other fine-grained structural steels have at room temperature. The aim of this project “Welding Studies on WB36 Steel for Feed Water Piping” was taken to understand the metallurgy and the behavior of the new materials under different manufacturing operations.
SIMONA CAVALU_IDENTIFICATION OF THE URINARY STONE COMPOSITION UPON EXTRACORPO...Simona Cavalu
Abstract. The study was carried out to investigate the composition and type of different urinary
stones upon application of extracorporeal shock wave lithotripsy. ATR FTIR spectra revealed the
marker bands of a mixed stone composition containing calcium oxalate monohydrate/ calcium
carbonate, respectively calcium oxalate monohydrate/cystine. The surface morphology of the samples
and elemental analysis was performed by SEM-EDAX confirming the presence of oxalate, carbonate
and cystine in the samples. Combination of FTIR spectroscopy and SEM-EDAX allowed quantitative
and qualitative evaluation of components, the spatial distribution and the percent of major and trace
elements present in a single sample.
Stone disease evaluation in Pathology laboratory: Current prospective.Sanjeev Mehta
This document discusses metabolic evaluation and stone analysis for kidney stones. It explains that stone analysis identifies the stone composition and underlying causes, which helps determine the appropriate treatment plan. A variety of tests are used, including blood and urine tests, 24-hour urine collection to measure supersaturation levels, and analyzing the stone composition. Integrating the results of these analyses can identify metabolic abnormalities and other factors in 90-95% of cases, guiding personalized medical management and prevention of future stone recurrences.
1. Near Net Shape technologies like thixomolding and rheocasting allow for shaping metals in a semi-solid state, producing parts with tight tolerances and reduced machining compared to conventional casting.
2. Thixomolding involves reheating alloy pellets into the semi-solid state and injecting into a mold, while rheocasting uses a machine to slowly fill a mold with semi-solid metal slurry.
3. Both technologies are being applied industrially, with thixomolding common for magnesium parts and rheocasting still at a pre-industrial stage for aluminum. Examples are given of thixomolded magnesium components for applications like
Grain Refinement of Aluminum Silicon Foundry AlloysHobby Foundry
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
The document discusses various metal casting processes that use expendable molds. It describes sand casting as the most common casting method, where a sand mixture is packed around a pattern and then melted metal is poured in. Different types of patterns are discussed, including one-piece, split, match plate, and cope and drag patterns. The key molding sand ingredients and their properties are also summarized.
The document discusses various properties required for molding materials used in foundries, including refractoriness, permeability, green strength, dry strength, and hot strength. It also describes common molding materials like molding sand and core sand. Several standard tests are outlined to measure properties like moisture content, clay content, grain size, permeability, and strength. Key tests include those for moisture content, clay content, grain size distribution via sieve analysis, permeability, and compression/shear/tensile strengths at different temperatures and moisture levels. The document provides details on how to prepare standardized samples and testing procedures.
This document provides an overview of semi-solid metal forming research conducted by the CSIR in South Africa. It discusses the background of semi-solid metal forming including thixoforming and rheocasting. It describes the CSIR's approach to research, which involves developing the total product solution. Key research areas covered include processing cast and wrought aluminum alloys in semi-solid form, heat treatment, and product development. Infrastructure for research includes high pressure die casting and semi-solid billet production equipment. Research demonstrates microstructure and properties of semi-solid formed alloys can meet or exceed specifications.
Semi-solid metal casting (SSM) involves processing metals between their liquidus and solidus temperatures, when they are partially solidified. This allows for modifying the dendritic microstructure and improving mechanical properties compared to fully liquid casting. SSM techniques include thixocasting, which uses pre-cast semi-solid billets that are reheated and injected into dies, and rheocasting, where the liquid metal is sheared as it cools through the semi-solid range. SSM offers advantages over traditional casting like reduced porosity and finer microstructures, making it suitable for high-strength automotive and machine components.
This Presentation gives the information of Manufacturing process-1 of Mechanical Engineering course as per VTU Syllabus. Please write to me at: HAREESHANG@GMAIL.COM for suggestions and criticisms or visit : hareeshang.wikifoundry.com for more info.
e-mail [email protected]Effect of Heat Treatment on Some M.docxkanepbyrne80830
*e-mail: [email protected]
Effect of Heat Treatment on Some Mechanical Properties of 7075 Aluminium Alloy
Adeyemi Dayo Isadarea, Bolaji Aremob, Mosobalaje Oyebamiji Adeoyec,
Oluyemi John Olawalec*, Moshood Dehinde Shittuc
aPrototype Engineering Development Institute Ilesa, Nigeria
bCentre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife, Nigeria
cDepartment of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria
Received: April 14, 2012; Revised: September 3, 2012
This paper reports the effects of annealing and age hardening heat treatments on the microstructural
morphology and mechanical properties of 7075 Al alloy. The material was cast in the form of round
cylindrical rods inside green sand mould from where some samples were rapidly cooled by early
knockout and others gradually cooled to room temperature. From the samples that were gradually
cooled some were annealed while others were age hardened. Both the as-cast in each category and
heat treated samples were subjected to some mechanical tests and the morphology of the resulting
microstructures were characterised by optical microscopy. From the results obtained there is formation
of microsegregations of MgZn
2
during gradual solidification which was not present during rapid
cooling. It was also found out that age hardening and annealing heat treatment operation eliminated
these microsegregations and improve mechanical properties of 7075 Al alloy. It is concluded that
microsegregation can be eliminated by rapid solidification and appropriate heat treatment process.
Keywords: 7075 aluminium, microsegregation, precipitation hardening, annealing, magnesium alloy,
strength
1. Introduction
Aluminium and its alloys are used in a variety of cast and
wrought forms and conditions of heat treatment. For over
70 years, it ranks next to iron and steel in the metal market.
The demand for aluminium grows rapidly because of its
unique combination of properties which makes it becomes
one of the most versatile of engineering and construction
material1-3.
The optimum properties of aluminium are achieved by
alloying additions and heat treatments. This promotes the
formation of small hard precipitates which interfere with
the motion of dislocations and improve its mechanical
properties4-7. One of the most commonly used aluminium
alloy for structural applications is 7075 Al alloy due to its
attractive comprehensive properties such as low density, high
strength, ductility, toughness and resistance to fatigue8-11. It
has been extensively utilized in aircraft structural parts and
other highly stressed structural applications12-16.
But aluminium-zinc alloy as it is in 7075 Al alloy is
susceptible to embrittlement because of microsegregation
of MgZn
2
precipitates which may lead to catastrophic
failure of components produced from it17,18. The alloy is also
susceptibility to stress corrosion cracking19,20. This is .
1-1 Influence of Multi Extrusion Die Process on Mechanical and Chemical Behav...Ahmed Ibrahim Razooqi
INFLUENCE OF MULTI EXTRUSION DIE PROCESS ON MECHANICAL
AND CHEMICAL BEHAVIOR OF 2024-T3 ALLOY.
Ahmed Ibrahim RAZOOQI
Technical Engineering College - Baghdad, Middle Technical University, Baghdad, IRAQ
Annealing Response of Aluminum Alloy AA6014 Processed By Severe Plastic Defor...IRJESJOURNAL
Abstract: In this paper the study of micro structural stability during annealing with respect to time of conventionally grains (CG) and ultrafine-grained (UFG) of Aluminum AA6014 i s carried out. It has been observed that, the effect of the second phase magnesium-silicon particles in the CG and UFG AA6014 samples leads to a rapid hardness which increases from 40HV10 to 70HV10 within 7 days. Artificial aging shows that the material hardness even increased after 20 hours of annealing at 180°C. In total 30 hours of annealing, the hardness arrives at its maximum and then reduces due to the formation of Mg2Si precipitates, which rise in size and change their coherency. The precipitates cannot efficiently pin the dislocations and act as barriers to the dislocation motion which indicate an overall decrease in the hardness. It also has been found that the ultrafinegrained AA6014 alloy loses its thermal stability at approximately 200°C and recrystallized at 300°C. Thermal stability is strongly dependent on the material purity, second phase particles and/or oxide particles which may break up during rolling and lead to some dispersion strengthening.
“Evaluation of Corrosion Properties of Retrogression and Reaged Al 7075 alloy...IJERA Editor
The metal matrix composites offer a spectrum of advantages that are important for their selection and use as structural materials. A few such advantages are high strength, high elastic modulus, high toughness and impact resistance, low sensitivity to changes in temperature or thermal shock, high surface durability, low sensitivity to surface flaws, high electrical and thermal conductivity, minimum exposure to the potential problem of moisture absorption resulting in environmental degradation and improved machinability with conventional metal working equipment. The aim of the present study is to investigate the corrosion properties of Silicon Carbide particles (SiCp) reinforced Aluminum matrix composite after retrogression and re-aging heat treatment. Aluminum 7075 alloy with 0%, 5%, 10% and 15% SiCp were studied.
