Al2O3/Metal composite ceramics were fabricated by the use of mechanical milling and pressureless sintering. Al2O3 + 10 vol.% of La, Mn, Si or Y were mixed and milled during 12 h at 300 rpm in a horizontal mill, then with the powder mixture it was conformed cylindrical samples by uniaxial pressing using 300 MPa. Pressed samples were sintered during 2 h in an electrical furnace at 1500°C. During sintered it was used an argon atmosphere inside the furnace in order to inhibit metal oxidation. XRD results indicate that alumina and metals retain its crystalline structure. Reached density by samples is small and less than 90%. Scanning electron microscopy observations show alumina’s microstructure with very fine and homogeneous distributions of metal particles. Both the Mn and Si are not suitable metals to improve the mechanical properties of alumina, in particular the fracture toughness. Considered rare earth metals such as yttrium and lanthanum, have yielded favorable results in improving the fracture toughness of the alumina. However, it should be made more dense materials with them to better explore this potential.
Improving Fracture Toughness of Mullite Ceramics with Metal ReinforcementsIJRES Journal
Mullite/Metal composite ceramics were fabricated by the use of mechanical milling and pressureless sintering. Al2O3 + 10 vol.% of Co, Ni, or Ti were mixed and milled during 12 h at 300 rpm in a horizontal mill, then with the powder mixture it was conformed cylindrical samples by uniaxial pressing using 300 MPa. Pressed samples were sintered during 2 h in an electrical furnace at 1500°C. During sintered it was used an argon atmosphere inside the furnace in order to inhibit metal oxidation. XRD results indicate that alumina and metals retain its crystalline structure. Measurements of densities indicate that they were achieved relative densities between 90% and 98% in the manufacture composites. Optical microscopy observations show mullite’s microstructure with very fine and homogeneous distributions of metal particles. Used metals (Co, Ni and Ti) to reinforce mullite, have yielded favorable results improving the fracture toughness of the mullite. However, it should be made more dense materials with them to better explore this potential.
SiC and ZrO2 Weigh Percentage Effects on Microstructure of Al Based Matrix Co...INFOGAIN PUBLICATION
SiC and ZrO2 particle are succesfully reaction synthesized from powder of Al, ZrO2 and SiC using spark plasma sintering method. The XRD of sintered composite and microstructure of the aas-sintered products. With the ZrO2 content increasing, the grains are remarkably refined and the and the ZrO2 and nano SiC particles are dispersing more uniformly in Al matrix, forming a homogeneous structure with the least porosity.
Improving Fracture Toughness of Mullite Ceramics with Metal ReinforcementsIJRES Journal
Mullite/Metal composite ceramics were fabricated by the use of mechanical milling and pressureless sintering. Al2O3 + 10 vol.% of Co, Ni, or Ti were mixed and milled during 12 h at 300 rpm in a horizontal mill, then with the powder mixture it was conformed cylindrical samples by uniaxial pressing using 300 MPa. Pressed samples were sintered during 2 h in an electrical furnace at 1500°C. During sintered it was used an argon atmosphere inside the furnace in order to inhibit metal oxidation. XRD results indicate that alumina and metals retain its crystalline structure. Measurements of densities indicate that they were achieved relative densities between 90% and 98% in the manufacture composites. Optical microscopy observations show mullite’s microstructure with very fine and homogeneous distributions of metal particles. Used metals (Co, Ni and Ti) to reinforce mullite, have yielded favorable results improving the fracture toughness of the mullite. However, it should be made more dense materials with them to better explore this potential.
SiC and ZrO2 Weigh Percentage Effects on Microstructure of Al Based Matrix Co...INFOGAIN PUBLICATION
SiC and ZrO2 particle are succesfully reaction synthesized from powder of Al, ZrO2 and SiC using spark plasma sintering method. The XRD of sintered composite and microstructure of the aas-sintered products. With the ZrO2 content increasing, the grains are remarkably refined and the and the ZrO2 and nano SiC particles are dispersing more uniformly in Al matrix, forming a homogeneous structure with the least porosity.
Preparation and Investigation on Properties of Cryogenically Solidified Nano ...IJERA Editor
In the present work, AL-alloy containing 12% silicon (LM 13) matrix nano composites were fabricated in sand moulds by using copper end blocks of copper end chill thickness 10 &15 nm with cryogenic effect . The size of the reinforcement (NanoZro2) ranges from 50-80nm being added ranges from 3 to 15 wt % in steps of 3 wt % . Cryogenically solidified Nano Metal Matrix Composites were compressed by using hydraulic compression machine. Specimens were prepared according to ASTM standards and tested for their strength, hardness and fracture toughness. Micro structural studies of the fabricated Nano Composites indicate that there is uniform distributions of reinforcements in the matrix materials (LM 13). An increasing trend of hardness, UTS & fracture toughness has been observed. The best results have been obtained at 12 wt %. The results were further justified by comparing two copper end chill thickness 10 &15 mm. Finally the Volumetric Heat Capacity of the cryo-chill is identified as an important parameter which affects mechanical properties.
A Study on Mechanical Properties of Fly Ash and Alumina Reinforced Aluminium ...IOSR Journals
The results of an experimental investigation of the mechanical properties of fly ash and Alumina
reinforced aluminium alloy (LM25) composites samples, processed by stir casting route are reported in this
paper. Three sets of composites with constant weight fraction of fly ash (particle size of 3-100 μm) and
Al2O3(particle size of 150 μm) with different wt% were used. Composite samples have the reinforcement weight
fractions of constant 3% fly Ash and varying %wt of 5, 10 and 15% Al2O3 . The main mechanical properties
studied were the tensile strength,ductilityimpact strength & hardness. Unreinforced LM25 samples were also
tested for the same properties. It was found that the tensile strength & hardness of the aluminium alloy (Lm25)
composites increases with the increase in %wt of Al2O3 upto certain limit. in addition of more amount of
reinforcement the Tensile strength decrease due to poor wettability of the reinforced material with metal
aluminium matrix .And the charpy test shows decrease in impact load absorption with increase in %weight
reinforcement.The Microstructure study of the samples indicated near uniform distribution of the fly ash and
Al2O3 particles in the matrix. LM25 alloy is mainly used where good mechanical properties are required in
castings of a shape or dimensions requiring an alloy of excellent castability in order to achieve the desired
standard of soundness.The alloy is also used where resistance to corrosion is an important consideration
particularly where highstrength is also required.
DEVELOPMENT AND TRIBOLOGICAL CHARACTERIZATION OF DUAL PARTICLE AND TRIPLE PAR...ijmech
The this work the study on hardness and wear behaviour of dual particle and triple particle size Alumina (Al2O3) reinforced aluminium alloy based metal matrix composite (Al2O3-Al MMC) was carried out. AlMMCs were prepared using 10 vol% Al2O3 reinforcement into aluminium metal matrix and developed using stir casting process. Stir casting is a most suitable process for the production of particulate MMC in which the reinforcement is introduced in to the molten matrix material with simultaneous stirring. The reinforcement in the range of particle size with Dual particle and Triple particle at 10% olume fraction with range from coarse to fine size were used (210µ, 180µ, 80µ & 10µ).The hardness of the composite was
determined by Vickers hardness tester and Brinell Hardness Tester. Tensile strength was determined by Universal Testing Machine (UTM). The wear rate was found by pin-on-disc type wear testing machine with steel disc of 60HRC hardness in dry sliding condition. Wear test was conducted on all the samples
at speeds of 300,600 and 900 rpm by varying the load (2kg, 4kg, 6kg & 8kg) at a constant sliding distance of 55mm. The wear track studies were carried out by optical microscope .The test results showed that Dual particle composite and triple particle composite exhibited better hardness compared to as cast AL- 7075. Strength of Triple particle reinforced MMC was found to be higher than that of dual particle reinforced composite material. The wear resistance properties of dual particle MMC was higher compared to triple particle reinforced MMC. The secondary process will further enhances the wear resistance of the composite and also that heat treatment will promote the wear resistance.
Investigation of Mechanical Properties of Aluminium Based Metal Matrix Compos...IJERA Editor
Present study is focused on the fabrication of aluminium 6061 based metal matrix composites, Reinforced with
silicon carbide and Al2O3 by stir casting technique. The percentage of one reinforcement particulate is kept
constant and varying other and vice versa, namely typeI and typeII composites. The various mechanical tests like
tensile strength test, hardness test, wear test and Impact strength performed on the samples obtained by stir
casting technique for comparison purpose. The result indicated that the developed method is quite successful and
there is an increase in the value of tensile strength, hardness value and Impact strength of newly developed
composite having (SiC + Al2O3) particulates in comparison to the Aluminium.
