This document describes research into using additive manufacturing and investment casting to create sub-millimeter metal lattice structures. Stereolithography is used to create sacrificial scaffolds that are embedded in an investment matrix. The scaffolds are sublimated, leaving pores that are filled with ZAMAK alloy during casting. Two casting methods, spin casting and gravity casting with vacuum assist, are compared. Compression testing shows the two methods produce lattices with comparable mechanical strengths, demonstrating the viability of using these techniques to create sub-millimeter metal lattices.
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.
Influence of volume fraction, size, cracking, clustering of particulates and ...eSAT Journals
Abstract
The objective of this study is to examine the influence of volume fraction, size of particulates, formation of precipitates at the
matrix/particle interface, particle cracking, voids/porosity, and clustering of particulates on the strength and stiffness of
6063/SiCp metal matrix composites. Tensile strength and stiffness increase with an increase in the volume fraction of SiC
particulates. The tensile strength and stiffness decrease with increase in size of the particulates, presence of porosity, clustering,
and particle cracking. Formation of particulate clusters is more prominent in the composites having very small-reinforced
particulates. Mg2Si compound is likely to precipitate at the matrix/particle interfaces of 6063/SiC composite.
Keywords: 6063, SiC, clustering, cracking, porosity, clustering
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
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.
Performance of Self Compacting High Strength Fiber Reinforced Concrete (SCHSFRC)IOSR Journals
In this experimental study the changes on some mechanical properties of self compacting concrete
specimen produced by silica fume, metakaolin, fly ash and steel fibers were investigated. The main objective of
this is to obtain ductile Self Compacting High Strength Concrete (SCHSC) which flows under its own weight
and homogeneity while completely filling any formwork and passing around congested reinforcement. The Self
Compacting High Strength Concrete produced by using silica fume, metakaolin, fly ash, steel fibers and
Polycarboxylatether base superplasticizer. Three types of steel fibers were used in the experiments and volume
fractions of steel fiber were 0.5% to 4.0 %. Addition of silica fume, metakaolin and fly ash into the concrete
were 2.5 %, 2.5 % and 10 % by weight of cement content respectively. Water/cement ratio was 0.29.
Compressive strength and split tensile strength tests were made on hardened concrete specimens.
Characteristics of Hypoeutectic Cu-Zr Alloy Rods Manufactured by Vertical Upw...Rautomead Limited
The focus in this study is therefore on applying a vertical upwards continuous casting (VUCC) mass-production
method to the pilot-scale manufacturing of Cu-Zr alloy rods. The microstructure and physical characteristics of these
VUCC rods were subsequently investigated and compared with rods produced by CMC. In addition, the wire-drawing
capability of the VUCC rods was examined, and the adaptability of the VUCC method to the mass production of
hypoeutectic Cu-Zr alloys was fully investigated.
2.
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.
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.
Influence of volume fraction, size, cracking, clustering of particulates and ...eSAT Journals
Abstract
The objective of this study is to examine the influence of volume fraction, size of particulates, formation of precipitates at the
matrix/particle interface, particle cracking, voids/porosity, and clustering of particulates on the strength and stiffness of
6063/SiCp metal matrix composites. Tensile strength and stiffness increase with an increase in the volume fraction of SiC
particulates. The tensile strength and stiffness decrease with increase in size of the particulates, presence of porosity, clustering,
and particle cracking. Formation of particulate clusters is more prominent in the composites having very small-reinforced
particulates. Mg2Si compound is likely to precipitate at the matrix/particle interfaces of 6063/SiC composite.
Keywords: 6063, SiC, clustering, cracking, porosity, clustering
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
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.
Performance of Self Compacting High Strength Fiber Reinforced Concrete (SCHSFRC)IOSR Journals
In this experimental study the changes on some mechanical properties of self compacting concrete
specimen produced by silica fume, metakaolin, fly ash and steel fibers were investigated. The main objective of
this is to obtain ductile Self Compacting High Strength Concrete (SCHSC) which flows under its own weight
and homogeneity while completely filling any formwork and passing around congested reinforcement. The Self
Compacting High Strength Concrete produced by using silica fume, metakaolin, fly ash, steel fibers and
Polycarboxylatether base superplasticizer. Three types of steel fibers were used in the experiments and volume
fractions of steel fiber were 0.5% to 4.0 %. Addition of silica fume, metakaolin and fly ash into the concrete
were 2.5 %, 2.5 % and 10 % by weight of cement content respectively. Water/cement ratio was 0.29.