Effect of Heat Treatment on Corrosion Behavior of Spring SteelsEditor IJCATR
The experimental work deals with the effect of heat treatment on the corrosion behaviour of spring steels. In this study the
heat treatments like hardening, normalizing and tempering were done for spring steels to obtain martensitic matrix, pearlitic structure
and tempered martensitic matrix respectively. After heat treatment the microstructural studies were carried out for the samples using
SEM. Hardness measurements were done. The corrosion behaviour of all heat treated samples in HCl at different concentration (1.5N,
2N and 2.5N) was determined using Tafel extrapolation technique. The variation in the corrosion rates due to the effect of heat
treatment was noted. The results indicate that for fully martensitic matrix the corrosion rate is minimum and for pearlitic structure its
maximum. As tempering time is increased the corrosion rate increases correspondingly. The corroded microstructural images were
also taken using SEM and analysed.
Effect of artificial aging temper t6 on tensile properties of aluminum alloy ...FreddyTaebenu
Penjelasan mengenai efek dari proses artificial aging untuk melihat perilaku dari properti material paduan aluminium pada pengujian uji tarik, ditujukan untuk teman-teman yang mengambil bidang atau konsentrasi serupa dalam ilmu material engineering guna untuk menghasilkan produk dengan kualitas terbaik
The effect of Deep cryogenic treatment (DCT) on the metallurgical and mechani...Dr.M BALA THEJA
The effect of Deep cryogenic treatment (DCT) on the metallurgical and mechanical properties of Aluminium 6061-T6 is investigated in the present work
The test castings were solutionized at 525°C for 08 hrs and water quenched to room temperature. One set of samples were subjected to cryogenic treatment at -196°C in Cryo- treatment unit, while the other set is subjected to age hardening at 160°C for durations of 3 hrs, 5hrs and 7hrs. Again cryogenic treated specimens were subjected to age hardening at 165°C for durations of 3hrs, 5 hrs and 7hrs. All the samples were taken for Mechanical properties evaluation.
The total duration of the Cryogenic treatment cycle was 36 hrs, which includes 3hrs of cooling from room temperature to -196°C, 24hrs of holding and 09 hrs of warming to room temperature. The Cryogenic treatment was carried out in a specially designed Cryogenic unit
Comparison of Mechanical Properties of Austempered, Normalized and As-Weld Ca...IJAEMSJORNAL
More often than not, welded joints experience failure such as fracture which jeopardize their reliability and ergonomics when put in perspective. Attempting a significant improvement in the mechanical properties of welded joint through heat treatment could ensure joints stability and reduce the costs associated with constant repairs and replacements. In this study, the effects of heat treatments (austempering and normalization) on the mechanical properties of weldments were examined. The locally recycled steel sample was sourced from the Delta Steel Company Aladja, Delta State and the spectro-analysis was carried out on it. The test samples were machined as per properties for tests, fractured locally and were welded using shielded metal arc welding (SMAW) with stainless steel electrode. They were then heat treated in electric furnaces. The mechanical properties (tensile strength, yield strength, hardness and impact toughness) were determined and the microstructure examined using scanning electron microscope. They were also examined physically using hand lens. The result indicated that the austempered samples improved significantly in terms of its tensile strength, yield strength, hardness and ductility. It was also found that the untreated sample produced the greatest impact toughness. The result of the physical examination also suggested that heat treatment using oil based quenchant have the potential to inhibit rust at weld joints.
Corrosion Behaviour of 6061 Al-SiC Composites in KOH MediumEditor IJCATR
The present research work deals with the corrosion behaviour of 6061 Al-15% (vol) SiC(P) composites. The addition of the
reinforcement like SiC to Aluminium has been reported to decrease the corrosion resistance of the matrix due to several reasons, one
of them being galvanic action between the reinforcement and the matrix. In the present work, the corrosion behaviour of 6061 Al-15%
(vol) SiC(P) composites in KOH at different concentration (0.5M, 1M, 1.5M) and different temperature (300C, 350C, 400C, 450C, 500C)
was determined by Tafel extrapolation technique. The inhibition action of 8-Hydroxyquinoline on corrosion behaviour of 6061 Al-
15% (vol) SiC(P) composites in KOH at different concentration of inhibitor (200ppm, 400ppm); different concentration of medium
(0.5M, 1M,1.5M) and different temperature (300C, 350C, 400C, 450C, 500C) was investigated. The results indicate that corrosion rate
of Al-SiC composite in KOH increases as the concentration of medium increases and also as temperature of medium increases. The
results indicate that the inhibitor is moderately effective in inhibiting the corrosion of 6061 Al-15% (vol) SiC(P) composites. As the
inhibitor concentration increases, the corrosion rate decreases. The surface morphology of the metal surface was investigated using
scanning electron microscope (SEM). Activation energy was evaluated using Arrhenius equation, and enthalpy of activation and
entropy of activation values were calculated using transition state equation
Effect of silicon oxide sio2 reinforced particles on ageing behavior of al 20...IAEME Publication
The document summarizes research on the effect of silicon oxide (SiO2) particles on the aging behavior of an Al-2024 alloy. Key points:
- Al-2024 composites were produced with 0%, 3%, and 6% SiO2 via stir casting and subjected to heat treatments.
- Hardness, tensile strength, and wear resistance were tested for the composites in as-cast and heat treated conditions.
- Heat treatments included solutionizing at 550°C for 2 hours followed by artificial aging at 150°C for times between 1-5 hours.
- The existence of SiO2 particles was found to increase the peak hardness of the alloy and accelerate the aging kinetics compared
A refined energy-based model for friction stir processing of Al- Zn-Mg alloyIJERA Editor
Friction stir processing (FSP) is a promising solid state surface modification technique. Also, considered as an
innovative technique that the FSPwas employed to modify the surface layer of aluminium alloy. The FSP passes
of only two passes were applied on aluminium alloy samples. A rotating tool with a pin and shoulder is inserted
into a single piece of material and results in significant microstructural changes in the processed zone, due to
intense plastic deformation. It has been proved to be an effective way to refine the microstructure of aluminium
alloys, and thereby improve the mechanical properties. In procedural phenomenon there are different parameters
adjustment have been worked out to refine microstructure and several properties characterised to TEM, SEM,
FESEM and mechanical properties. In this study, a refined energy based model that estimates the energy
generated due to friction and plastic deformation is presented with the help ofexperimental and theoretical
results available in many literatures. The model is applied to 7xxx series of aluminium alloys.
A refined energy-based model for friction stir processing of AlZn-Mg alloy IJERA Editor
Friction stir processing (FSP) is a promising solid state surface modification technique. Also, considered as an
innovative technique that the FSPwas employed to modify the surface layer of aluminium alloy. The FSP passes
of only two passes were applied on aluminium alloy samples. A rotating tool with a pin and shoulder is inserted
into a single piece of material and results in significant microstructural changes in the processed zone, due to
intense plastic deformation. It has been proved to be an effective way to refine the microstructure of aluminium
alloys, and thereby improve the mechanical properties. In procedural phenomenon there are different parameters
adjustment have been worked out to refine microstructure and several properties characterised to TEM, SEM,
FESEM and mechanical properties. In this study, a refined energy based model that estimates the energy
generated due to friction and plastic deformation is presented with the help ofexperimental and theoretical
results available in many literatures. The model is applied to 7xxx series of aluminium alloys.
Study on hardening mechanisms in aluminium alloysIJERA Editor
The Al-Zn-Mg alloys are most commonly used age-hardenable aluminium alloys. The hardening mechanism is
further enhanced in addition of Sc. Sc additions to aluminium alloys are more promising. Due to the
heterogeneous distribution of nano-sized Al3Sc precipitates hardening effect can be accelerated. Mainly,
highlight on hardening mechanism in Al-Zn-Mg alloys with Sc effect is to study. In addition, several
characterisations have been done to age-hardening measurements at elevated temperatures from 120oC to 180
oC. The ageing kinetics has also been calculated from Arrhenius equation. Furthermore, friction stir processing
(FSP) can be introduced to surface modification process and hardened the cast aluminium alloys. In this study,
hardening mechanism can be evaluated by Vicker’s hardness measurement and mechanical testing is present
task.