Wear characteristics of pure aluminium, al alloy & al-alumina metal mtrix...eSAT Journals
Abstract In this report, an aluminium metal matrix was reinforced with 1.5 wt. % of Al2O3 nano particles using non-contact cavitation method to prepare the metal matrix nano composite. Microstructural examination conducted on the sample revealed a uniform distribution of alumina particulates. Sliding wear behavior of the as-cast MMNC was studied in dry condition, under different test conditions by varying the load and the sliding velocity, with an unlubricated Multiple Tribo Tester. It was found that sliding wear resistance improved considerably with the addition of alumina nano particles. Microscopic examinations of the worn out surfaces of pure Al, Al-alloy (duralumin) and MMNC reveal that the MMNC has greater resistance to sliding wear compared to pure aluminium and duralumin. Wear increases with increase in load and sliding velocity. Delamination and abrasion are the dominating types of wear observed. Keywords: Sliding Wear, Al2O3, MMNC, Duralumin, Delamination and Abrasion.
A Study on Mechanical and Tribological Properties of Magnesium Alloy AZ31 Rei...ijsrd.com
This work deals with fabricating or producing magnesium based metal matrix composite and then studying its mechanical and tribological properties such as microstructure, tensile strength, impact strength and wear behavior of produced test specimen. In the present study a modest attempt has been made to develop magnesium based MMCs with reinforcing material, with an objective to develop a conventional low cast method of producing MMCs and to obtain homogeneous dispersion of reinforced material. To achieve this objective stir casting technique has been adopted. An Alloy similar to commercially available composition of AZ31 and SiC, Al2O3 has been chosen as matrix and reinforcing material respectively. Experiment has been conducted by varying weight fraction of 3% SiC and 1% Al2O3 & 1% SiC and 3% Al2O3 in matrix metal. The result shown that tensile strength, impact strength, wear resistance is good in matrix metal as compared to used weight compositions of SiC and Al2O3 in the composites.
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.
The behavior of hybrid reinforced concrete after heat resistanceIJERA Editor
This study is trying to provide the behavior of concrete when additional fibers are added under the effect of
evaluated temperatures. Three types of polypropylene fibers are used with different length respectively 3 mm, 6
mm and 12 mm and two types of steel fibers are used of length respectively of 3cm and 5 cm. Hybrid specimens
of concrete are prepared by using two different combinations: 0.5% steel fibers in combination with 0.2%
polypropylene fibers by the volume of concrete; and 0.25% of steel fibers in combination with 0.1%
polypropylene fibers by the volume of concrete. The specimens were subject to different temperatures. An
electric furnace was used to heat the specimens up to 200 0C, 400 0C and 600 0C. The mass loss and compressive
strength were determined by using twelve different mixtures.
INVESTIGATION OF OPTIMIZED PROCESS PARAMETERS ON DENSIFICATION OF SAMARIUM CO...ijeljournal
The aim of this study is to investigate the effect of different process parameters on densification of
Samarium Cobalt 1:5 series (SmCo5) magnet by powder metallurgy technique. Different parameters for
sintering and heat treatment process such as particle size, load of press, sintering time and temperature,
furnace atmosphere and heating rate were tested in order to achieve the highest density. To analyze and
evaluate the microstructure and particle size of manufactured magnets scanning electron microscopy
(SEM) and X-ray diffraction (XRD) tests were conducted. Results of different tests showed that sintering
temperature as well as furnace atmosphere is among the most important parameters affecting on final
density of the samples. Investigations illustrated that highest density could be obtained with the sintering
of green bodies which made from initial particles with the size of 3 to 6 µm in vacuum condition at 1135˚C
for 30 min by rapid heating at the shortest time.
FRACTOGRAPHY OF CRYOGENIC CHILL CASTED ASTM A 494 M GRADE NICKEL ALLOY METAL ...IAEME Publication
ASTM A 494 M grade Ni–Garnet composites containing four different weight percentages 3%, 6%,9% and 12% of Garnet samples have been fabricated by using cryogenically cooled copper chill stir
casting method. Effects of volume percent of Garnet particles on tensile strength, and fracture surfacesof Nickel Garnet composites have been investigated. The highest tensile strength was achieved in the specimen containing 9 Wt. % garnet produced with 25 mm chill thickness which shows an increase of14% in comparison to the no chill cast reinforced alloy. Microscopic investigations of fracture surfacesrevealed that fracture in a brittle manner with little or no necking happening. By increasing garnetcontent and chill thickness, the composites fracture goes in a more severely brittle manner. The fracturebehavior of the composites was altered significantly by the presence of garnet particles and the crack
propagation through the matrix and the reinforcing particle clusters resulted in the final fracture.
Micro Structure Amd Mechanical Properties of Nanoparticulate Wc/Al Metal Matr...IJRES Journal
The addition of reinforcement definitely changes mechanical behaviour of metal matrix composites (MMCs). Hence the objective of the work is to study the effect of nano WC particle content on the mechanical behaviour of Al alloy reinforced composites was studied by using optical microscopy, mechanical properties measurements and scanning electron microscope. The hardness, ultimate tensile strength, compression strength and young's modulus were found higher than those of control alloy. The dislocations which serve as heterogeneous nucleation sites for strengthening precipitates during subsequent solidification compared to control alloy. Higher density of dislocations and higher density of intermediate precipitates was observed.
Energy Demand Analysis of Telecom Towers of Nepal with Strategic Scenario Dev...IJRES Journal
Telecom towers, technically known as BTS (Base Transceiver Stations) are the most energy intensive part of cellular network architecture and contribute up to 60 to 80% of total cellular power consumption and varies in response to the real traffic demand throughout the day and night. But, thelack of grid availability highlightsa potential barrier to telecom industry growth in Nepal. Nepal has approximately 5,222 telecom towers of which about 22% do operate on diesel generators (DGs) while the remaining by grid electricity with some shares of renewable energy technologies (RETs: solar and/or wind). Despite the large carbon imprint, the uncertainty in power availability has compelled telecom operators to use DGs to ensure continuous supply of power for the better network availability, which translates huge operating costs along with adverse environmental impact. So, it becomes an imperative solution for telecom operators to evaluate all alternatives in order to increase network reliability with reduced energy cost. This study report intentionally focus on current energy consumptionof such telecom towers and forecast thefuture energydemand with reference to growing subscriber trend up to 2025 using LEAP (Long Range Energy Alternative Planning System)withBusiness As Usual (BAU) scenario. A clean energy technology (CET) scenario with possible RET options is also developed and compared with base case scenario through some policy mechanics on behalf of environmental benefits and sustainable cellular communication. Furthermore, this study concludes a potential energy cum cost saving with RET adoption with basic cost economics analysis.
Interpreting Health Status Of Indian Population Using Phase Angle As Health P...IJRES Journal
Bio Electrical Impedance Analyser is a simple Non-Invasive tool that is used for the Human body composition Analysis. It has been found that the basic principle of Human Body composition Analysis is the measurement of fat vs lean muscle tissue. And it is well known fact that biological tissues the path of least resistance. While Analysing the body composition through Bio Electrical Impedance Analyser body resistance and body reactance are taken into account. Phase Angle is directly calculated from resistance and reactance and Phase Angle is an important indicator of cellular health and integrity. This paper aims at discussing the significance of Phase Angle in Analysis of Human Body Composition and developing and validating prediction equation of Phase Angle at different frequencies.
Preparation and Investigation on Properties of Cryogenically Solidified Nano ...IJERA Editor
In the present work, AL-alloy containing 12% silicon (LM 13) matrix nano composites were fabricated in sand moulds by using copper end blocks of copper end chill thickness 10 &15 nm with cryogenic effect . The size of the reinforcement (NanoZro2) ranges from 50-80nm being added ranges from 3 to 15 wt % in steps of 3 wt % . Cryogenically solidified Nano Metal Matrix Composites were compressed by using hydraulic compression machine. Specimens were prepared according to ASTM standards and tested for their strength, hardness and fracture toughness. Micro structural studies of the fabricated Nano Composites indicate that there is uniform distributions of reinforcements in the matrix materials (LM 13). An increasing trend of hardness, UTS & fracture toughness has been observed. The best results have been obtained at 12 wt %. The results were further justified by comparing two copper end chill thickness 10 &15 mm. Finally the Volumetric Heat Capacity of the cryo-chill is identified as an important parameter which affects mechanical properties.