Compressive strength and split tensile strength tests were made on hardened concrete specimens.
Characteristics of Hypoeutectic Cu-Zr Alloy Rods Manufactured by Vertical Upw...Rautomead Limited
The focus in this study is therefore on applying a vertical upwards continuous casting (VUCC) mass-production
method to the pilot-scale manufacturing of Cu-Zr alloy rods. The microstructure and physical characteristics of these
VUCC rods were subsequently investigated and compared with rods produced by CMC. In addition, the wire-drawing
capability of the VUCC rods was examined, and the adaptability of the VUCC method to the mass production of
hypoeutectic Cu-Zr alloys was fully investigated.
2.
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.
The present research work is on bronze alloy metal matrix composite reinforced with fly ash particulate in
weight percentage of 3%, 6% and 9%. The specimens can be produced by Liquid metallurgy technique (Stir casting
method) will be used to produce metal matrix composites using Aluminum Copper alloys as matrix material. The
produced composites will be characterized with respect to mechanical properties and wear properties. Results
obtained from the above investigation, it can be seen that the rate of wear is decreased with increasing bronze and
will be helpful for the end of users in the foundry of automobile and aerospace industries.
Analysis and quantification of grain size in various dhp copper tubes manufac...Rautomead Limited
Abstract. Deoxidized High Phosphorus (DHP) Copper tubes are frequently used in numerous
industrial and household applications. To ensure the acceptability of DHP copper tubes prepared by
various industrial processes, the quality of the DHP copper tubes must be evaluated and one of the
best ways to do so is to examine the microstructure and metallography and quantify grain size. In
this paper the authors considered the average grain size of copper tube samples made traditionally
as well as by the planetary rolling and CastTube process. Because of the small thickness of the
CastTube samples, in certain circumstances traditional methods of grain counting were not
plausible and a new procedure for grain counting needed developed. This paper is about the
development and evaluation of grain sizes in continuously cast tube samples using both the
planimetric procedure (ASTM E112) and a new method, which will be herby, referred to as the
“total grain counting method”. This paper also concludes that there is a large difference in the grain
size of tubes with different manufacturing methods.
Performance of Composite Materials Using a Novel Techniqueinventionjournals
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.
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
A review on advanced ceramic processing techniquesAlokjyoti Dash
This Presentation enlists and describes most ceramic process and most parameters which affect these ceramic processing. A reader shall understand the basic of these presented process to fabricate unique ceramic materials
The Recycling of Steel and Brass Chips to Produce Composite Materials via Col...theijes
In this study a novel method of direct conversion of brass (CuZn30) and steel (S355JR) chips into finished product without melting is introduced as an alternative to melting process. CuZn30 Brass and S355JR steel chips were used as constituents of composite materials. The chips were cold pressed at room temperature and were subjected to liquid phase sinterization. Hardness, compression and three point bending tests were used to investigate the mechanical properties of the obtained composite materials and compared with cast CuZn30 brass. The produced composite materials are shown to have comparable mechanical properties with bulk brass. It is also shown that the proposed method can be considered as an alternative to conventional production methods such as melting, extrusion ect. with relatively low costs.
Wear and Corrosion Study of Sputtered Zirconium thin films on SS316L for Wind...IJERA Editor
The Aim of this study is to observe the Wear and Corrosion behavior of Zirconium coated 316L stainless steel. After polishing, SS316L was coated with Zirconium employing DC sputtering process (a technique of physical vapor deposition).Structure characterization techniques including Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) were utilized to investigate the microstructure and crystallinity of the coating. Salt spray test was performed by spraying Sodium chloride in order to determine corrosion resistance behavior of the coated sample. Pin on disc wear test was performed by hardened and tempered EN31 steel pin in order to determine and compare the Wear resistance behavior of Coated and uncoated samples. The Objective is to recommend the zirconium coated Stainless steel SS316L can be a choice for Off-shore wind mills where the shafts undergo Wear and corrosion problems.