Study on hardening mechanisms in aluminium alloysIJERA Editor
The Al-Zn-Mg alloys are most commonly used age-hardenable aluminium alloys. The hardening mechanism is
further enhanced in addition of Sc. Sc additions to aluminium alloys are more promising. Due to the
heterogeneous distribution of nano-sized Al3Sc precipitates hardening effect can be accelerated. Mainly,
highlight on hardening mechanism in Al-Zn-Mg alloys with Sc effect is to study. In addition, several
characterisations have been done to age-hardening measurements at elevated temperatures from 120oC to 180
oC. The ageing kinetics has also been calculated from Arrhenius equation. Furthermore, friction stir processing
(FSP) can be introduced to surface modification process and hardened the cast aluminium alloys. In this study,
hardening mechanism can be evaluated by Vicker’s hardness measurement and mechanical testing is present
task.
Study on Processing and Mechanical Properties of nano SiCp reinforced AA7075theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation
Magnetic nde characterization of tempered 2.25 cr 1mo steelAPOORVKRISHNA1
A descriptive presentation on heat treatment analysis of Tempered 2.25Cr-1Mo steel ,commonly known as P22 steel. The presentation includes history of the material, objective and work-plan with procedures adopted to carry out the project.
Thermodynamic characterization of metal dissolution and inhibitor adsorption ...IJRES Journal
The inhibition effect of 1-hexyl-3-methylimidazolium chloride (HMIC) on the corrosion of mild
steel in 2M sulphuric acid solution has been investigated by weight loss. potentiodynamic polarization and
electrochemical impedance spectroscopy. The effect of temperature on the corrosion behavior of mild steel in
2M H2SO4 with addition of inhibitor was studied in weight loss method at the temperature range of 308-328 K.
Results obtained that the inhibition efficiency increases with increasing the concentration of the inhibitor and
decreases with increasing the temperature. Polarization and impedance measurements were in good agreement.
The adsorption of this inhibitor on the mild steel surface obeys the Langmuir adsorption isotherm. Fourier
transform spectroscopy (FTIR) and Scanning electron microscopy (SEM) was also carried out to establish the
corrosion inhibit property of this inhibitor in sulphuric acid medium. Quantum chemical calculations were
performed using density functional theory to find out whether a clear link exists between the inhibitive effect of
the inhibitor and the electronic properties of its main constituents.
Increase of salt fog corrosion resistance of plasma nitridedJesusPZ
AISI 4340 is a commonly used alloy which is characterized by its remarkable strength, ductility and toughness obtained as a consequence of its good tempering properties [1].Because of its structural acceptable performance, AISI 4340 is widely used for fabrication of parts and components in automotive, aerospace as well as metal mechanics industries.
Thermal Expansivity Behavior and Determination of Density of Al 6061-Sic-Gr ...IJMER
Metal Matrix Composites (MMCs) covers a very wide range of materials to simple
reinforcements of castings with low cost refractory wool, to complex continuous fires lay
A Novel Method for Prevention of Bandwidth Distributed Denial of Service AttacksIJERD Editor
Distributed Denial of Service (DDoS) Attacks became a massive threat to the Internet. Traditional
Architecture of internet is vulnerable to the attacks like DDoS. Attacker primarily acquire his army of Zombies,
then that army will be instructed by the Attacker that when to start an attack and on whom the attack should be
done. In this paper, different techniques which are used to perform DDoS Attacks, Tools that were used to
perform Attacks and Countermeasures in order to detect the attackers and eliminate the Bandwidth Distributed
Denial of Service attacks (B-DDoS) are reviewed. DDoS Attacks were done by using various Flooding
techniques which are used in DDoS attack.
The main purpose of this paper is to design an architecture which can reduce the Bandwidth
Distributed Denial of service Attack and make the victim site or server available for the normal users by
eliminating the zombie machines. Our Primary focus of this paper is to dispute how normal machines are
turning into zombies (Bots), how attack is been initiated, DDoS attack procedure and how an organization can
save their server from being a DDoS victim. In order to present this we implemented a simulated environment
with Cisco switches, Routers, Firewall, some virtual machines and some Attack tools to display a real DDoS
attack. By using Time scheduling, Resource Limiting, System log, Access Control List and some Modular
policy Framework we stopped the attack and identified the Attacker (Bot) machines
Hearing loss is one of the most common human impairments. It is estimated that by year 2015 more
than 700 million people will suffer mild deafness. Most can be helped by hearing aid devices depending on the
severity of their hearing loss. This paper describes the implementation and characterization details of a dual
channel transmitter front end (TFE) for digital hearing aid (DHA) applications that use novel micro
electromechanical- systems (MEMS) audio transducers and ultra-low power-scalable analog-to-digital
converters (ADCs), which enable a very-low form factor, energy-efficient implementation for next-generation
DHA. The contribution of the design is the implementation of the dual channel MEMS microphones and powerscalable
ADC system.
Influence of tensile behaviour of slab on the structural Behaviour of shear c...IJERD Editor
-A composite beam is composed of a steel beam and a slab connected by means of shear connectors
like studs installed on the top flange of the steel beam to form a structure behaving monolithically. This study
analyzes the effects of the tensile behavior of the slab on the structural behavior of the shear connection like slip
stiffness and maximum shear force in composite beams subjected to hogging moment. The results show that the
shear studs located in the crack-concentration zones due to large hogging moments sustain significantly smaller
shear force and slip stiffness than the other zones. Moreover, the reduction of the slip stiffness in the shear
connection appears also to be closely related to the change in the tensile strain of rebar according to the increase
of the load. Further experimental and analytical studies shall be conducted considering variables such as the
reinforcement ratio and the arrangement of shear connectors to achieve efficient design of the shear connection
in composite beams subjected to hogging moment.
Gold prospecting using Remote Sensing ‘A case study of Sudan’IJERD Editor
Gold has been extracted from northeast Africa for more than 5000 years, and this may be the first
place where the metal was extracted. The Arabian-Nubian Shield (ANS) is an exposure of Precambrian
crystalline rocks on the flanks of the Red Sea. The crystalline rocks are mostly Neoproterozoic in age. ANS
includes the nations of Israel, Jordan. Egypt, Saudi Arabia, Sudan, Eritrea, Ethiopia, Yemen, and Somalia.
Arabian Nubian Shield Consists of juvenile continental crest that formed between 900 550 Ma, when intra
oceanic arc welded together along ophiolite decorated arc. Primary Au mineralization probably developed in
association with the growth of intra oceanic arc and evolution of back arc. Multiple episodes of deformation
have obscured the primary metallogenic setting, but at least some of the deposits preserve evidence that they
originate as sea floor massive sulphide deposits.
The Red Sea Hills Region is a vast span of rugged, harsh and inhospitable sector of the Earth with
inimical moon-like terrain, nevertheless since ancient times it is famed to be an abode of gold and was a major
source of wealth for the Pharaohs of ancient Egypt. The Pharaohs old workings have been periodically
rediscovered through time. Recent endeavours by the Geological Research Authority of Sudan led to the
discovery of a score of occurrences with gold and massive sulphide mineralizations. In the nineties of the
previous century the Geological Research Authority of Sudan (GRAS) in cooperation with BRGM utilized
satellite data of Landsat TM using spectral ratio technique to map possible mineralized zones in the Red Sea
Hills of Sudan. The outcome of the study mapped a gossan type gold mineralization. Band ratio technique was
applied to Arbaat area and a signature of alteration zone was detected. The alteration zones are commonly
associated with mineralization. The alteration zones are commonly associated with mineralization. A filed check
confirmed the existence of stock work of gold bearing quartz in the alteration zone. Another type of gold
mineralization that was discovered using remote sensing is the gold associated with metachert in the Atmur
Desert.
Reducing Corrosion Rate by Welding DesignIJERD Editor
This document summarizes a study on reducing corrosion rates in steel through welding design. The researchers tested different welding groove designs (X, V, 1/2X, 1/2V) and preheating temperatures (400°C, 500°C, 600°C) on ferritic malleable iron samples. Testing found that X and V groove designs with 500°C and 600°C preheating had corrosion rates of 0.5-0.69% weight loss after 14 days, compared to 0.57-0.76% for 400°C preheating. Higher preheating reduced residual stresses which decreased corrosion. Residual stresses were 1.7 MPa for optimal X groove and 600°C
Router 1X3 – RTL Design and VerificationIJERD Editor
Routing is the process of moving a packet of data from source to destination and enables messages
to pass from one computer to another and eventually reach the target machine. A router is a networking device
that forwards data packets between computer networks. It is connected to two or more data lines from different
networks (as opposed to a network switch, which connects data lines from one single network). This paper,
mainly emphasizes upon the study of router device, it‟s top level architecture, and how various sub-modules of
router i.e. Register, FIFO, FSM and Synchronizer are synthesized, and simulated and finally connected to its top
module.