A Study on Mechanical Properties of Fly Ash and Alumina Reinforced Aluminium ...IOSR Journals
The results of an experimental investigation of the mechanical properties of fly ash and Alumina
reinforced aluminium alloy (LM25) composites samples, processed by stir casting route are reported in this
paper. Three sets of composites with constant weight fraction of fly ash (particle size of 3-100 μm) and
Al2O3(particle size of 150 μm) with different wt% were used. Composite samples have the reinforcement weight
fractions of constant 3% fly Ash and varying %wt of 5, 10 and 15% Al2O3 . The main mechanical properties
studied were the tensile strength,ductilityimpact strength & hardness. Unreinforced LM25 samples were also
tested for the same properties. It was found that the tensile strength & hardness of the aluminium alloy (Lm25)
composites increases with the increase in %wt of Al2O3 upto certain limit. in addition of more amount of
reinforcement the Tensile strength decrease due to poor wettability of the reinforced material with metal
aluminium matrix .And the charpy test shows decrease in impact load absorption with increase in %weight
reinforcement.The Microstructure study of the samples indicated near uniform distribution of the fly ash and
Al2O3 particles in the matrix. LM25 alloy is mainly used where good mechanical properties are required in
castings of a shape or dimensions requiring an alloy of excellent castability in order to achieve the desired
standard of soundness.The alloy is also used where resistance to corrosion is an important consideration
particularly where highstrength is also required.
DEVELOPMENT AND TRIBOLOGICAL CHARACTERIZATION OF DUAL PARTICLE AND TRIPLE PAR...ijmech
The this work the study on hardness and wear behaviour of dual particle and triple particle size Alumina (Al2O3) reinforced aluminium alloy based metal matrix composite (Al2O3-Al MMC) was carried out. AlMMCs were prepared using 10 vol% Al2O3 reinforcement into aluminium metal matrix and developed using stir casting process. Stir casting is a most suitable process for the production of particulate MMC in which the reinforcement is introduced in to the molten matrix material with simultaneous stirring. The reinforcement in the range of particle size with Dual particle and Triple particle at 10% olume fraction with range from coarse to fine size were used (210µ, 180µ, 80µ & 10µ).The hardness of the composite was
determined by Vickers hardness tester and Brinell Hardness Tester. Tensile strength was determined by Universal Testing Machine (UTM). The wear rate was found by pin-on-disc type wear testing machine with steel disc of 60HRC hardness in dry sliding condition. Wear test was conducted on all the samples
at speeds of 300,600 and 900 rpm by varying the load (2kg, 4kg, 6kg & 8kg) at a constant sliding distance of 55mm. The wear track studies were carried out by optical microscope .The test results showed that Dual particle composite and triple particle composite exhibited better hardness compared to as cast AL- 7075. Strength of Triple particle reinforced MMC was found to be higher than that of dual particle reinforced composite material. The wear resistance properties of dual particle MMC was higher compared to triple particle reinforced MMC. The secondary process will further enhances the wear resistance of the composite and also that heat treatment will promote the wear resistance.
Investigation of Mechanical Properties of Aluminium Based Metal Matrix Compos...IJERA Editor
Present study is focused on the fabrication of aluminium 6061 based metal matrix composites, Reinforced with
silicon carbide and Al2O3 by stir casting technique. The percentage of one reinforcement particulate is kept
constant and varying other and vice versa, namely typeI and typeII composites. The various mechanical tests like
tensile strength test, hardness test, wear test and Impact strength performed on the samples obtained by stir
casting technique for comparison purpose. The result indicated that the developed method is quite successful and
there is an increase in the value of tensile strength, hardness value and Impact strength of newly developed
composite having (SiC + Al2O3) particulates in comparison to the Aluminium.
Wear characteristics of pure aluminium, al alloy & al-alumina metal mtrix...eSAT Journals
Abstract In this report, an aluminium metal matrix was reinforced with 1.5 wt. % of Al2O3 nano particles using non-contact cavitation method to prepare the metal matrix nano composite. Microstructural examination conducted on the sample revealed a uniform distribution of alumina particulates. Sliding wear behavior of the as-cast MMNC was studied in dry condition, under different test conditions by varying the load and the sliding velocity, with an unlubricated Multiple Tribo Tester. It was found that sliding wear resistance improved considerably with the addition of alumina nano particles. Microscopic examinations of the worn out surfaces of pure Al, Al-alloy (duralumin) and MMNC reveal that the MMNC has greater resistance to sliding wear compared to pure aluminium and duralumin. Wear increases with increase in load and sliding velocity. Delamination and abrasion are the dominating types of wear observed. Keywords: Sliding Wear, Al2O3, MMNC, Duralumin, Delamination and Abrasion.
A Study on Mechanical and Tribological Properties of Magnesium Alloy AZ31 Rei...ijsrd.com
This work deals with fabricating or producing magnesium based metal matrix composite and then studying its mechanical and tribological properties such as microstructure, tensile strength, impact strength and wear behavior of produced test specimen. In the present study a modest attempt has been made to develop magnesium based MMCs with reinforcing material, with an objective to develop a conventional low cast method of producing MMCs and to obtain homogeneous dispersion of reinforced material. To achieve this objective stir casting technique has been adopted. An Alloy similar to commercially available composition of AZ31 and SiC, Al2O3 has been chosen as matrix and reinforcing material respectively. Experiment has been conducted by varying weight fraction of 3% SiC and 1% Al2O3 & 1% SiC and 3% Al2O3 in matrix metal. The result shown that tensile strength, impact strength, wear resistance is good in matrix metal as compared to used weight compositions of SiC and Al2O3 in the composites.
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.
The behavior of hybrid reinforced concrete after heat resistanceIJERA Editor
This study is trying to provide the behavior of concrete when additional fibers are added under the effect of
evaluated temperatures. Three types of polypropylene fibers are used with different length respectively 3 mm, 6
mm and 12 mm and two types of steel fibers are used of length respectively of 3cm and 5 cm. Hybrid specimens
of concrete are prepared by using two different combinations: 0.5% steel fibers in combination with 0.2%
polypropylene fibers by the volume of concrete; and 0.25% of steel fibers in combination with 0.1%
polypropylene fibers by the volume of concrete. The specimens were subject to different temperatures. An
electric furnace was used to heat the specimens up to 200 0C, 400 0C and 600 0C. The mass loss and compressive
strength were determined by using twelve different mixtures.
INVESTIGATION OF OPTIMIZED PROCESS PARAMETERS ON DENSIFICATION OF SAMARIUM CO...ijeljournal
The aim of this study is to investigate the effect of different process parameters on densification of
Samarium Cobalt 1:5 series (SmCo5) magnet by powder metallurgy technique. Different parameters for
sintering and heat treatment process such as particle size, load of press, sintering time and temperature,
furnace atmosphere and heating rate were tested in order to achieve the highest density. To analyze and
evaluate the microstructure and particle size of manufactured magnets scanning electron microscopy
(SEM) and X-ray diffraction (XRD) tests were conducted. Results of different tests showed that sintering
temperature as well as furnace atmosphere is among the most important parameters affecting on final
density of the samples. Investigations illustrated that highest density could be obtained with the sintering
of green bodies which made from initial particles with the size of 3 to 6 µm in vacuum condition at 1135˚C
for 30 min by rapid heating at the shortest time.
FRACTOGRAPHY OF CRYOGENIC CHILL CASTED ASTM A 494 M GRADE NICKEL ALLOY METAL ...IAEME Publication
ASTM A 494 M grade Ni–Garnet composites containing four different weight percentages 3%, 6%,9% and 12% of Garnet samples have been fabricated by using cryogenically cooled copper chill stir
casting method. Effects of volume percent of Garnet particles on tensile strength, and fracture surfacesof Nickel Garnet composites have been investigated. The highest tensile strength was achieved in the specimen containing 9 Wt. % garnet produced with 25 mm chill thickness which shows an increase of14% in comparison to the no chill cast reinforced alloy. Microscopic investigations of fracture surfacesrevealed that fracture in a brittle manner with little or no necking happening. By increasing garnetcontent and chill thickness, the composites fracture goes in a more severely brittle manner. The fracturebehavior of the composites was altered significantly by the presence of garnet particles and the crack
propagation through the matrix and the reinforcing particle clusters resulted in the final fracture.
Micro Structure Amd Mechanical Properties of Nanoparticulate Wc/Al Metal Matr...IJRES Journal
The addition of reinforcement definitely changes mechanical behaviour of metal matrix composites (MMCs). Hence the objective of the work is to study the effect of nano WC particle content on the mechanical behaviour of Al alloy reinforced composites was studied by using optical microscopy, mechanical properties measurements and scanning electron microscope. The hardness, ultimate tensile strength, compression strength and young's modulus were found higher than those of control alloy. The dislocations which serve as heterogeneous nucleation sites for strengthening precipitates during subsequent solidification compared to control alloy. Higher density of dislocations and higher density of intermediate precipitates was observed.