EFFECT OF ANTIMONY ADDITION RELATIVE TO MICROSTRUCTURE AND MECHANICAL PROPERT...Rautomead Limited
It is well documented that the addition of antimony in pure lead increases tensile strength and reduced elongation. The goal of the present work is to identify the cause of these phenomena by investigation of the effects of the addition of Sb (1.25%) on the structure of pure continuously cast lead and lead alloy rods. The microstructure and morphology of both pure lead and lead 1.25% antimony were examined by digital optical microscope and scanning electron microscope respectively. Energy Dispersive X-ray Spectroscopy (EDX) was used to identify alloying elements. The results showed that the effect of additions of antimony on mechanical properties of lead-antimony alloys is mainly due to the solid solubility of the antimony element. Homogenized distribution of the antimony results in a decrease in the grain size of the pure lead. These smaller grains mean higher strength so long as there is a homogeneous grain structure
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 International Journal of Engineering and Science (The IJES)theijes
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.
Squeeze cast process on aluminium matrix composites(AMC
), basic process theory, process parameters, desirable property change, strength, optimum process parameters..
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.
The present research work is on bronze alloy metal matrix composite reinforced with fly ash particulate in
weight percentage of 3%, 6% and 9%. The specimens can be produced by Liquid metallurgy technique (Stir casting
method) will be used to produce metal matrix composites using Aluminum Copper alloys as matrix material. The
produced composites will be characterized with respect to mechanical properties and wear properties. Results
obtained from the above investigation, it can be seen that the rate of wear is decreased with increasing bronze and
will be helpful for the end of users in the foundry of automobile and aerospace industries.
Analysis and quantification of grain size in various dhp copper tubes manufac...Rautomead Limited
Abstract. Deoxidized High Phosphorus (DHP) Copper tubes are frequently used in numerous
industrial and household applications. To ensure the acceptability of DHP copper tubes prepared by
various industrial processes, the quality of the DHP copper tubes must be evaluated and one of the
best ways to do so is to examine the microstructure and metallography and quantify grain size. In
this paper the authors considered the average grain size of copper tube samples made traditionally
as well as by the planetary rolling and CastTube process. Because of the small thickness of the
CastTube samples, in certain circumstances traditional methods of grain counting were not
plausible and a new procedure for grain counting needed developed. This paper is about the
development and evaluation of grain sizes in continuously cast tube samples using both the
planimetric procedure (ASTM E112) and a new method, which will be herby, referred to as the
“total grain counting method”. This paper also concludes that there is a large difference in the grain
size of tubes with different manufacturing methods.
Performance of Composite Materials Using a Novel Techniqueinventionjournals
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.
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
A review on advanced ceramic processing techniquesAlokjyoti Dash
This Presentation enlists and describes most ceramic process and most parameters which affect these ceramic processing. A reader shall understand the basic of these presented process to fabricate unique ceramic materials
The Recycling of Steel and Brass Chips to Produce Composite Materials via Col...theijes
In this study a novel method of direct conversion of brass (CuZn30) and steel (S355JR) chips into finished product without melting is introduced as an alternative to melting process. CuZn30 Brass and S355JR steel chips were used as constituents of composite materials. The chips were cold pressed at room temperature and were subjected to liquid phase sinterization. Hardness, compression and three point bending tests were used to investigate the mechanical properties of the obtained composite materials and compared with cast CuZn30 brass. The produced composite materials are shown to have comparable mechanical properties with bulk brass. It is also shown that the proposed method can be considered as an alternative to conventional production methods such as melting, extrusion ect. with relatively low costs.
Wear and Corrosion Study of Sputtered Zirconium thin films on SS316L for Wind...IJERA Editor
The Aim of this study is to observe the Wear and Corrosion behavior of Zirconium coated 316L stainless steel. After polishing, SS316L was coated with Zirconium employing DC sputtering process (a technique of physical vapor deposition).Structure characterization techniques including Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) were utilized to investigate the microstructure and crystallinity of the coating. Salt spray test was performed by spraying Sodium chloride in order to determine corrosion resistance behavior of the coated sample. Pin on disc wear test was performed by hardened and tempered EN31 steel pin in order to determine and compare the Wear resistance behavior of Coated and uncoated samples. The Objective is to recommend the zirconium coated Stainless steel SS316L can be a choice for Off-shore wind mills where the shafts undergo Wear and corrosion problems.