Active Power Exchange in Distributed Power-Flow Controller (DPFC) At Third Ha...IJERD Editor
This paper presents a component within the flexible ac-transmission system (FACTS) family, called
distributed power-flow controller (DPFC). The DPFC is derived from the unified power-flow controller (UPFC)
with an eliminated common dc link. The DPFC has the same control capabilities as the UPFC, which comprise
the adjustment of the line impedance, the transmission angle, and the bus voltage. The active power exchange
between the shunt and series converters, which is through the common dc link in the UPFC, is now through the
transmission lines at the third-harmonic frequency. DPFC multiple small-size single-phase converters which
reduces the cost of equipment, no voltage isolation between phases, increases redundancy and there by
reliability increases. The principle and analysis of the DPFC are presented in this paper and the corresponding
simulation results that are carried out on a scaled prototype are also shown.
Mitigation of Voltage Sag/Swell with Fuzzy Control Reduced Rating DVRIJERD Editor
Power quality has been an issue that is becoming increasingly pivotal in industrial electricity
consumers point of view in recent times. Modern industries employ Sensitive power electronic equipments,
control devices and non-linear loads as part of automated processes to increase energy efficiency and
productivity. Voltage disturbances are the most common power quality problem due to this the use of a large
numbers of sophisticated and sensitive electronic equipment in industrial systems is increased. This paper
discusses the design and simulation of dynamic voltage restorer for improvement of power quality and
reduce the harmonics distortion of sensitive loads. Power quality problem is occurring at non-standard
voltage, current and frequency. Electronic devices are very sensitive loads. In power system voltage sag,
swell, flicker and harmonics are some of the problem to the sensitive load. The compensation capability
of a DVR depends primarily on the maximum voltage injection ability and the amount of stored
energy available within the restorer. This device is connected in series with the distribution feeder at
medium voltage. A fuzzy logic control is used to produce the gate pulses for control circuit of DVR and the
circuit is simulated by using MATLAB/SIMULINK software.
Study on the Fused Deposition Modelling In Additive ManufacturingIJERD Editor
Additive manufacturing process, also popularly known as 3-D printing, is a process where a product
is created in a succession of layers. It is based on a novel materials incremental manufacturing philosophy.
Unlike conventional manufacturing processes where material is removed from a given work price to derive the
final shape of a product, 3-D printing develops the product from scratch thus obviating the necessity to cut away
materials. This prevents wastage of raw materials. Commonly used raw materials for the process are ABS
plastic, PLA and nylon. Recently the use of gold, bronze and wood has also been implemented. The complexity
factor of this process is 0% as in any object of any shape and size can be manufactured.
Spyware triggering system by particular string valueIJERD Editor
This computer programme can be used for good and bad purpose in hacking or in any general
purpose. We can say it is next step for hacking techniques such as keylogger and spyware. Once in this system if
user or hacker store particular string as a input after that software continually compare typing activity of user
with that stored string and if it is match then launch spyware programme.
A Blind Steganalysis on JPEG Gray Level Image Based on Statistical Features a...IJERD Editor
This paper presents a blind steganalysis technique to effectively attack the JPEG steganographic
schemes i.e. Jsteg, F5, Outguess and DWT Based. The proposed method exploits the correlations between
block-DCTcoefficients from intra-block and inter-block relation and the statistical moments of characteristic
functions of the test image is selected as features. The features are extracted from the BDCT JPEG 2-array.
Support Vector Machine with cross-validation is implemented for the classification.The proposed scheme gives
improved outcome in attacking.
Secure Image Transmission for Cloud Storage System Using Hybrid SchemeIJERD Editor
- Data over the cloud is transferred or transmitted between servers and users. Privacy of that
data is very important as it belongs to personal information. If data get hacked by the hacker, can be
used to defame a person’s social data. Sometimes delay are held during data transmission. i.e. Mobile
communication, bandwidth is low. Hence compression algorithms are proposed for fast and efficient
transmission, encryption is used for security purposes and blurring is used by providing additional
layers of security. These algorithms are hybridized for having a robust and efficient security and
transmission over cloud storage system.
Application of Buckley-Leverett Equation in Modeling the Radius of Invasion i...IJERD Editor
A thorough review of existing literature indicates that the Buckley-Leverett equation only analyzes
waterflood practices directly without any adjustments on real reservoir scenarios. By doing so, quite a number
of errors are introduced into these analyses. Also, for most waterflood scenarios, a radial investigation is more
appropriate than a simplified linear system. This study investigates the adoption of the Buckley-Leverett
equation to estimate the radius invasion of the displacing fluid during waterflooding. The model is also adopted
for a Microbial flood and a comparative analysis is conducted for both waterflooding and microbial flooding.
Results shown from the analysis doesn’t only records a success in determining the radial distance of the leading
edge of water during the flooding process, but also gives a clearer understanding of the applicability of
microbes to enhance oil production through in-situ production of bio-products like bio surfactans, biogenic
gases, bio acids etc.
Gesture Gaming on the World Wide Web Using an Ordinary Web CameraIJERD Editor
- Gesture gaming is a method by which users having a laptop/pc/x-box play games using natural or
bodily gestures. This paper presents a way of playing free flash games on the internet using an ordinary webcam
with the help of open source technologies. Emphasis in human activity recognition is given on the pose
estimation and the consistency in the pose of the player. These are estimated with the help of an ordinary web
camera having different resolutions from VGA to 20mps. Our work involved giving a 10 second documentary to
the user on how to play a particular game using gestures and what are the various kinds of gestures that can be
performed in front of the system. The initial inputs of the RGB values for the gesture component is obtained by
instructing the user to place his component in a red box in about 10 seconds after the short documentary before
the game is finished. Later the system opens the concerned game on the internet on popular flash game sites like
miniclip, games arcade, GameStop etc and loads the game clicking at various places and brings the state to a
place where the user is to perform only gestures to start playing the game. At any point of time the user can call
off the game by hitting the esc key and the program will release all of the controls and return to the desktop. It
was noted that the results obtained using an ordinary webcam matched that of the Kinect and the users could
relive the gaming experience of the free flash games on the net. Therefore effective in game advertising could
also be achieved thus resulting in a disruptive growth to the advertising firms.
Hardware Analysis of Resonant Frequency Converter Using Isolated Circuits And...IJERD Editor
-LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region[5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits.
Simulated Analysis of Resonant Frequency Converter Using Different Tank Circu...IJERD Editor
LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region [5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits. The supported simulation
is done through PSIM 6.0 software tool
Amateurs Radio operator, also known as HAM communicates with other HAMs through Radio
waves. Wireless communication in which Moon is used as natural satellite is called Moon-bounce or EME
(Earth -Moon-Earth) technique. Long distance communication (DXing) using Very High Frequency (VHF)
operated amateur HAM radio was difficult. Even with the modest setup having good transceiver, power
amplifier and high gain antenna with high directivity, VHF DXing is possible. Generally 2X11 YAGI antenna
along with rotor to set horizontal and vertical angle is used. Moon tracking software gives exact location,
visibility of Moon at both the stations and other vital data to acquire real time position of moon.
“MS-Extractor: An Innovative Approach to Extract Microsatellites on „Y‟ Chrom...IJERD Editor
Simple Sequence Repeats (SSR), also known as Microsatellites, have been extensively used as
molecular markers due to their abundance and high degree of polymorphism. The nucleotide sequences of
polymorphic forms of the same gene should be 99.9% identical. So, Microsatellites extraction from the Gene is
crucial. However, Microsatellites repeat count is compared, if they differ largely, he has some disorder. The Y
chromosome likely contains 50 to 60 genes that provide instructions for making proteins. Because only males
have the Y chromosome, the genes on this chromosome tend to be involved in male sex determination and
development. Several Microsatellite Extractors exist and they fail to extract microsatellites on large data sets of
giga bytes and tera bytes in size. The proposed tool “MS-Extractor: An Innovative Approach to extract
Microsatellites on „Y‟ Chromosome” can extract both Perfect as well as Imperfect Microsatellites from large
data sets of human genome „Y‟. The proposed system uses string matching with sliding window approach to
locate Microsatellites and extracts them.
Importance of Measurements in Smart GridIJERD Editor
- The need to get reliable supply, independence from fossil fuels, and capability to provide clean
energy at a fixed and lower cost, the existing power grid structure is transforming into Smart Grid. The
development of a smart energy distribution grid is a current goal of many nations. A Smart Grid should have
new capabilities such as self-healing, high reliability, energy management, and real-time pricing. This new era
of smart future grid will lead to major changes in existing technologies at generation, transmission and
distribution levels. The incorporation of renewable energy resources and distribution generators in the existing
grid will increase the complexity, optimization problems and instability of the system. This will lead to a
paradigm shift in the instrumentation and control requirements for Smart Grids for high quality, stable and
reliable electricity supply of power. The monitoring of the grid system state and stability relies on the
availability of reliable measurement of data. In this paper the measurement areas that highlight new
measurement challenges, development of the Smart Meters and the critical parameters of electric energy to be
monitored for improving the reliability of power systems has been discussed.