Energy Demand Analysis of Telecom Towers of Nepal with Strategic Scenario Dev...IJRES Journal
Telecom towers, technically known as BTS (Base Transceiver Stations) are the most energy intensive part of cellular network architecture and contribute up to 60 to 80% of total cellular power consumption and varies in response to the real traffic demand throughout the day and night. But, thelack of grid availability highlightsa potential barrier to telecom industry growth in Nepal. Nepal has approximately 5,222 telecom towers of which about 22% do operate on diesel generators (DGs) while the remaining by grid electricity with some shares of renewable energy technologies (RETs: solar and/or wind). Despite the large carbon imprint, the uncertainty in power availability has compelled telecom operators to use DGs to ensure continuous supply of power for the better network availability, which translates huge operating costs along with adverse environmental impact. So, it becomes an imperative solution for telecom operators to evaluate all alternatives in order to increase network reliability with reduced energy cost. This study report intentionally focus on current energy consumptionof such telecom towers and forecast thefuture energydemand with reference to growing subscriber trend up to 2025 using LEAP (Long Range Energy Alternative Planning System)withBusiness As Usual (BAU) scenario. A clean energy technology (CET) scenario with possible RET options is also developed and compared with base case scenario through some policy mechanics on behalf of environmental benefits and sustainable cellular communication. Furthermore, this study concludes a potential energy cum cost saving with RET adoption with basic cost economics analysis.
Interpreting Health Status Of Indian Population Using Phase Angle As Health P...IJRES Journal
Bio Electrical Impedance Analyser is a simple Non-Invasive tool that is used for the Human body composition Analysis. It has been found that the basic principle of Human Body composition Analysis is the measurement of fat vs lean muscle tissue. And it is well known fact that biological tissues the path of least resistance. While Analysing the body composition through Bio Electrical Impedance Analyser body resistance and body reactance are taken into account. Phase Angle is directly calculated from resistance and reactance and Phase Angle is an important indicator of cellular health and integrity. This paper aims at discussing the significance of Phase Angle in Analysis of Human Body Composition and developing and validating prediction equation of Phase Angle at different frequencies.
The research of technology for automatically cutting Patterns' edge with edge...IJRES Journal
With the designed optical systems, machine vision systems, laser cutting machine body constitute automatic boundary cutting machine vision systems with the clothing patterns. The use of digital image processing technologies, such as filtering, edge detecting and edge tracking algorithms ,has effectively extracted continuous contour of patterns which will significantly distinguish the foreground from background as cutting information of the target edge called cutting vectors, and thus cutting vectors control the laser cutting equipment SPIN1006 to precisely cut the target pattern. This technology can achieve the automatic boundary cutting of the full version of alien costumes’ pattern.
The implementation of BPJS health program At public health center martapura i...IJRES Journal
Improving the quality of health services at the primary level is very important to reduce the burden of services which will be covered hospital when the BPJS program applied. The aimed of this study is to describe the implementation of the program of BPJS in Public Health Center (PHC) Martapura. This study was a qualitative research with case study design. The informants are the head of PHC and manager program were taken by purposive sampling. Data were collected through interviews using in-depth interview guide. Result of this study was since the enactment BPJS January 1, 2014, Banjar Regency Health Office only once to disseminate ie in March 2014. This makes the health center to get the barriers in the field of the sustainability of the information obtained from the health department with the information captured on the official website BPJS. Another barriers was the disbursement claims that have not been implemented which should have been right to health centers for services provided. Support from the health department and BPJS needed to inform about the national health insurance program regularly to health centers so that health centers do not confusion in implementing the program.
An Enhanced P2P Architecture for Dispersed Service DiscoveryIJRES Journal
Service discovery is a critical issue in Service Oriented Computing (SOC).Service discovery protocols used to detect and discover services offered by the nodes in the network. It must be scalable, reliable and robust service discovery mechanism. In traditional discovery mechanism uses decentralized service discovery approach named as chord4s.This method suffer from some problems such as scalability, node failure and efficient query routing. This paper addresses additional functionalities of chord4s protocol. In this paper data availability in chord4s protocol is improved by distributing functionally equivalent services to different successor nodes. If one node fails service consumer gets equivalent services from the other successor nodes. In this paper efficient query routing can be improved by getting multiple services with single query. Quality of service also improved by qos aware service discovery methods. Semantic information of services is integrated in order to increase flexibility, accuracy of service discovery.
Application and development of numerical simulation technology in CastingIJRES Journal
The basic theory of the numerical simulation of casting and casting process, also the development and application of numerical calculations in the foundry engineering. Outlined the main feature of the softwares of numerical simulation of casting both here and abroad , analyzes the softwares played a significant role in actual casting and research, meanwhile pointed out the problems and development direction of the casting simulation softwares. Description reasonable use of simulation software can improve the quality of castings, Optimize the casting process, shorten the duration of the casting design and reduce costs.
Criterion of functional fullness in many-valued logicIJRES Journal
Using Slupecki’s criterion of functional fullness we give very simple proof of Jablonskij’s criterion. Then using
Jablonskij’s criterion we get criterion of minimal closed sets: a subset of functions of Pk ( k2 ) is full in k P , if
it contains a non-fictitious two-ary function taking all values and functions of minimal closed sets of some type.
The criterion is very useful. In particular, Slupecki’s criterion uses 27 functions, Jablonskij’s criterion uses 21
functions, the criterion of minimal closed sets uses 3 functions in 3-valued logic. The criteria use 255, 231, 6
functions in 4-valued logic respectively and 3125, 3005, 10 functions in 5-valued logic.
Comparison of the Performances of Two Commercial Membranes in Demineralizatio...IJRES Journal
In this work, comparison of the performances of two commercial membranes in demineralization of drinking water of M’rirt city (conductivity 2140 μS/cm) by nanofiltration in continuous mode was carried out. The pilot used (supplied by the French Company TIA, Techniques Industrilles Appliquées) is an industrial nanofiltration pilot plant having two modules equipped with various spiral commercial membranes with an area of 7.6 m2. Two configurations were tested: simple pass and supplied batch configuration. The water parameters were followed as a function of the running conditions (time, pressure) in order to follow the behaviour of the membranes tested.
Nonlinear Algebraic Systems with Three Unknown VariablesIJRES Journal
Work is devoted to the study of nonlinear algebraic systems with three unknowns and is a
continuation of the author's research in this area. Previously, for nonlinear algebraic of system of equations
was built analog determinant of Kramer and it is given a necessary and sufficient condition for the existence of
solutions of nonlinear algebraic systems with a complex dependence on the variables. For two-parameter
systems in the abstract case, it is obtained the results to determine the conditions for finding the number of
solutions.
In this paper describes the method of determining the conditions on the coefficients of algebraic systems to
establish the number of solutions of the algebraic system of equations, when an unknowns part in the system as
polynomials in any finite degree. This method can be applied to other algebraic systems with more than
three unknown variables.
Synergistic Effect of Halide Ions on the Corrosion Inhibition of Mild Steel i...IJRES Journal
The inhibition effect of alkyl substituted piperdin-4-one with thiosemicarbazones on mild steel
corrosion in 1N sulphuric acid solution was studied by weight loss method and electrochemical techniques. The
influence of halides viz., KCl, KBr and KI on the corrosion inhibition of thiosemicarbazones were also
investigated. Results show that alkyl substituted piperidin-4-one with thiosemicarbazones alone provided
satisfactory inhibition on the corrosion of mild steel and it was also found that the inhibition efficiency increased
synergistically in the presence of halide ions. The synergistic effect of halide ions was found to follow the order:
KI > KBr > KCl. The inhibitor reduced the corrosion rate through adsorption.
Study and evaluation for different types of Sudanese crude oil propertiesIJRES Journal
Sudanese crude oil is regarded as one of the sweet types of crude in the world, Sulphur containing
compounds are un desirable in petroleum because they de activate the catalyst during the refining processes and
are the main source of acid rains and environmental pollution.(Mark Cullen 2001),Since it contains considerable
amount of salts and acids, it negatively impact the production facilities and transportation lines with corrosive
materials. However it suffers other problems in flow properties represented by the high viscosity and high
percentage of wax. Samples were collected after the initial and final treatment at CPF, and tested for
physical and chemical properties.wax content is in the range 23-31 weight % while asphalting content is about
0.1 weight% . Resin content is 13-7 weight % and deposits are 0.01 weight%. The carbon number distribution in
the crude is in the range 7-35 carbon atoms. The pour point vary between 39°C-42°C and the boiling point is in
the range 70 °C - 533 °C.