EFFECT OF ANTIMONY ADDITION RELATIVE TO MICROSTRUCTURE AND MECHANICAL PROPERT...Rautomead Limited
It is well documented that the addition of antimony in pure lead increases tensile strength and reduced elongation. The goal of the present work is to identify the cause of these phenomena by investigation of the effects of the addition of Sb (1.25%) on the structure of pure continuously cast lead and lead alloy rods. The microstructure and morphology of both pure lead and lead 1.25% antimony were examined by digital optical microscope and scanning electron microscope respectively. Energy Dispersive X-ray Spectroscopy (EDX) was used to identify alloying elements. The results showed that the effect of additions of antimony on mechanical properties of lead-antimony alloys is mainly due to the solid solubility of the antimony element. Homogenized distribution of the antimony results in a decrease in the grain size of the pure lead. These smaller grains mean higher strength so long as there is a homogeneous grain structure
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 International Journal of Engineering and Science (The IJES)theijes
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.
Squeeze cast process on aluminium matrix composites(AMC
), basic process theory, process parameters, desirable property change, strength, optimum process parameters..
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.
Dynamic Analysis of Double-Skin Composite Steel PlatesIOSR Journals
Double Skin Composite (DSC) plates are subjected to impact required to cause complete perforation and the accompanied failure modes are investigated. The amount of energy absorbed is calculated by capturing the residual velocity of penetrator after perforating the lower plate. The difference in initial kinetic energy and residual kinetic energy is the amount of energy absorbed by the panel. In the present paper a non-linear three-dimensional finite element models for Double Skin Composite panels subjected to dynamic loading is introduced. Pilot model is used to investigate the failure pattern in the composite panel when subjected to impact loads by rigid steel penetrator, while the other models are used to analyze the energy absorption capacity of such system when perforated. Results showed that such elements have good ability of absorbing energy when subjected to perforation, due to ductility of lower plate skin and vertical stiffness of lower shear studs.
. One of the methods used to surface hardening of ductile iron is chilled cast iron. Chill as the fast cooling rate in the mold during solidification and chill thickness greatly affects the thickness of the hardness layer. The main material used is ductile iron, and the chill material is SS 304. Casting uses the sand casting method. Before pouring, the chill plate has been inserted onto the surface of the pattern that has been formed in the mold, then the chill plate is preheated at 700OC. Pouring was carried out at a melting temperature of 1400OC, and then cooled with argon and O2 sprays into the mold in solidification conditions at exactly 700OC. The results analyzed were the microstructure, hardness value, and the hardness of the thickness layer. This chill coolant will absorb heat very quickly and the Cr and Ni alloy will diffuse to the specimen surface to stabilize the ferrite and austenite phases in the final solidification. The particles on the hard surface have Ferro carbide M7C3, which is in the form of cementite and martensitic phases so that to categorized as white cast iron structure formed on the surface with an area around 1.5-3mm has a hardness of 61-65HRC. But in the center area is 31-49HRC
Twin Roll Casting of Aluminum Alloy AC7A Using Commercial Scale MachineIJAEMSJORNAL
Twin roll casting process is able to produce a strip from molten metal directly. Thus this process has a possibility to reduce total cost of sheet making comparing to conventional rolling process. Strip casting process has some disadvantages. Casting speed depends on the material properties. It is difficult to determine the casting conditions. Twin roll casting of aluminum alloy AC7A using commercial scale machine was operated. The aims of this study is to investigate the effect of the roll speed. Continuous strip could not be produced at the roll speed 5 m/min. Continuous strip could be produced at the roll speed 10 m/min. However, cracks were observed. Continuous strip could be produced at the roll speed 20 m/min. However, cracks were observed too.