Study of Macro level Properties of SCC using GGBS and Lime stone powderIJERD Editor
The document summarizes a study on the use of ground granulated blast furnace slag (GGBS) and limestone powder to replace cement in self-compacting concrete (SCC). Tests were conducted on SCC mixes with 0-50% replacement of cement with GGBS and 0-20% replacement with limestone powder. The results showed that replacing 30% of cement with GGBS and 15% with limestone powder produced SCC with the highest compressive strength of 46MPa, meeting fresh property requirements. The study concluded that this ternary blend of cement, GGBS and limestone powder can improve SCC properties while reducing costs.
Nunit vs XUnit vs MSTest Differences Between These Unit Testing Frameworks.pdfflufftailshop
When it comes to unit testing in the .NET ecosystem, developers have a wide range of options available. Among the most popular choices are NUnit, XUnit, and MSTest. These unit testing frameworks provide essential tools and features to help ensure the quality and reliability of code. However, understanding the differences between these frameworks is crucial for selecting the most suitable one for your projects.
Dive into the realm of operating systems (OS) with Pravash Chandra Das, a seasoned Digital Forensic Analyst, as your guide. 🚀 This comprehensive presentation illuminates the core concepts, types, and evolution of OS, essential for understanding modern computing landscapes.
Beginning with the foundational definition, Das clarifies the pivotal role of OS as system software orchestrating hardware resources, software applications, and user interactions. Through succinct descriptions, he delineates the diverse types of OS, from single-user, single-task environments like early MS-DOS iterations, to multi-user, multi-tasking systems exemplified by modern Linux distributions.
Crucial components like the kernel and shell are dissected, highlighting their indispensable functions in resource management and user interface interaction. Das elucidates how the kernel acts as the central nervous system, orchestrating process scheduling, memory allocation, and device management. Meanwhile, the shell serves as the gateway for user commands, bridging the gap between human input and machine execution. 💻
The narrative then shifts to a captivating exploration of prominent desktop OSs, Windows, macOS, and Linux. Windows, with its globally ubiquitous presence and user-friendly interface, emerges as a cornerstone in personal computing history. macOS, lauded for its sleek design and seamless integration with Apple's ecosystem, stands as a beacon of stability and creativity. Linux, an open-source marvel, offers unparalleled flexibility and security, revolutionizing the computing landscape. 🖥️
Moving to the realm of mobile devices, Das unravels the dominance of Android and iOS. Android's open-source ethos fosters a vibrant ecosystem of customization and innovation, while iOS boasts a seamless user experience and robust security infrastructure. Meanwhile, discontinued platforms like Symbian and Palm OS evoke nostalgia for their pioneering roles in the smartphone revolution.
The journey concludes with a reflection on the ever-evolving landscape of OS, underscored by the emergence of real-time operating systems (RTOS) and the persistent quest for innovation and efficiency. As technology continues to shape our world, understanding the foundations and evolution of operating systems remains paramount. Join Pravash Chandra Das on this illuminating journey through the heart of computing. 🌟
Letter and Document Automation for Bonterra Impact Management (fka Social Sol...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on automated letter generation for Bonterra Impact Management using Google Workspace or Microsoft 365.
Interested in deploying letter generation automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
Trusted Execution Environment for Decentralized Process MiningLucaBarbaro3
Presentation of the paper "Trusted Execution Environment for Decentralized Process Mining" given during the CAiSE 2024 Conference in Cyprus on June 7, 2024.
Skybuffer AI: Advanced Conversational and Generative AI Solution on SAP Busin...Tatiana Kojar
Skybuffer AI, built on the robust SAP Business Technology Platform (SAP BTP), is the latest and most advanced version of our AI development, reaffirming our commitment to delivering top-tier AI solutions. Skybuffer AI harnesses all the innovative capabilities of the SAP BTP in the AI domain, from Conversational AI to cutting-edge Generative AI and Retrieval-Augmented Generation (RAG). It also helps SAP customers safeguard their investments into SAP Conversational AI and ensure a seamless, one-click transition to SAP Business AI.
With Skybuffer AI, various AI models can be integrated into a single communication channel such as Microsoft Teams. This integration empowers business users with insights drawn from SAP backend systems, enterprise documents, and the expansive knowledge of Generative AI. And the best part of it is that it is all managed through our intuitive no-code Action Server interface, requiring no extensive coding knowledge and making the advanced AI accessible to more users.
Ocean lotus Threat actors project by John Sitima 2024 (1).pptxSitimaJohn
Ocean Lotus cyber threat actors represent a sophisticated, persistent, and politically motivated group that poses a significant risk to organizations and individuals in the Southeast Asian region. Their continuous evolution and adaptability underscore the need for robust cybersecurity measures and international cooperation to identify and mitigate the threats posed by such advanced persistent threat groups.
Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
Introduction of Cybersecurity with OSS at Code Europe 2024Hiroshi SHIBATA
I develop the Ruby programming language, RubyGems, and Bundler, which are package managers for Ruby. Today, I will introduce how to enhance the security of your application using open-source software (OSS) examples from Ruby and RubyGems.
The first topic is CVE (Common Vulnerabilities and Exposures). I have published CVEs many times. But what exactly is a CVE? I'll provide a basic understanding of CVEs and explain how to detect and handle vulnerabilities in OSS.
Next, let's discuss package managers. Package managers play a critical role in the OSS ecosystem. I'll explain how to manage library dependencies in your application.
I'll share insights into how the Ruby and RubyGems core team works to keep our ecosystem safe. By the end of this talk, you'll have a better understanding of how to safeguard your code.
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
Let's Integrate MuleSoft RPA, COMPOSER, APM with AWS IDP along with Slackshyamraj55
Discover the seamless integration of RPA (Robotic Process Automation), COMPOSER, and APM with AWS IDP enhanced with Slack notifications. Explore how these technologies converge to streamline workflows, optimize performance, and ensure secure access, all while leveraging the power of AWS IDP and real-time communication via Slack notifications.
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
HCL Notes and Domino License Cost Reduction in the World of DLAU
www.ijerd.com
1. International Journal of Engineering Research and Development
ISSN: 2278-067X, Volume 1, Issue 2 (May 2012), PP.06-17
www.ijerd.com
Impact Behavior of A356 Albite/ SiC Composites Subjected to
Cyclic Thermal Fatigue
N. E. Elzayady1, R. M. Rashad2, and A. Elhabak3
1
Ph.D Student, 2Associate Professor, and 3Professor (Department of Design and Production, Faculty of Engineering,
Cairo University, Cairo, Egypt)
Abstract––The present investigation aims to study the effects of Albite and SiC ceramics on thermal cyclic fatigue of
A356 composites containing reinforcement of weight fraction (3%) as well as the unreinforced alloy. The composites
were fabricated by rheocasting in which the particles were added into the molten alloy in semi-solid state (SSM) with
mechanical stirring at rotating speed of 700 r.p.m. The investigation emphasized on studying the impact toughness either
before or after different stages of thermal cycling. Thermal cycling tests were performed on specimens between 40 and
0
450 C for 1000 cycles. The results of study revealed that casting A356 alloy in SSM exhibited impact toughness in this
alloy (25J) as for Charpy un-notched sample. Adding 3% of Albite particles to the alloy raised its toughness to become
28J. While degradation in impact toughness has been occurred when 3% SiC was added to the alloy to reach 12J. The
results of impact test after applying the thermal cycling for all samples indicated significant improvement in their
toughness for both the A356 alloy and A356/3% Albite MMC, which showed absorbed energy of 29J and 34J
respectively, after repeated 1000 thermal cycles. An improvement in (A356/3% SiC) MMC toughness has been induced
after applying thermal cycling up to 500 cycles to reach 22J, afterwards, degradation in its value has been occurred to
reach 12J at 1000 thermal cycle. In addition, other phenomena involving the modification of matrix microstructure were
observed after conducting thermal cycling.
Keywords––Aluminum alloy, albite, SiC, MMCs, microstructure, mechanical properties, and thermal fatigue.
I. INTRODUCTION
Metal-matrix composites (MMCs) have been attracting growing interest. MMCs' attributes include alterations in
mechanical behavior (e.g., tensile and compressive properties, creep, notch resistance, and tribology) and physical
properties (e.g., intermediate density, thermal expansion, and thermal diffusivity) by the filler phase; the materials'
limitations are thermal fatigue and thermochemical compatibility [1]. Recent interest in discontinuously reinforced cast
composites in the automotive industry has focused attention on their physical and mechanical properties [2]. Thermal
fatigue is a threat in any composite system that experiences thermal cycles during use [3]. Materials undergo thermal
fatigue when subjected to thermal excursion while in use. Thermal fatigue could lead to catastrophic failure of materials,
which, in turn, damages machine elements and could lead to loss of life in severe cases. Temperature fluctuating
environments are among the most severe conditions for MMCs. This is because the matrix deform plastically when the
induced stress arising from the difference in the CTEs of the matrix and reinforcement is more than its yield strength [4].