Design of the floating-type memristor emulator and its circuit implementationIJRES Journal
Memristor is a kind of nonlinear resistance with memory ability. The resistance of the memristor
changes depending on the charge quantity or the magnetic flux passing through it. As a basic two-terminal
device, the memristor should be connected with other electronic devices in any form and not limited to the
grounding-type. In this paper, a new memristor emulator is proposed based on HP memristor model and then a
floating-type memristor emulator is designed. Finally, the corroding physical circuits are built to verify the
correctness of the design.
PID Compensator Control Scheme of Synchronous Buck DC-DC Converter with ZVS L...IJRES Journal
This paper deals with PID compensator control of Synchronous Rectifier (SR) Buck Converter to improve its conversion efficiency under different load conditions with the help of a Zero Voltage Switching(ZVS)Logic Circuit. Since the freewheeling diode is replaced by a high frequency switch MOSFET in this buck configuration, the SR control technique itself will be sufficient under heavy load condition to attain better normal mode performance. However, this technique does not hold well in light load condition, due to increased switching losses. A newPID compensator control techniqueis introduced in the paper will enable synchronous buck converter to realize ZVS, while feeding light load. This is also cost effective and highly efficient simple control method without use of extra auxiliary switches and RLC components. This control technique also proved to be efficient under input voltage variations. Simulation is done for proving stabilization provided by the PID compensator with the help of ZVS logic circuit for synchronous rectifier (SR) buck converter in MATLAB Simulink.
A Case Study on Academic Services Application Using Agile Methodology for Mob...IJRES Journal
Recently, Mobile Cloud Computing reveals many modern development areas in the Information
Technology industry. Several software engineering frameworks and methodologies have been developed to
provide solutions for deploying cloud computing resources on mobile application development. Agile
methodology is one of the most commonly used methodologies in the field. This paper presents the MCCAS a
Web and Mobile application that provide feature for the Palestinian higher education/academic institutions. An
Agile methodology was used in the development of the MCCAS but in parallel with emphasis on Cloud
computing resources deployment. Also many related issues is discussed such as how software engineering
modern methodologies (advances) influenced the development process.
Status of Heavy metal pollution in Mithi river: Then and NowIJRES Journal
The Mithi River runs through the heart of suburban Mumbai. Its path of flow has been severely
damaged due to industrialization and urbanization. The quality of water has been deteriorating ever since. The
Municipal and industrial effluents are discharged in unchecked amounts. The municipal discharge comprises
untreated domestic and sewage wastes whereas the industries are majorly discharge chemicals and other toxic
effluents which are responsible in increasing the metal load of the river. In the current study, the water is
analysed for heavy metals- Copper, Cadmium, Chromium, Lead and Nickel. It also includes a brief
understanding on the fluctuations that have occurred in the heavy metal pollution, through the compilation of
studies carried out in the area previously.
Distillery Wastewater Decontamination by the Fenton Advanced Oxidation MethodIJRES Journal
This study evaluated the effect of Fenton advanced oxidation process on the treatment of an industrial wastewater (distillery). The comparison of the effects of Fe2+ loadings, H2O2 dosages (2%(v/v)and 4%(v/v)), reaction temperature and reaction time, established optimum efficiency in terms of BOD and COD reductions. The best operating conditions for the treatment of the distillery wastewater containing 43.85 mg/L BOD concentration and 274.28 mg/L COD concentration in the raw effluent was 2% H2O2 dosage at constant loadings of Fe2+ (1.5 g), 80 oC pretreatment temperature, and 1 h reaction time. At this optimized condition, the BOD content reduced to about 35 mg/L (about 21% removal) and COD content reduced to about 53 mg/L (about 81% removal). There was a complete removal of the initial colour present in the wastewater after the treatment process. The process proved the ability to effectively reduce the COD content which when high in industrial wastewaters can lead to serious impacts to the environment.
Automated airfield controller system for avoiding air crashes in runwayIJRES Journal
This work is an attempt to develop an advanced technology in airport control systems. As the existing system is manually operated, it is difficult to find solutions for some unexpected problems, for example: fire accident, ice, rain, fog and snow which may occur on the runway during the landing of the flight, which leads to air crashes in the runway . To take protective measures, introducing an automatic system to detect whether the runway is safe before landing the flight and this system also takes protective measures until the flight completely stops in the Airport. GPS (Global Positioning System) is used for inform the user to about exact location of the landing zone in the runway. Stepper motor is used as barrier system to control entry for vehicles and human. Zigbee transceiver is used as wireless communication protocol between aircraft and airfield controller system.
Optimizing Shock Models In The Study Of Deteriorating SystemsIJRES Journal
This research is to make a detailed study of deteriorating systems using the shock model approach. Cumulative damage models in which the damages due to various shocks accumulate and the system failure is viewed as the first passage problem of the cumulative damage process past a threshold are analyzed. We consider the cumulative damage models in a totally different perspective by considering the optimal stopping in an accumulative damage model. The stopping rule is that the cumulative damage may surpass a prescribed threshold level only with a small probability but should approach the threshold as precise as possible. Finally we analyze shock models for which the system failure is based on the frequency of shocks rather than the cumulative damage caused by them. Numerical examples and discussions are provided to illustrate the results.
The Drill Geometry Influence on PCB Drilling PerformanceIJRES Journal
To adapt to the rapid development of PCBs, a high-property drill is desired. An applicable way is demonstrated by a design method based on analysis of drill structure, cutting force experiment , cutter wear observation to improve the drilling performance.Finally the drill wear is well improved by web thinning and chip dividing groove grinding.
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
Dry Sliding Wear Behaviour of Rheocat Al-5.7Si-2Cu-0.3Mg AlloyDr. Manal Abdullatif
In this study, the effect of improved microstructure of Al-5.7Si-2Cu-0.3Mg alloys by using semisolid process on hardness and dry sliding wear behaviour were investigated. The microstructures of conventional cast alloy were totally dendritic, while in rheocasting the dendrit-ic transfer to fine globular microstructures after using cooling slope casting. Tribological tests were carried out by using a pin-on-disc apparatus in dry sliding conditions. Wear tests were at low sliding speed 1ms-1 ,applied load at 50N and three different sliding distance (i.e., 1.8Km, 5.4Km and 9Km) respectively. An optical microscope and a scanning electron microscope were used to examine the micro-structure and to understand the wear mechanism on the worn surface of both samples. The results showed that, the wear resistance of rheocast alloy was improved and higher than that those produce by conventional casting. The volume loss of rheocast alloy show reduc-tion more than 18% at 1.8Km and 10% at 9Km compared to as-cast alloy. Moderate wear regimes were appeared in both alloys, accord-ing to the range of wear rate. The friction coefficient had increased due to increase in the contact point between pin and disc materials. The dominant wear mechanism for conventional and rheocasting alloys was adhesion wear and abrasive wear respectively.
Study on Processing and Mechanical Properties of nano SiCp reinforced AA7075theijes
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The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Uniform particle distribution by a newer method in composite metal of Al/SiCIOSR Journals
Abstract: Preparation of composites of metal with ceramic particle reinforced through the casting process
is not uniform because of poor wet ability. The major difficulty is to get a uniform distribution of
reinforcement especially in higher volume fractions. An innovative method of producing cast composites is
tried in present study to overcome this problem we need homogeneity of matrix. The method involves multi
axis rotation of liquid aluminum and silicon carbide particulates packed in a steel pipe inside a rotating drum.
Up to 65 % volume of the metal (aluminum)is incorporated by SIC by this technique. Physical Properties
like hardness, micro hardness, densities and microstructures have been studied. The distribution of
particles as well the mechanical properties are better as compared to that of stir cast composites with similar
volume fraction of silicon carbide reinforcement. The composite with 65-volume percentage of silicon carbide
of particulates showed a Rockwell Hardness value of 67Rb.In few locations the microstructure showed a
non-uniform distribution which can be neglected . There were segregation of silicon carbide particles at a
particular location and the hardness obtained there was much higher. The particle distribution is a result
of the combined influence of random mixing of particles and liquid aluminum and the solidification pattern
obtained.
Key word: Multi axis rotation, microstructure, MMC, Al- SIC matrix
Wear characteristics of pure aluminium, al alloy & al-alumina metal mtrix...eSAT Journals
Abstract In this report, the aluminium metal matrix was reinforced with 1.5 wt. % of Al2O3 nano particles using non-contact cavitation method to prepare the metal matrix nano composite. Microstructural examination conducted on the samples revealed a uniform distribution of alumina particulates. Sliding wear behavior of the as-cast MMNC was studied in dry condition, under different test conditions by varying the load and the sliding velocity, with an unlubricated Multiple Tribo Tester. It was found that resistance to sliding wear improved considerably with the addition of alumina nano particles. Microscopic examinations of the worn out surfaces of pure Al, Al-alloy (duralumin) and MMNC reveal that the MMNC has greater resistance to sliding wear compared to pure aluminium and duralumin. Wear increases with increase in load and sliding velocity. Wear is more when load and speed are increased in steps. Delamination and abrasion are the dominating types of wear observed. Keywords: Sliding Wear, Al2O3, MMNC, Duralumin, Delamination and Abrasion.