Modeling and finite element analysis for a casting defect in thin wall struct...Dr.Vikas Deulgaonkar
The casting of pump impeller blades is a difficult operation due to its thin wall structure. In the casting process for thin wall impeller structure, the prediction of shrinkage defect is a one of the important issue and failure of such thin wall structure is a commonly encountered problem. The non-uniform heat transfer rate is the main cause of such failure. The uniformity of heat transfer rate may enhance by placing the runner at appropriate position and riser based on the geometrical attributes. The flow of liquid metal and its solidification has time based temperature variation, shrinkages and porosity distributions in such structures. An attempt is made for the analysis of optimization in the placement of runner and riser through this experimentation. The experiment contains the analysis of finite element simulation of fluid flow and solidification of metal execution at various temperatures, prediction of shrinkages based on the geometry of the casting and flow curvature and porosity distribution. This work also focuses on the prediction of casting defects in aluminum thin wall pump impeller structure using commercially available software (ANSYS-FLUENT). The experimental validation of the simulation result is also done to confirm the same.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
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.
An investigation of Effect of Mould Vibrations on Mechanical and Metallurgica...journal ijrtem
Abstract: Casting is one of the oldest and mostly used production processes in industry. The traditional casting has certain disadvantages like poor strength due to hot tears, shrinkage and poor surface finish. The property of casting process mostly depends on the microstructure after solidification. Providing Mould vibration during casting is one of the latest techniques employed in order to get better structure in the solidified casting. Mould vibration during casting gives reduced amount of shrinkage, better morphology, surface finish, and less chances of hot tear. In this research work, the effect of mould vibration during solidification of Aluminum 356alloys for different values of wavelengths at a fixed pouring temperature investigated to understand the modification in microstructure and mechanical properties of casting. The Al356 casting has been prepared in a graphite mould with and without vibrations. The frequencies are varied from 0 Hz to 20 Hz during the casting process. A casting has been made without vibration as well to compare the results of castings with vibration. The experimental results showed significant grain refinement and remarkably improvement in compression strength and hardness of castings with mechanical mould vibration during solidification. Key words: Mould Vibrations, Stir casting, Vibrating table, Ultimate tensile strength, hardness and microstructure.
Investigation on Flexural Behaviour of Cold Formed Latticed Built-Up BeamDr. Amarjeet Singh
There are two structural members used in steel construction the hot rolled members and the cold formed members. They are light members compared to the traditional heavier hot rolled steel structural members used in the field. They have high strength to weight ratio resulting in less dead weight making it a good option in construction of bridges roof trusses transmission line towers multi storied buildings and other structural members. This paper is done to understand the flexural capacity and to enhance it by developing innovative latticed cold formed steel beam. The impact of web opening of the cold formed beam on the flexural behavior of cold formed built-up I section under two point loading is investigated for the simply supported end conditions. Numerical analysis is performed using finite element analysis (FEM) software. From results, the load vs. Deflection curve, failure modes and ultimate load carrying capacity of the specimen presented in this paper. Therefore the main focus of this project is to investigate the flexural behavior of these steel members and by replacing the lattice hot rolled section by cold formed steel sections. The ultimate load carrying capacity with failure mode of simulated FEA models was compared with experimental results.
1. 1
11th
International Conference on Micro Manufacturing
Orange County, California, USA, March 2016
Paper#65
Use of additive manufacturing in creating sub-millimeter
micro-architectured structures via investment casting
Neng Li1,2,*
, Yi-chen Lin1,*
, Benjamin Dolan3
, Lawrence Kulinsky1
1
Mechanical and Aerospace Engineering Department, University of California, Irvine
2
Beijing Institute of Aeronautical Materials, Beijing, China
3
RapidTech, University of California, Irvine
*
Both authors contributed equally to this manuscript
Abstract
Present work describes extension of the investment casting to production of metal lattices with sub-millimeter
diameter trusses. The stereolithography is used to create a sacrificial scaffold that is embedded in the investment
matrix with subsequent sublimation to create a system of 750-micron diameter pores that are filled with ZAMAK
alloy during casting. The metal lattices are created with two alternative approaches – spin casting and gravity
casting (with vacuum assist). Compression testing of lattice structures demonstrates that two casting technologies
produce metal lattices with comparable mechanical strengths.