Composites usually possess lower CTE than the matrix alloy. A low thermal expansion is desirable because it involves
low thermal strain and stress. Metals generally have high thermal shock resistance due to their high thermal conductivity
and ductility [2]. Thermal shock resistance is the material’s ability to withstand abrupt changes in temperature without
fracturing [5]. There is a shortage of many thermal data of such materials. Limited number of searches handled drastic
effects of thermal stresses on the mechanical properties. Among mechanical properties, impact strength of aluminum die
casting alloys as it is a critical mechanical property needed by designers [6]. The properties which MMCs exhibit
throughout their work life depend on the nature of the reinforcement phase(s). Consequently, different reinforcements
behave differently in the same metal matrix as a result of differences in their thermal, mechanical, and chemical
properties [4]. In the present search, A356 (Al-Si) casting alloy and two of its composites; (A 356- 3%SiC) and (A 356-
3% albite) were selected to study their behavior under thermal cyclic fatigue test and how the cycling affects their impact
toughness at different stages of cycling.
II. EXPERIMENTAL WORKS
The experimental work carried out through the present study included three stage; i) Material processing, ii)
applying thermal cycling on fabricated samples, and iii) Microstructure characterization and carrying out impact test onto
fabricated samples before as well as at different stages of thermal cycling.
2.1 Material preparation
2.1.1 Processing of materials
Three different categories of materials namely; A356 and (A356- 3%SiC) and (A356- 3% albite) MMCs were
prepared by rheo-casting technique in which the particles were added into the molten alloy in semi-solid state (SSM) with
mechanical stirring at rotating speed of 700 r.p.m. SiC particles’ size ranged from 20-90 µm and albite one was from 2-
20 µm. Albite is a common feldspar ceramic; a mineral aluminosilicate (NaAlSi 3O8) that occurs most widely in acid
6
2. Impact Behavior of A356 Albite/ SiC Composites Subjected to Cyclic Thermal Fatigue
igneous rocks such as granites, It's basically consisting of silicates [7], it’s composition is ; (67%SiO 2 , 19%Al 2 O 3 ,
and 11% Na 2 O). The processing details of (A 356- 3% albite) are according to ref. [8] and processing of (A356- 3%SiC)
is as in ref. [9].
2.1.2 Sampling
Large Number of un-notched impact specimens with dimensions 10×10×55 mm was prepared from cast ingots to
investigate impact behavior of selected materials in different conditions.
2.2 Thermal Cyclic Fatigue Test
Cast samples were subjected to hundreds of repeated thermal cycles during carrying out thermal fatigue test with a
specially designed apparatus. The heating process was conducted in resistance furnace and current water was used for
cooling samples, a schematic diagram of working set-up is shown in figure (1). Thermal cycling was applied onto 4
patches at stages; 250, 500, 750 and 1000 cycles. In which each stage has own patch samples and each 20 samples are
thermally cycled in one time. Repeated cycles were performed as; 12 continuous working hours followed with brake of
12 ones and then started again. Calibration of temperature measurement was applied at pretest stage because of the
difficulty of obtaining readings from movable samples during thermal cycling. Dummy samples were holed to insert
isolated thermo couple inside as shown in figure (2.a). Simulation for thermal test conditions was carried out several
times till reaching steady temperature readings. Temperature measurements were with about 11% errors. Measured
heating temperatures equaled (450 - 500 C) i.e average one is 475 C while cooling was 40 C. The thermal cycle
profile is charted in figure (2.b).
Figure 1: Schematic diagram of working setup
7
3. Impact Behavior of A356 Albite/ SiC Composites Subjected to Cyclic Thermal Fatigue
(a) (b)
Figure 2: (a); Temperature measurement onto dummy sample, (b); Thermal cycle profile
2.3 Material Characterization
2.3.1 Microstructure Characterization
2.3.1.1 Optical Microscopy
Samples were cut from ingots for carrying out metallurgical studies following the standard metallographic procedure.
The echant used was Keller’s reagent. The microstructure was conducted on the surface of polished samples using Olympus-
12 optical microscope.
2.3.1.2 Fractography
Fracture characteristics were studied to understand the fracture mechanism. The fracture surfaces were observed by
scanning electron microscope (Joel JSM 5410) using (Oxford-IMCA) for scanning electron micrographs.
2.3.2 Mechanical Characterization
The present investigation emphasized on impact test among different mechanical tests.
2.3.2.1 Impact test
Impact test was performed using RKP 450 Pendulum impact testing machine with capacity of 350 Joule and testing
temperature 20.7 C. Five patches were tested; before thermal cycling, after 250, 500, 750, and 1000 cycles.
III. RESULTS AND DISCUSSION
3.1 Dimension stability and surface observation
The use of aluminum and its alloys exposed to fluctuating-temperature environments is limited by their dimensional
stability. Dimensional instability can cause malfunctioning and catastrophic failures of structural components which could
lead to loss of life in severe cases [4]. In the present study, on the macro scale observation and measurements for samples
before and after 1000 thermal cycles, it shows no deformation and insignificant change in dimensions of the thermally cycled
samples for 1000 cycles, more over, sound surface and no cracks were observed onto samples. Figure (3) shows pictorial
photos at different stages of thermal cycling. The result similar to W.A. Uju [4], who studied A535 and its MMCs during
thermal cycling between 40 and 300 C for only 10 thermal cycles. Sanjeev Kumar [10], Observed the effect of thermal
cycling on the dimension stability of cast aluminium composites reinforced with SiC and Fly ash particles in which samples
were subjected to a compressive load of 74.9 N before thermal cycling between 400–450 C for heating and room
temperature for cooling, in which cooling was conducted by air under forced convection. His study revealed that after the
five thermal cycling, the deformations were occurred and the change of dimensions is found to be many order of mm, he also
proved that the addition of fly ash up to 15% by weight improved the dimensional stability of specimen rather than either
unreinforced alloy or with adding SiC.
Sobczak et al [2] have studied higher number of thermal cycles between 40-370 C onto cast aluminum-matrix
composites; they proved that obvious deformation has been occurred in AlSi12CuNiMg squeeze-cast and heat-treated (T6)
alloy after 5000 cycles, also surface cracks have been occurred on in AlSi25 gravity cast after 1300 cycles, and less crack
length in AlSi20 gravity cast after 1500 cycles while AlSi12CuNiMg squeeze-cast and heat-treated (T6) alloy shows less
cracks length after 5000 cycles. Also AlSi12CuNiMg/22 vol.% Al2O3 squeeze cast composite had the least surface crack
length after 5000 cycles.
8
4. Impact Behavior of A356 Albite/ SiC Composites Subjected to Cyclic Thermal Fatigue
Figure 3: Pictorial photos of impact samples for (a); A356, (b); (A356-3% SiC) MMC and (c); (A356-3% albite) MMC at;
(I); before thermal cycling, (II); after 250 cycles, and (III); after 1000 thermal cycles.