Wear characteristics of pure aluminium, al alloy & al-alumina metal mtrix...eSAT Journals
Abstract In this report, the aluminium metal matrix was reinforced with 1.5 wt. % of alumina nano particles using non-contact cavitation method to prepare the metal matrix nano composite. Microstructural investigation was conducted on the worn out samples. It showed uniform distribution of alumina particles in the matrix. Sliding wear behavior of the as-cast MMNC was studied in dry condition, under different test conditions by varying the load (constant and step loads) and the sliding speed (constant and step speeds) using a Multiple Tribo Tester. It was found that resistance to sliding wear improved considerably with the addition of alumina nano particles. FESEM images of the worn out surfaces of pure Al, Al-alloy (duralumin) and MMNC reveal that the MMNC has greater resistance to sliding wear compared to pure aluminium and duralumin. Wear rate increases with increase in load and sliding velocity. Wear rate is more when load and speed are increased in steps. Delamination and abrasion are the dominating types of wear observed. Keywords: Wear rate, Al2O3, MMNC, Duralumin. Coefficient of friction.
Structural Stability of Nano-Crystalline Aluminum-Glass CompositesIOSRJAP
Effects of particle size of the material in nanometer on solid state, structural properties AluminumGlass based samples are reported in this study. The particle size of 25µm was used for both Aluminum and Glass powders respectively. The samples were prepared in powdered form of various Al-Glass proportions. The weight of Aluminum ranges between 20 – 60 percent in the composites. Results showed from X-ray diffraction analyses that Aluminum addition and the determined particle size greatly influence the structural stability of the samples. It was revealed that samples were structurally stable in the range of Aluminum composition and the observed size of crystals, measured Width at Middle of Maximum Height and structural parameters were found in nanometers. The Al-Glass materials were noted to crystallize with FCC and BCC lattice structures.
Effect of Fly Ash Particles on the Mechanical Properties of Zn-22%Al Alloy vi...IOSR Journals
In the present investigation, a Zn-22%Al alloy is used as the matrix material and fly ash as the filler material. The composite is produced using powder metallurgy techniques. The fly ash is added in 2%, 4%, and 6% by wt% to the sintering metal. The composite is tested for hardness, density and tensile strength test. Microstructure examination is done using a high resolution optical microscope to obtain the distribution of fly ash in the Zn-Al matrix. Test results indicate that as fly ash content is increased, there is a considerable increase in hardness and tensile strength but decrease in density.
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.
Evaluation of thermo-Mechanical Behaviour of Clay- Silica Sand Blends For Fir...IJRES Journal
In this study, the thermo-mechanical behavior of clay-silica sand blends was evaluated with a view to establishing its suitability for fire-clay bricks production.The study involved Standard bricks using proportional clay mixtures (0-100%) with 10% increment of silica sand. Results obtained indicate that addition of silica sand to Makurdi clay improved foundry properties of cold crushing strength, bulk density, shrinkage, apparent porosity, thermal shock resistance, permeability and refractoriness Based on these results it is concluded that Makurdi clay is suitable for fire clay bricks production if blend with silica sand (SiO2).
Similar to Alumina-Based Composites Reinforced With Ductile Particles (20)
Exploratory study on the use of crushed cockle shell as partial sand replacem...IJRES Journal
The increasing demand for natural river sand supply for the use in construction industry along
with the issue of environmental problem posed by the dumping of cockle shell, a by-product from cockle
business have initiated research towards producing a more environmental friendly concrete. This research
explores the potential use of cockle shell as partial sand replacement in concrete production. Cockle shell used
in this experimental work were crushed to smaller size almost similar to sand before mixed in concrete. A total
of six concrete mixtures were prepared with varying the percentages of cockle shell viz. 0%, 5%, 10%, 15%,
20% and 25%. All the specimens were subjected to continuous water curing. The compressive strength test was
conducted at 28 days in accordance to BS EN 12390. Finding shows that integration of suitable content of
crushed cockle shell of 10% as partial sand replacement able to enhance the compressive strength of concrete.
Adopting crushed cockle shell as partial sand replacement in concrete would reduce natural river sand
consumption as well as reducing the amount of cockle shell disposed as waste.
Congenital Malaria: Correlation of Umbilical Cord Plasmodium falciparum Paras...IJRES Journal
The vertical (trans-placental) transmission of the parasite Plasmodium falciparum from
pregnant mother to fetus during gestational period was investigated in a clinical research involving 43 full term
pregnant women in selected Hospitals in Jimeta Yola, Adamawa State Nigeria. During the observational study,
parasitemia was determined by light microscopic examination of umbilical and maternal peripheral blood film
for the presence of the trophozoites of Plasmodium falciparum. Correlational analysis was then carried on the
result obtained at p<0.05.><0.05) was established between maternal peripheral blood and umbilical cord
blood parasitemia with Pearson’s correlation coefficient of 0.762. Thus, in a malaria endemic area like Yola,
Adamawa State, Nigeria, with a stable transmission of parasite, there is a high probability of vertical
transmission of Plasmodium falciparum parasite from mother to fetus during gestation that can be followed by
the presentation of the symptoms of malaria by the newborn and other malaria related complications. Families
are advised to consistently sleep under appropriately treated insecticide mosquito net to avoid mosquito bite and
subsequent infestation.
Review: Nonlinear Techniques for Analysis of Heart Rate VariabilityIJRES Journal
Heart rate variability (HRV) is a measure of the balance between sympathetic mediators of heart
rate that is the effect of epinephrine and norepinephrine released from sympathetic nerve fibres acting on the
sino-atrial and atrio-ventricular nodes which increase the rate of cardiac contraction and facilitate conduction at
the atrio-ventricular node and parasympathetic mediators of heart rate that is the influence of acetylcholine
released by the parasympathetic nerve fibres acting on the sino-atrial and atrio-ventricular nodes leading to a
decrease in the heart rate and a slowing of conduction at the atrio-ventricular node. Sympathetic mediators
appear to exert their influence over longer time periods and are reflected in the low frequency power(LFP) of
the HRV spectrum (between 0.04Hz and 0.15 Hz).Vagal mediators exert their influence more quickly on the
heart and principally affect the high frequency power (HFP) of the HRV spectrum (between 0.15Hz and 0.4
Hz). Thus at any point in time the LFP:HFP ratio is a proxy for the sympatho- vagal balance. Thus HRV is a
valuable tool to investigate the sympathetic and parasympathetic function of the autonomic nervous system.
Study of HRV enhance our understanding of physiological phenomenon, the actions of medications and disease
mechanisms but large scale prospective studies are needed to determine the sensitivity, specificity and predictive
values of heart rate variability regarding death or morbidity in cardiac and non-cardiac patients. This paper
presents the linear and nonlinear to analysis the HRV.
Dynamic Modeling for Gas Phase Propylene Copolymerization in a Fluidized Bed ...IJRES Journal
A two-phase model is proposed for describing the dynamics of a fluidized bed reactor used for
polypropylene production. In the proposed model, the fluidized bed is divided into an emulsion and bubble
phase where the flow of gas is considered to be plug flow through the bubbles and perfectly mixed through the
emulsion phase. Similar previous models, consider the reaction in the emulsion phase only. In this work the
contribution of reaction in the bubble phase is considered and its effect on the overall polypropylene production
is investigated the kinetic model is combined with hydrodynamic model in order to develop a comprehensive
model for gas-phase propylene copolymerization reactor. Simulation profiles of the proposed model were
compared with those of well mixed model for the emulsion phase temperature. The simulated temperature
profile showed a lower rate of change compared to the previously reported models due to lower polymerization
rate. Model simulation showed that about 13% of the produced polymer comes from the bubble phase and this
considerable amount of polymerization in the bubbles should not be neglected in any modeling attempt.
A Short Report on Different Wavelets and Their StructuresIJRES Journal
This article consists of basics of wavelet analysis required for understanding of and use of wavelet
theory. In this article we briefly discuss about HAAR wavelet transform their space and structures.