Keywords: Metal lattice structures, additive manufacturing, stereolithography, investment casting,
micromanufacturing.
1. Introduction
There is a significant interest in maximizing
strength of materials while minimizing the weight of
the corresponding structures for a variety of
applications from civil engineering to aero-space and
automotive industries [1,2]. In order to manufacture
structures with superior strength-to-weight ratios,
recent developments emphasize the use of
micro-architectural materials (also called
meta-materials) where rather than using a solid block
of material a lattice or foam structure is created [3,
4]. Historically lattice truss structures are found at
large length scales (such as bridges and buildings).
The improvements in strength-to-weight ratios are
based on the principle that the trusses within the
structures predominately experience axial stresses
(tension or compression) when loaded, thus capable
to withstand higher loads than in the bending modes
[5]. After scaling these structures to millimeter
lengths and smaller, substantial improvements in
strength and stiffness have been predicted [6].
It has been challenging so far to manufacture
sub-millimeter metal lattice. Recent attempts in this
area are connected to the emergence of additive
manufacturing (AM). AM methods are capable of
producing lattice structures with controllable pore
shapes and sizes where truss diameter can be in
sub-millimeter region, but most of the demonstrated
approaches involve significant time and expense to
produce these structures. For example, some
sub-millimeter lattices have been produced with
Direct Metal Laser Sintering (DMLS) – quite
expensive process even for small parts [7]. Another
approach was to use stereolithography (SLA) for
manufacturing resin-based sacrificial lattice
structure, using seedless electroplating on the surface
of these lattices with subsequent high temperature
exposure that causes sacrificial lattice to vaporize
leaving hollow metal lattice structure [8]. The latter
technique is also expensive and time consuming.
2. 2
Present work demonstrates our approach to
development of an inexpensive process for
producing sub-millimeter metal lattices. The study
focuses on fabrication sequence that involves
stereolithography to produce the sacrificial lattice
structure, encasing the lattice within the investment
matrix, sublimating the sacrificial lattice, and then
using either gravity casting or spin casting of
ZAMAK3 alloy to produce the finished metal lattice.
The lattices produced via gravity casting and spin
casting were subjected to compression tests using the
Instron 3367 test frame. Visual observations and
final element modelling are also performed.
2. Experimental Procedure
2.1 Fabrication
The process flow is shown in Figure 1. The
cellular lattice structure investigated in this paper is
shown in Fig. 2. The diameter of struts is 750 µm.
The Body Centered Cubic (BCC) structure was
selected for the lattice unit cell. The cell topology is
given in Fig. 2 (b). The lattice consists of 2 layers of
9 units each as seen in Figure 2(a). The overall
dimensions of a sample are 20mm long, 20mm wide,
16mm tall, while the thickness of the top and bottom
platforms are 2 mm.
A three-dimensional (3D) CAD model is
generated with the Solidworks software (Dassault
Systemes SolidWorks Corp.). The STL file is
exported and sliced into a series of 2D layers in a
custom software of digital stereolithography (SLA)
system B9Creator1.2 (B9Creation, Corp., USA).
B9cherry resin is exposed in layer-by-layer sequence
as platform is raised 50 microns per step. The lattices
manufactured via SLA is shown in Figure 3.
The Plasticast (Ransam & Randolph Corp.,
USA) Investment is mixed with water in 100:38
volume ratio. In order to avoid premature
solidification, the mixing should be done within 3
minutes. The investment mix is then placed in a
vacuum chamber for 2 minutes for degassing. Pour
the degassed investment mix down the side of the
investment flask (Ransam & Randolph Corp, USA,
diameter 44.5mm, height 44.5mm for spin casting;
diameter 76.2mm, height 101.6mm for gravity
casting) where the lattice with the attached wax
filaments is placed. Vacuum the invested flask about
1.5 min and fill the flask to the top edge of the
investment flask. It is critical not to agitate the flask
during the process of solidification at room
temperature for 2 hours. After hardening, remove the
sprue base and start to burn out the wax pattern. The
wax burnout schedule is given in Table 1.