3.2 Microstructure
3.2.1 Optical Microstructure
Optical images of samples before and after thermal cycling are shown in figures 4-6 for unreinforced A356 alloy, and
(A356-3% SiC) and (A356-3% albite) MMCs respectively. The observations of the microstructure before applying thermal
cycling are shown in figures (4.a, 5.a, and 6.a). As it is indicated from figure (5.a) that present coarse SiC particle in the
molten metal during casting helped pushing grains away leading to coarse grains formation during solidification process, also
this composite distinguished with associated porosity at matrix-particle interface. On contrary, figure (6.a) exhibited the
finest matrix grains in (A356-3% Albite) MMC. This is perhaps attribute to double refining mechanisms, the first; present
fine particles in the molten which acts as nuclei during casting and hence accelerate the solidification process, and the
second; the chemical composition of Albite ceramic (NaAlSi3O8) which contains Na that enhanced refining effect. The
distribution of Albite particles is not clear on related optical magnification of figure (6.a), while SEM section dealt with this
item. On the other hand, observation of microstructure after thermal cycling test (figure (4.b, 5.b, and 6.b).) exhibits absence
of internal cracks in the optical images. Also the optical microstructure investigation reveals that applying thermal cycling on
samples produces an effective change on the morphology of the eutectic acicular silicon to fibrous form; this change has been
observed in all studied materials. The structure improvement can be explained based on the materials characteristics;
basically, thermal cycling circumstances play essential role in the delivered results, particularly, both heating and cooling
temperatures. In some engineering processes like hot rolling or extrusion, the working temperature of some Al alloys is on
the same level as the solution treatment temperature of certain Al alloys. So it may possible to quench these products
immediately by forced air or water spray to modify the structure and hence mechanical properties [11]. In the same manner,
in the present study, according to the thermal cycles profile (figure (2.b)), materials during thermal cycling underwent temper
resemble to T6 in repeated manner (repeated short heating periods at T ava. = 475 C followed with quenching in water at
room temperature). T6 treatment includes heating to about 500 C, solution heat treatment for certain period of time that
changed according to the cross section of sample then quenching in water followed by artificial or natural ageing. T6 of heat
treatment is well known with its effective change on the morphology of the sharp eutectic silicon to fibrous particles in A356
alloy [12]. In the present study, it is very essential to explain the mechanism of changing Si phase. Actually, morphology
change of Si phase was occurred gradually with increasing thermal cycling number as it is clear from the microstructure
examination of A356 alloy after each stage of thermal fatigue test (figure (7)), the same behavior of matrix has been obtained
in both its MMCs . This interprets that despite of the very short period of heating time during the one thermal cycle (figure
(2.b)) which is not enough for the phase transformation (Si form) but the repeated action during thermal cycling save enough
time required for accomplish this transformation. Erhard [12] stated that silicon spheroidization in hypoeutectic Al-Si alloys
could be obtained at different levels of heating temperature and different soaking time during heat treatment, in a modified
Al-Si alloys (thixoformed), completely spheroidization of Si phase could be accomplished within minutes at 500°C < T <
540°C. Badini [13], proved that for the thermal cycling between 25 and 220 °C of 2014/Al2O3-SiO2 (Saffil® fibers)
composite after 1000 cycles; the microstructure of the matrix of T6 treated composites was unchanged after thermal cycling
and characterized by the presence of precipitates heterogeneously nucleated near the fiber interfaces. On the contrary, thermal
cycling of as-cast composite resulted in an increased content of precipitates, heterogeneously nucleated at the matrix/fiber
interfaces. Also Badini observed strong damage into long fibre during cycling. Sobczak [2], observed obvious internal cracks
in the optical microstructures images of both of squeeze-cast and T6 heat-treated AlSi12CuNiMg alloy, and
AlSi12CuNiMg/22 vol.% Al2O3 composite after 5000 thermal cycles in which severer crack in unreinforced alloy than that
in the composite.
9
5. Impact Behavior of A356 Albite/ SiC Composites Subjected to Cyclic Thermal Fatigue
(a) (b)
Figure 4: Microstructure of A356 (a); before thermal cycles and (b); after repeated 1000 thermal cycling
(a) (b)
Figure 5: Microstructure of (A356-3% SiC) MMC (a); before thermal cycles and (b); after repeated 1000thermal cycling
(a) (b)
Figure 6: Microstructure of (A356-3% albite) (a); before thermal cycles and (b); after repeated 1000 thermal cycling
10
6. Impact Behavior of A356 Albite/ SiC Composites Subjected to Cyclic Thermal Fatigue
(a) (b)
(c) (d)
Figure 7: Microstructure of A356 alloy after; (a): 0.0 cycles, (b): 250 cycles, (c): 500 cycles, and (d): 1000 cycles.
3.2.2 Scanning Electron Microscope (SEM) and EDAX Analysis
The surface examination of (A356-3%Albite) MMC by SEM is shown in figure (8). A uniform distribution of 3% Albite
particles inside the matrix alloy without agglomeration and round geometrical aspect of Albite particles are clear from figure
(8.a). Also Albite particle size is measured and analyzed as in figure (8.b) by EDAX. The analysis of ceramic particle is
shown in figure (8.c).
(a) (b)
11
7. Impact Behavior of A356 Albite/ SiC Composites Subjected to Cyclic Thermal Fatigue
(c)
Figure 8: (a); SEM, (b); Detail [A], and (c); EDAX analysis for (A356-3%Albite) MMC.
3.3 Impact results
3.3.1 Impact strength of material before thermal cycling test
The results of impact toughness of A356 alloy and composites reinforced with both Albite and SiC particles before
thermal cycling are graphed in figure (9.a). As it is clear from figure (9.a), adding 3% Albite particles to A356 alloy has
increased the absorbed energy from 25 J to 28 J. On contrary, present SiC in the A356 alloy deteriorate its impact toughness
where as the absorbed energy has been lowered down to 11.2 J. The enhanced toughness (A356-3% Albite) MMC is
attributed to microstructural improvement due presence of Albite dispersions into the matrix as it was explained in the
microstructure characterization. While declination in the (A356-3% SiC) MMC’s is because of SiC particles sharp adages
and coarser grains of its matrix alloy beside associated porosity at matrix-particle interface (figure (5.a)).
3.3.2 Effect of thermal cycling on the impact strength of cast A356 alloy and (A356-3% Albite) MMC
The results at different thermal cycling stages are shown in figure (9.b). The present investigation, is studying the effect
of applying thermal cycling on the impact behavior of A356 alloy and its composites. As it well known that the elevated
deterioration in mechanical properties with increasing thermal fatigue cycles is the ordinary trend in practical service, this is
based on increasing associated thermal stresses. From the present study, unordinary behavior of impact strength has been
observed into studied materials. Where as the results graphed in figure (9.b) reveal that the toughness of A356 alloy and its
composite reinforced with Albite particles is decreased by 54 and 51% respectively after subjecting to 250 repeated thermal
cycles, this stage is a very critical interval in the thermal cycling test of the present investigation, thus, relevant
comprehensive explanation will be conducted later in this paragraph. After the first stage (250 cycles), gradual improvement
of toughness was obtained as they subjected to more thermal cycles number. More over, the values of toughness of both
unreinforced alloy and its composite reinforced with Albite ceramic particles after ending thermal fatigue test (after1000
cycles) exceeded that those before applying thermal cycling as the absorbed energy increased from (25 to 29 J) and from (28
to 34 J) for A356 alloy and (A356/3% Albite) MMC respectively. Definitely, the obvious gradual change in Si eutectic
morphology from acicular to fibrous form due to applying thermal cycling onto the samples as it was explained in the
microstructure section, is the main reason of enhancing the toughness of the thermally cycled materials. This explained the
gradual increase of the material toughness as the thermal cycling advances starting beyond the first stage (250 cycles). Erhard
[12] recorded about 11J absorbed energy for notched Charpy samples of A356 alloy after subjecting to silicon
spheroidization treatment instead of conventional and expensive T6 solution heat treatment. His treatment was applied by
soaking thixoformed samples at 540 C for 3 minute followed with cooling in water or air. This conclusion means that during
practical application improving properties are possible without relaying on additional processes and cost. On the other hand,
the results were obtained in the present investigation doesn't mean that the enhanced toughness trend is going to ever last
with additional cycles. This is because of handling intermediate interval of thermal cycling (1000 cycles) in the present study
has been adopted, even temperature excursion in which was severe. Probably, at advanced cycling time, occurrence of
gradual degradation in material properties is expected. This due increasing of thermal stresses which are always relieved by
crack formation or plastic deformation that lead to deterioration in the material properties.
Again in the present investigation, an explanation for the dramatic declination in impact toughness obtained after 250
thermal cycles; it is may be refers to the formation of some undesirable precipitates during this time interval of thermal
fatigue test (250 cycles) which could harden the materials and affected their ductility at this period. As it well known that the
time factor is very essential in thermal treatment process so its period should be adjusted because either less or more time
value could lead to undesirable structure and hence causes deterioration in the mechanical properties. However, perhaps
modified precipitates have been formed during the advanced cycling number and caused great enhancing in ductility values.
This conclusion agreed with Badini [13] who explained that the material in his study (both 2014 and its composites) undergo
rapid solidification and cooling during casting, in which they stay at high temperature for periods not sufficiently long for
allowing precipitation phenomena of strengthening secondary phases, and afterwards, strengthening by precipitation may
occur during the thermal cycling, which involves sample heating for long discontinuous time. Any how, more investigation
should be considered to study this phenomenon.
12
8. Impact Behavior of A356 Albite/ SiC Composites Subjected to Cyclic Thermal Fatigue
3.3.3 Effect of thermal cycling on the impact strength of (A356-3% SiC) MMC
Adding SiC particles to A356 alloy leads to causing variant effect of thermal fatigue on the impact behavior of this
composite, figure (9.b) indicated that, slight decrease in toughness value has been occurred after subjecting to 250 repeated
thermal cycles where as the absorbed energy changed from 11.2 to 10.5J, perhaps the variant behavior of (A356 -3% SiC)
MMC at the first stage is because it has already low toughness before applying thermal cycling. On the other hand, distinct
increase in the toughness value has been achieved after 500 cycles that it reached 22J while again gradual degradation has
been occurred afterwards as it lowered down to 17.5 then 12 J absorbed energy after 750 and 1000 cycles in sequence.