Wear Analysis on Cylindrical Cam with Flexible RodIJRES Journal
Firstly, the kinetic equation of spatial cylindrical cam with flexible rod has been established. Then, an
accurate cylindrical cam mechanism model has been established based on the spatial modeling software
Solidworks. The dynamic effect of flexible rod on mechanical system was studied in detail based on the
mechanical system dynamics analytical software Adams, and Archard wear model is used to predict the wear of
the cam. We used Ansys to create finite element model of the cam link, extracted the first five order mode to
export into Adams. The simulation results show that the dynamic characteristics of spatial cylindrical cam
mechanical system with flexible rod is closed to ideal mechanism. During the cam rotate one cycle, the collision
in the linkage with a clearance occurs in some special location, others still keep a continuous contact, and the
prediction of wear loss is smaller than rigid body.
DDOS Attacks-A Stealthy Way of Implementation and DetectionIJRES Journal
Cloud Computing is a new paradigm provides various host service [paas, saas, Iaas over the internet.
According to a self-service,on-demand and pay as you use business model,the customers will obtain the cloud
resources and services.It is a virtual shared service.Cloud Computing has three basic abstraction layers System
layer(Virtual Machine abstraction of a server),Platform layer(A virtualized operating system, database and
webserver of a server and Application layer(It includes Web Applications).Denial of Service attack is an attempt
to make a machine or network resource unavailable to the intended user. In DOS a user or organization is
deprived of the services of a resource they would normally expect to have.A Successful DOS attack is a highly
noticeable event impacting the entire online user base.DOS attack is found by First Mathematical Metrical
Method (Rate Controlling,Timing Window,Worst Case and Pattern Matching)DOS attack not only affect the
Quality of the service and also affect the performance of the server. DDOS attacks are launched from Botnet-A
large Cluster of Connected device(cellphone,pc or router) infected with malware that allow remote control by an
attacker. Intruder using SIPDAS in DDOS to perform attack.SIPDAS attack strategies are detected using Heap
Space Monitoring Algorithm.
An improved fading Kalman filter in the application of BDS dynamic positioningIJRES Journal
Aiming at the poor dynamic performance and low navigation precision of traditional fading
Kalman filter in BDS dynamic positioning, an improved fading Kalman filter based on fading factor vector is
proposed. The fading factor is extended to a fading factor vector, and each element of the vector corresponds to
each state component. Based on the difference between the actual observed quantity and the predicted one, the
value of the vector is changed automatically. The memory length of different channel is changed in real time
according to the dynamic property of the corresponding state component. The actual observation data of BDS is
used to test the algorithm. The experimental results show that compared with the traditional fading Kalman filter
and the method of the third references, the positioning precision of the algorithm is improved by 46.3% and
23.6% respectively.
Positioning Error Analysis and Compensation of Differential Precision WorkbenchIJRES Journal
Positioning error is a widely problem exists in mechanism, the important factors affecting machining
precision. In order to reduce the error caused by positioning problem processing, based on the differential
workbench as the research object, using the method of theoretical analysis and experimental verification, the
analysis of positioning error mechanism and source of complete differential precision workbench error
compensation, improve the accuracy of the device, provides a method for the application of modern machine
tools. table.
The Low-Temperature Radiant Floor Heating System Design and Experimental Stud...IJRES Journal
In order to analyze the temperature distribution of the low-temperature radiant floor heating system
that uses the condensing wall-hung boiler as the heat source, the heating system is designed according to a typical
house facing south in Shanghai. The experiments are carried out to study the effects of the supply water
temperature on the thermal comfort of the system. Eventually, the supply water temperature that makes people in
the room feel more comfortable is obtained. The result shows that in the condition of that the outside temperature
is 8~15℃ and the relative humidity is 30~70%RH, the temperature distribution in the room is from high to low
when the height is from bottom to top. The floor surface temperature is highest, but its uniformity is very poor.
When the heating system reaches the steady state, the air temperature of the room is uniform. When the supply
water temperature is 63℃ The room is relatively comfortable at the above experimental condition.
Experimental study on critical closing pressure of mudstone fractured reservoirsIJRES Journal
In the process of oil and gas exploitation of mudstone-fractured reservoir in Daqing oilfield, the
permeability of fracture is easily affected by the influence of stress change, which is shown by the sensitivity of
the permeability to the stress. With the extension of time mining in the fractured mudstone reservoir, fracture
stress sensitivity is obvious in vast decline of production and great influence on reduced yields. In order to
reasonably determine the way of developing method, working system and the exploitation rate of the reservoir,
correspondingly protecting reservoir productivity, improve ultimate recovery. On the basis of the previous
research on the stress sensitivity of fractured mudstone, this essay studied the critical closing pressure of the
simulated underground fractured mudstone under the laboratory condition.
Correlation Analysis of Tool Wear and Cutting Sound SignalIJRES Journal
With the classic signal analysis and processing method, the cutting of the audio signal in time
domain and frequency domain analysis. We reached the following conclusions: in the time domain analysis,
cutting audio signals mean and the variance associated with tool wear state change occurred did not change
significantly, and tool wear is not high degree of correlation, and the mean-square value of the audio signal
changes in the size and tool wear the state has a good relationship.
Reduce Resources for Privacy in Mobile Cloud Computing Using Blowfish and DSA...IJRES Journal
Mobile cloud computing in light of the increasing popularity among users of mobile smart
technology which is the next indispensable that enables users to take advantage of the storage cloud computing
services. However, mobile cloud computing, the migration of information on the cloud is reliable their privacy
and security issues. Moreover, mobile cloud computing has limitations in resources such as power energy,
processor, Memory and storage. In this paper, we propose a solution to the problem of privacy with saving and
reducing resources power energy, processor and Memory. This is done through data encryption in the mobile
cloud computing by symmetric algorithm and sent to the private cloud and then the data is encrypted again and
sent to the public cloud through Asymmetric algorithm. The experimental results showed after a comparison
between encryption algorithms less time and less time to decryption are as follows: Blowfish algorithm for
symmetric and the DSA algorithm for Asymmetric. The analysis results showed a significant improvement in
reducing the resources in the period of time and power energy consumption and processor.
Resistance of Dryland Rice to Stem Borer (Scirpophaga incertulas Wlk.) Using ...IJRES Journal
Rice stem borer is one of the important pests that attack plants so as to reduce production. One way
to control pests is to use organic fertilizers that make the plant stronger and healthier. This study was conducted
to determine the effects of organic fertilizers with various doses without the use of pesticides in controlling stem
borer, Scirpophaga incertulas. Methods using split-split plot design which consists of two levels of the whole
plot factor (solid and liquid organic fertilizers), two levels of the subplot factor (conventional and industry,
Tiens and Mitraflora), and four levels of the sub-subplot factor of conventional and industry (5, 10, 15, 20
tonnes/ha), and one level of the sub-subplot factor of Tiens and Mitraflora (each 2 ml/l). Based on the results
Statistical analysis there were no significant differences among treatments and this shows that the use of organic
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Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
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Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
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Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Alumina-Based Composites Reinforced With Ductile Particles
1. International Journal of Research in Engineering and Science (IJRES)
ISSN (Online): 2320-9364, ISSN (Print): 2320-9356
www.ijres.org Volume 2 Issue 6 ǁ June. 2014 ǁ PP.60-64
www.ijres.org 60 | Page
Alumina-Based Composites Reinforced With Ductile Particles
J. Osorio-Ramos1
, E. Refugio-García1
, E. Terres-Rojas2
, J.G. Miranda-
Hernández3
J.A. Rodríguez-García4
And E. Rocha-Rangel4
1
Departamento de Materiales, Universidad Autónoma Metropolitana, 02200, México
2
Laboratorio de Microscopía Electrónica de Ultra Alta Resolución, IMP, 07730, México
3
Universidad Autónoma del Estado de México (UAEM-Valle de México), 54500, México
4
Universidad Politécnica de Victoria, 87138, México
ABSTRACT: Al2O3/Metal composite ceramics were fabricated by the use of mechanical milling and
pressureless sintering. Al2O3 + 10 vol.% of La, Mn, Si or Y were mixed and milled during 12 h at 300 rpm in a
horizontal mill, then with the powder mixture it was conformed cylindrical samples by uniaxial pressing using
300 MPa. Pressed samples were sintered during 2 h in an electrical furnace at 1500°C. During sintered it was
used an argon atmosphere inside the furnace in order to inhibit metal oxidation. XRD results indicate that
alumina and metals retain its crystalline structure. Reached density by samples is small and less than 90%.
Scanning electron microscopy observations show alumina’s microstructure with very fine and homogeneous
distributions of metal particles. Both the Mn and Si are not suitable metals to improve the mechanical properties
of alumina, in particular the fracture toughness. Considered rare earth metals such as yttrium and lanthanum,
have yielded favorable results in improving the fracture toughness of the alumina. However, it should be made
more dense materials with them to better explore this potential.