The lattices produced via stereolitography are
used as sacrificial structures to generate a negative
pattern of the channels filled with a metal during
investment casting process. Present study compares
lattices produced with two different investment
casting techniques: a gravity casting and a spin
casting. In this paper, the alloy selected for casting
was ZAMAK3 zinc alloy widely used due to its low
melting point (385℃) and good fluidity in a molten
state.
2.1.1. Gravity casting
In order to increase the hydrostatic head of the
poured metal, the cylindrical funnel is used (see
Figure 4(a)). The mold is heated according to the
schedule in Table 1 and cooled to 480℃before
Figure 2. Lattice design: (a) Lattice;
(b) Structure of the unit cell
(a) (b)
Figure 3. Lattices manufactured via SLA
Figure 1. Process flow
3. 3
casting. While significantly above the melting
temperature of the alloy used, experimentation
indicated that mold temperature of 480℃ resulted in
the highest success rate. The mold is then set on a
vacuum investment table. A vacuum of -100 KPa is
then applied to the bottom of the mold to assist in
drawing the material into the mold and reducing the
likelihood of voids. The metal
is poured into the funnel and the negative pressure is
applied for 1 min after which the pressure is released
and the metal is allowed to solidify for 15 minutes at
the room temperature. Subsequently the mold is put
into cold water to clear out the investment and
separate the resulting metal lattice.
2.1.2. Spin casting
The spin casting is prepared by rotating the arm
at least 3 full rotations and locking the arm in place
with a pin. Once again, the mold heated to 480℃ is
then removed from the furnace and placed in the
carrier at the end of the spin arm. The crucible
(movable ceramic container into which the metal is
poured) is moved to touch the mold. Metal is poured
into the crucible and heated with a blow torch to stay
liquid. The pin is released and the centrifugal force
caused by the rotation of the spin arm pushes the
liquid metal into the mold and fills its cavities.
Because of the smaller size of the mold and due to
convective cooling during the spinning the
solidification of the metal happens much faster
during the spin casting than for gravity casting.
Within 5 minutes after the casting the mold can
be placed in the cold water and the metal lattice can
be separated from the investment. The process of
spin casting is shown in Figure 4(b). Metal lattice
structures formed with the gravity casting and spin
casting can be seen in Figure 5.
Figure 5. Investment casting results for:
(a) Gravity casting; (b) Spin casting
2.2 Mechanical characterization
To prepare the samples for mechanical testing,
the metal tubes and fibers that were conduits for the
molten metal into and out of the lattice structures are
sawed off and the top and bottom surfaces of the
lattice structures are planarized and polished with an
end mill on the milling machine (model 2831237,
Bridgeport Corp., USA). The compression tests were
carried out at room temperature using INSTRON
3367 testing machine (INSTRON Corp., USA) at
room temperature. Loads and displacements were
recorded. The loading rate was set up to 5mm/min.
3. Results and Discussion
3.1 Finite Element Modeling
We have used finite element modeling to
estimate the elastic modulus of the lattices and yield
strength of cellular lattices. The models aim to
Flask size: up to 6.3 cm (diameter) × 6.3
cm(height)Using for spin casting
Flask size: up to 10.2 cm (diameter) × 15.2
cm (height) Using for gravity casting
Step 1:Dry out Ambient to 150℃ and hold 1 hour Ambient to 150℃ and hold 3 hours
Step 2:Dewax Raise over 1 hours to 370℃ and hold
1 hours
Raise over 1.5 hours to 370℃ and hold
1.5 hours
Step 3:Wax
burnout
Raise over 2 hours to 730℃ and hold
2 hours
Raise over 2 hours to 730℃ and hold
2 hours
Step 4:Prepare for
casting
Reduce to casting temperature allow for stabilization.
(a) (b)
Table 1. Investment Mold Heating Schedule
(a) (b
)
Spring
Crucible
Flask
Figure 4. Investment casting:
(a) Gravity casting; (b) Spin casting
4. 4
describe the behaviour of the structures under
compressive loads. All the simulations are performed
by the commercial finite element software
Solidworks (Dassault Systemes SolidWorks Corp.).
The mesh of the lattice includes 119536 nodes and
73784 elements.