Actually, the improvement of toughness is mainly refers to modification of Si morphology as well as the behaviour of
unreinforced alloy and (A356 -3% Albite) MMC. While the later degradation in its values in impact toughness is most
probably due to particle–matrix interfaces decohesion during thermal cycling. The decohesion occurs as a result of
localization of strains due to the CTE mismatch which increases with higher thermal cycling. This finding is agrees with
Sharmilee et al study [14].
40
30
35
25
30
20
Energy (J)
25
Energy (J)
15
20
10
15
5
10
0 5
rrin
g MC MC
sti )M ) M 0
ith Si C alb
ite
tw % 0 cycles 250 cycles 500 cycles 750 cycles 1000
cas L/3 /3% cycles
6A AL
(35 (356
Number of cycles
Material
AL-356 (AL-356/3%SiC) MMC (AL-356/3%albite) MMC
(a) (b)
Figure 9: (a); Impact energy before thermal cycling, and (b); at different thermal cycling stages.
Finally, the experimental results of impact toughness revealed that excellent toughness was for (A356-3% albite) MMC
followed by that of unreinforced A356 alloy while the lowest value was for (A356-3% SiC) MMC, where as the absorbed
energies after thermal fatigue ending were 34, 29 and 12J for the materials in sequence.
It’s noteworthy to show that the broken impact samples with high toughness values either before or after thermal cycl es have
been bent with some degrees proportional to its ductility. Pictorial photos of broken samples in figure (10) confirm the impact
energy results that graphed in figures (9.a) and (9.b).
I II
Figure 10: Pictorial photos of fracture zone of broken impact samples for (a); A356, (b); (A356-3% SiC) MMC and (c);
(A356-3% albite) MMC at (I); before thermal cycling, and (II); after 1000 thermal cycles
13
9. Impact Behavior of A356 Albite/ SiC Composites Subjected to Cyclic Thermal Fatigue
3.4 Fractogragh
Fractographic examination of metals is used in metal science to evaluate the cause of material destruction by revealing
and identifying internal discontinuities such as internal cracks, porosity, inclusions. Also to determine the decohesion
mechanism by classifying the characteristic morphological features of the fracture surface [15].
3.4.1 Fractogragh examination of samples before thermal cycling
Figures 11–13 show the SEM fracture images of the tested materials before thermal cycling. Figures (11 and 13)
indicates that the fracture surface of both unreiforced A356 alloy and (AL356-3% albite) MMC is distinguished with taking
place plastic deformation in the aluminum solid solution resulting in the bands of the dimples formation implies cleavage
planes of the brittle fracture between them which can be a result of the mixed (dimple-brittle) mechanism of fracture. While
weakly-developed surface and cleavage planes of brittle fracture is obvious in (A356-3% SiC) MMC (figure (12)). These
morphological features of the fracture surfaces have proved the significant increase of impact toughness of both A356 alloy
and (A356-3% albite) MMC rather than that of the composite reinforced with SiC particles. Accually, formation of mixed
fracture demands higher energy input which is consumed in plastic deformation compared with brittle cracks. Where as the
energy absorbed during plastic deformation, causes an activation of the slip systems in successive micro-regions [15].
(a) (b)
Figure 11: (a); Impact fractograph of stirred unreinforced A 356 alloy before thermal cycling and (b); Detail [A].
(a) (b)
Figure 12: (a); Impact fractograph of (A356-3% SiC) MMC before thermal cycling and (b); Detail [A]
14
10. Impact Behavior of A356 Albite/ SiC Composites Subjected to Cyclic Thermal Fatigue
(a) (b)
Figure 13: Impact fractographs of (A356- 3% albite) MMC before thermal cycling (a); small magnification and (b); higher
magnification.
3.4.2 Fractogragh examination of samples after applying thermal cycling
Figures 14-16 show the SEM fracture images at two locations of each impact sample after applying thermal cycling.
Bands of the dimples formation were observed in A356 alloy (Figure (14.a)), also mixed dimple-brittle fracture is shown at
other locations (figure 14.b). Basically, the mixed fracture mechanism in A356 subjected to thermal cycling is most probably
due to the modification of Si morphology. As Małgorzata [15] explained that Plastic deformation could take place in the -
aluminum solid solution resulting in the bands of the dimples formation which can be a result of the mixed mechanism of
fracture in most cases in alloys of modified silicon morphology. Also fracture images of (A356-3% albite) MMC indicate
clear mixed dimple-brittle fracture mechanism in figure (16.a) and undergoing this composite interdendritic fracture as shown
at other locations (figure (16.b)). The dendrite fracture is most probably occurred due to voids coalescence arisen from
shrinkage porosity during material processing [16] and enhanced during thermal cycling due to induced thermal stress. While
weakly-developed surface and cleavage planes of brittle fracture is obvious in (A356-3% SiC) MMC (figure 15.a) and it is as
the case before applying thermal cycling. More over, fracture is characterized with propagated cracks (figure (15.a) and
(15.b)). Perhaps severe cracks propagation is due concentrated thermal stress at sharp edges of SiC particles. The crack
propagation is in some cases of brittle materials, very fast, it is sometimes estimated as equal to 0.7 times the speed of sound
[15].
However, the above explanation of fracture mechanisms interpret the nature of fracture zone of broken samples at
(figure (10.b).II) where as composite reinforced with SiC has straight fractures zone without significant bending (i.e it has
lower ductility and hence no significant plastic deformation). While both unreinforced alloy and (A356- 3% albite) MMCs
have bent fractured zones (figure (10.a).II and (10.c).II) respectively) which reveal higher ductility of those material. Also
photos of fractured impact samples in positions (I) and (II) (figure (10)) reveal that the materials behaved the same fracture
manner both before and after thermal cycling.
(a) (b)
Figure 14: Fractographs of unreinforced A356 alloy after 1000 repeated thermal cycles at two different locations (a) and (b).
15
11. Impact Behavior of A356 Albite/ SiC Composites Subjected to Cyclic Thermal Fatigue
(a) (b)
Figure 15: Fractographs of (AL356-3%SiC) MMC after 1000 repeated thermal cycles at two different locations (a) and (b).
(a) (b)
Figure 16: Fractographs of (AL356-3%albite) MMC after 1000 repeated thermal cycles at two different locations; (a) and
(b).
Finally, as a benefit of using MMCs rather metal alloys, their intermediate properties. Variation in those properties is
definitely huge, so intensive studies should be conducted in this field to provide designers right approach for selecting proper
material. The results obtained from present investigation make (A356-3% albite) MMC a candidate material in relevant
thermal application rather than both (A356-3% SiC) MMC and unreinforced A356 alloy.
IV. CONCLUSION:
1. The high toughness values (28 J) of (A356- 3% albite) MMC is mainly due to grain refining effect in the matrix
alloy which refers to fineness and chemical composition of Albite ceramic, beside geometrical features of rounded
Albite particles.
2. Adding 3 % of SiC particles to A356 alloy have dramatically decreased its toughness; whereas the absorbed energy
changed from 25J in the unreiforced A356 alloy to 11.2J in the (A356- 3%SiC) MMC before applying cyclic
thermal fatigue, is due to sharp- irregular edges of SiC particles and associated matrix-interface stress localization.
Beside associated porosity at matrix- particle interface.
3. The thermal fatigue behaviour of both unreinforced and their metal matrix composite is controlled by matrix
structure change during thermal cycling. Where as conducting cyclic thermal fatigue on the materials produced
gradual change on the morphology of the eutectic acicular silicon to fibrous form in A356 matrix alloy.
4. Applying thermal fatigue cycling up to 1000 cycles onto A356 alloy as well as on (A356- 3% Albite) MMC has
improved their toughness; whereas the absorbed energy has been changed from 25 to 29 J and from 28 to 34 J
before and after cyclic test in these materials respectively.
5. Despite obtaining an increase into (A356- 3%SiC) MMC toughness at the intermediate stage of cyclic thermal
fatigue (500 cycles) in which the absorbed energy has been changed from (11.2 to 22 J) at this stage, but gradual
degradation in this value has been occurred at advanced cycling stages. This is most probably due to interference-
decohesion between matrix and particles arising from mismatch of CTE during thermal cycling and stress
concentration at sharp SiC particles’ edges.
6. Even though high CTE mismatch between the matrix and albite ceramic but its rounded geometry benefit make
(A356- 3% albite) MMC has the highest toughness value after undergoing 1000 repeated thermal cycles. Beside,
16