Keywords – Fracture toughness, Ductile particles, Reinforcement, Alumina, Composites
I. INTRODUCTION
Alumina (Al2O3) ceramic presents good mechanical properties such as: high hardness, high compressive
strength, good chemical and thermal stability. However, its applications as structural material have been limited
principally by its low fracture toughness. Al2O3 ceramics can be toughened with the incorporation of fine
metallic particles [1-6], for this reason it has been prepared successfully some Al2O3-systems by different
techniques such as: pressure-assisted thermal explosion [6], slip casting [7], metal infiltration [8-10], sintering
high pressing [11], Chemical deposition [12], self-propagation high temperature synthesis [13] and reaction
synthesized [14]. Nevertheless, most of these processes are costly and they are very complex in their procedures
and control. From these studies authors have been documented that fracture toughness of a ceramic-metal
composite can be controlled by the volume fraction of metallic phase as well as the size of metal particles and
its homogeneous distribution in the ceramic matrix. With these considerations in mind, a simple and cheaper
process was developed for the production of ceramic-metal composites [15]. High-energy ball milling combined
with pressureless sintering can be a substitute low-cost method for the production of ceramic-metal composite.
The aim of this study is to synthesize Al2O3-based composites reinforced with 10 wt. % of La, Mn, Si or Y
using powder techniques in order to determine the effect of each metal on the fracture toughness of the alumina-
matrix. The contents of each section may be provided to understand easily about the paper.
II. EXPERIMENTAL
Starting materials were: Al2O3 powder (99.9 %, 1m, Sigma-Aldrich, USA) and the following powder
metals (La, Mn, Si and Y all of them with 99.9% purity, and sizes between 1-2m, Sigma-Aldrich, USA). The
used amount of powders is that one that allows at the end of the processing let to obtain the composite Al2O3-10
vol.% of the corresponding metal. The powders were milled and mixed in dry in a horizontal mill, using a
rotation speed of 300 rpm, during 12 h, with the help of ceramic jars and using YSZ's balls as grinding elements,
the relation; weight of powder/weight of balls was 1:25. With the powders mixture, they were made cylindrical
samples by uniaxial pressing using 200 MPa with the following dimensions: 20 mm in diameter x 3 mm in
thickness. Afterward, the pressed samples were pressureless sintered at 1500°C during two hours in an electrical
furnace with gas argon atmosphere. The speeds of warming and of cooling were kept constant and equal to
10°C/min. The characterization of the synthesized products was of the following way: Densities were evaluated
by Arquimedes' method. Crystalline phases present en each fabricated composite was analyzed by X-ray
diffraction. The microstructure of the composites was observed with a scanning electron microscopy (SEM),
this SEM was equipped with an energy dispersive spectroscopy detector (EDS), on the way to realize chemical
analyses in the samples’ microstructure. The elastic modulus was determined by the ultrasonic method.
2. Alumina-Based Composites Reinforced with Ductile Particles
www.ijres.org 61 | Page
Microhardness measurements were evaluated with the help of a Vickers indented; finally, fracture toughness
was determined by the fracture indentation method, using Evan´s equation [16].
III. RESULTS
3.1 Relative density
The calculation results of the relative density achieved by each sample after sintering is shown in Fig. 1. To
construct this figure it was first determined the theoretical density of each compound using the rule of mixtures,
subsequently sintered density of each sample was evaluated by the method of Archimedes. With these two
values, it could be calculated the density percentage attained for each sample after its sintering. Figure 1 shows
that the density of the control sample was approximately 90 %, while densities reached by the samples with La,
Mn, Si or Y additions, reached only values of 86, 84, 70 and 89 % respectively. Density values that are not very
high, indicating that the diffusion process during the sintering step does not occurred satisfactorily. This could
be due to sintering occurs in the presence of a liquid phase, formed by the fusion of the used metal in each case,
and surely the liquid formed not wet the surface of the alumina, situation that difficult sintering of the
composite.
figure 1. relative density of different fabricated composites.
3.2 X-ray Diffraction
X-ray diffraction patterns of the four sintered composites are shown in Fig. 2. As seen in the corresponding
pattern to each system, the diffraction spectrum shows just the presence of the alumina and the metal-added. The
presence of any oxide, or other element or compound outside the initial composition of the composite is not
observed, indicating that there was no contamination in any step of the process.
figure 2. x-ray diffraction patterns of the sintered composites.
3. Alumina-Based Composites Reinforced with Ductile Particles
www.ijres.org 62 | Page
3.3 Microstructure obsrved with optical microscope
Microstructure photographs taken with an optical microscope of each manufactured composite are shown in
Fig. 3. Overall are observed fine microstructures with good dispersion of a clear and bright phase, which should
be the added metal to each composite. While density measurements indicate the presence of more than 10%
porosity in all samples, porosity is not evident in these micrographs. In the case of the sample with silicon, it is
observed higher metal agglomeration in some parts of the matrix, which is due to the lower density of silicon
(2.3 g/cm3
) in comparison to the density of the alumina (4 g/cm3
).
figure 3. optical microstructure of different manufactured composite.
3.4 Microstructure obsrved with scanning electron microscope
The microstructure of the sintered composite observed using a scanning electron microscope (SEM) is
shown in Fig. 4. In the same figure 4, it is presented the resulting EDS spectrum realized in the bright particles
of the microstructure of each sample. According to EDS patterns the metallic phase are the smaller and bright
particles located mainly in intergranular positions. While the darkest phase corresponds to that of the alumina
ceramic matrix. In all cases the grain size of the matrix is very similar and close to a micron, microstructure
presents some homogeneity, although in these pictures the presence of porosity is clear and corresponds to the
measures realized by the Archimedes’ method. Although, the melting point of the metals used is below the
sintering temperature, indicating that it should have a liquid phase formed during sintering, it is not observed
traces of it in the microstructure.
Figure 4. SEM microstructure of different manufactured composite.
4. Alumina-Based Composites Reinforced with Ductile Particles
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3.5 Mechanical Properties
3.5.1 Young’s Modulus
The measurement results of Young's modulus for each composite are presented in Fig. 5. This figure shows
that in all cases the value of Young's modulus observed for the control sample (monolithic alumina) is well
above of the modules achieved by other samples. This is due to the higher density attained by the monolithic
alumina. The sample with silicon has reached a very low densification; consistently it has a very small value of
the elastic modulus.
figure 5. young's modulus of sintered composites.
3.5.2 Microhardness
The results of the measurement of microhardness of each sintered sample are shown in Fig. 6. Again in this
figure it is apparent that hardness of the pure alumina is well above than hardness of different composites. This
result is logical and has two explanations, The first one is due to the greater degree of densification achieved by
purely ceramic sample, the second is that when it is added a ductile metal, much less hard than the ceramic
matrix, clearly, the final hardness of the resultant composite will be less. On the other hand, yttrium sample is
the best densified, therefore it has a high value of microhardness.
figure 6. microhardness of each sintered sample.
3.5.6 Fracture Toughness
Values of fracture toughness for each sintered composite are shown in Fig. 7. From this figure when it is
considered the standard deviations for each case, is that the values of fracture toughness of the monolithic
alumina and reinforced composites with silicon or manganese are very similar, so that it can be commented that
nor silicon or manganese are good to improve the fracture toughness of the alumina. On the other hand, values
of this property when lanthanum or yttrium is used as reinforcing there is an improvement of 13% and 16%
respectively, although these values are not very significant, them support the hypothesis that this type of metals
may be promising in the reinforcement of alumina. If it could be adjusted processing conditions to achieve
higher densification in the fabricated composites when these metals are used, probably also the fracture
toughness could increases significantly. Different authors have reported that the mechanism of enhancement of
the alumina, by metals, is due to the closure of cracks through the metal tap when they tend to grow [17].
5. Alumina-Based Composites Reinforced with Ductile Particles
www.ijres.org 64 | Page
Figure 7. Fracture toughness of each fabricated composite.
IV. Conclusions
o Through the proposed methodology it could be fabricated alumina-based materials with additions of La,
Mn, Si and Y with almost 90% of densification.
o Both the Mn and Si are not suitable metals to improve the mechanical properties of alumina, particularly
fracture toughness.
o Rare earth metals such as yttrium and lanthanum have yielded favorable results in improving the fracture
toughness of the alumina. However, it should be fabricated denser materials with them to better explore this
potential.
V. Acknowledgements
The microscopy laboratory facility given by IMP and processing laboratories of UAM-A, UAEM and UPV
is appreciated. In addition, authors are grateful to UAM-A by the support given to carry out this work
through Project 2231212.
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