3.2 Boundary Conditions
To coincide with the experimental uniaxial
compression test, the translational degrees of
freedom on the bottom face of the lattice are fixed
while the rotational ones are free. For the upper face
of the lattice, all the translational degrees of freedom
are fixed except in the loading direction. The contact
between the specimens and loading instruments in
the normal direction is set as a hard contact, which
preserves the planarity of the top and bottom planes
of the lattice. The displacement of the top platform is
set as a control factor. The force and displacement
are predicted by the simulation and a stress strain
curve can be plotted.
3.3 Deformation of the lattice
Figure 6. Simulated lattice structure under
compression indicating distributions of: (top) Von
Mises Stress;(bottom) Strain
The simulated lattice structure under the strain
of 7.8% is presented in Figure 6. Initially,
compression results in an elastic deformation of the
lattice. The strain contours show that, almost all the
compressive load is carried by the struts nodes. By
increasing the applied force, the struts start to buckle
and a fracture initiates at the nodal regions. The
highest stress is experienced by the nodes at the
corners of the lattice structure. Figure 6 illustrates
the Von Mises stress distribution in the lattice at
7.8% strain. The maximum value of residual stress
could reach to 89 MPa, while the minimum value is
9.2 MPa. The figure shows that the stress distribution
is similar for each unit cell and that highest stress
and thus the plastic deformation (buckling) will
occur in the trusses at the locations closest to the
nodes, while the lowest stress level is in the trusses
between the nodes.
3.4 Mechanical characterization results
Figure 7 shows the manufactured cellular lattice
structure under compression during mechanical
testing. Figure 8 presents the results for mechanical
testing of the representative samples produced via
gravity casting and spin casting as well as simulation
results. It can be seen that the samples produced via
spin casting and via gravitational casting behave
nearly identical under compression. It is also evident
that simulation overestimates the strength of the
structure, likely due to the fact that it does not
account for internal defects of the structures created
Figure 7. Compression test on Instron 3367
Figure 8. Load-Displacement curves for
microfabricated metal lattices
5. 5
during fabrication process.
4. Conclusion
A micromanufacturing process flow to create metal
lattices with 750 micron diameter trusses involves
creation of sacrificial lattice structure via
stereolithography, embedding it in the investment
matrix, performing a heat treatment to create a
designed network of sub-millimeter channels after
submimation of the sacrificial scaffold, and casting
zinc ZAMAK alloy with two alternative methods –
spin casting and gravity casting. Results of
compression tests performed on Instron test station
demonstrated that both, gravity casting and spin
casting produce lattice structures with comparable
strengths.
5. References
[1]. Beyond Engineering: How Society Shapes
Technology (Oxford University Press, Oxford,
1999).
[2]. H.G. Allen, Analysis and Design of Structural
Sandwich Panels (Pergamon Press, Oxford, 1969).
[3]. Deshpande VS, Fleck NA. Collapse of truss core
sandwich beams in 3-point bending. Int J Solids
Struct 2001; 38(36–37):6275–305.
[4]. Deshpande VS, Fleck NA, Ashby MF. Effective
properties of the octet-truss lattice material. J Mech
Phys Solids 2001; 49(8):1747–69.
[5]. J. Borrego, Space Grid Structures: Skeletal
Frameworks and Stressed-Skin Systems (MIT Press,
Cambridge MA, 1968).
[6]. V.S. Deshpande, M.F. Ashby, N.A. Fleck, Foam
topology bending versus stretching dominated
architectures, Acta Materialia, 2001, 49, p.1035
[7]. B. Gorny, T. Niendorf, J. Lackmann, M. Thoene,
T. Troester, H.J. Maier Mater. Sci. Eng. A, 528
(2011), pp. 7962–7967
[8]. T. A. Schaedler, A. J. Jacobsen, A. Torrents, A.
E. Sorensen, J. Lian, J. R. Greer, L. Valdevit, W. B.
Carter, Ultralight Metallic Microlattice, Science, 334
(6058) 962-965 (2011)
Acknowledgements
The authors are grateful to Mr. Steve Weinstock for
his generous support with sample preparation and
mechanical testing.