This document discusses improving the structural integrity of 3D printed 420 stainless steel through the addition of boron-based additives during sintering. It begins by introducing the challenges associated with achieving high density and structural integrity in additive manufacturing parts. It then reviews previous research on using sintering aids like silicon nitride to improve the density of 3D printed stainless steel. The document goes on to explore using lower amounts of boron, boron nitride, and boron carbide as alternative sintering aids to densify 420 stainless steel samples printed via a powder-based 3D printing method. Experimental methods are outlined for mixing the stainless steel powder with different additives and sintering the samples to test how additive type
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.
This document summarizes a study on eliminating white layer formation during hard turning of AISI D3 steel to improve fatigue life. Experiments were conducted using chamfered CBN tool inserts under dry and gas cooling conditions. Results found that gas cooling with argon and CO2 eliminated the white layer, which was over 2 μm thick with dry cutting. Surface hardness was also lower with gas cooling than dry cutting. Microstructural analysis found depletion of iron and chromium and increase in carbon and oxygen in the white layer formed during dry cutting. Gas cooling protected the machined surface and reduced phase transformations. In conclusion, using argon and CO2 gas cooling can eliminate white layer formation during hard turning of hardened steel.
Testing of Already Existing and Developing New Compaction Equations during C...IJMER
Powder Metallurgy (P/M) processing of materials to produce conventional P/M parts
involve the compaction of the pre-determined mass of individual elemental, mixed elemental metal
powders or alloy powders and or composite powders into green compacts and sintering them under
reducing atmosphere and or under other protective coatings, thus, after sintering producing
products after mild machining operations. Therefore, compaction represents one of the most
important stages in the production of engineering components using the P/M route. However, the
physical properties such as density and the stress distribution in the green compacts are determined
not only by the properties of the constituents of the powder or the powder blend, but, also by the
pressing modes and schedules. Thus, the present investigation pertains to generate experimental
data on the compaction behaviour of Fe-1.05% graphitesystems with two different iron particle size
ranges and two different powder masses in order to highlight the various aspects of compaction and
also testing out the already existing compaction equations and search for the new ones. Powder
blends of two different iron powder particle size ranges, namely, -106+53µm and -150+106µm
respectively were blended with the required amount of graphite powder of 3 – 5 µm sizes for a
period of 32 hours. Compaction studies have been carried out for two different amounts of both
powder blends. The two amounts taken were 65g and 85g respectively. However, the main attempt
was made to record the load and the corresponding heights and the top punch displacements for
every two tons (0.02MN) of load which was applied in the steps of 0.02MN. Various equations for
compaction were attempted empirically and the already existing ones were also tested. Critical
analysis of the experimental data and the calculated parameters have resulted into several
compaction equations which were arrived at empirically. The regression coefficient ‘R2
’ in each
case where compactions equations were empirically obtained was in very much close proximity to
unity. However, it has been also confirmed that the data of the present investigation were well
taken up by the earlier compactions equations, thus, validating them comprehensively.
The document discusses the fabrication and characterization of continuous functionally graded materials (FGMs) for a class project. It provides an introduction to FGMs and their applications. The group's objectives are to fabricate a leaf spring using 3D printing with aluminum/glass fiber/epoxy FGM and compare it to conventional leaf springs. The methodology includes a literature review on FGMs and 3D printing techniques, material selection, fabrication using inkjet 3D printing, testing, and results reporting. A Gantt chart outlines the project schedule.
This document discusses the effect of preform geometry on material behavior and densification during hot upset forging of sintered AISI 9840 steel powder metal parts. Powder blends were prepared with different compositions and compacted into preforms with varying initial aspect ratios between 0.45-0.92. The preforms were sintered and hot forged to different height strains. Results showed that lower aspect ratio preforms densified more rapidly than higher ratios. Densification curves followed a third order polynomial relationship with height strain. Preform geometry significantly affected the densification curves and Poisson's ratio with density.
Injection Molding Simulation Analysis of Car Rim Using SolidWorks® PlasticsSheharyar Ghani
1. The document summarizes an analysis of injection molding parameters for a car rim using SolidWorks Plastics simulation software. PEEK polymer with 30% carbon fiber was used as the material.
2. Investigations were conducted on mold filling, packing, cooling, and costing. The number of gates and their location, melt temperature, and mold temperature were varied to study their effects on weld lines, shrinkage, and frozen layer thickness.
3. Increasing the number of gates or melt temperature increased weld lines and shrinkage, while higher mold temperatures decreased the frozen layer thickness. The simulations aimed to determine the most feasible design parameters before further analysis or manufacturing.
The document summarizes an experimental study that evaluated the effect of ferroboron content, welding current, and average welding speed on the microhardness of mild steel plates hardfaced using shielded metal arc welding with a ferroboron paste coating. Taguchi's method was used to design the experiment with three factors (ferroboron content, welding current, average welding speed) each at three levels. Microhardness tests found that microhardness increased with increasing ferroboron content and average welding speed, but decreased with increasing welding current. Analysis of variance identified ferroboron content as having the most significant effect on microhardness. The optimum parameters for maximum microhardness were determined to be 12 mg/mm2 ferro
In manufacturing, many products need to undergo increasing customisation, and a shortening of the manufacturing cycle time. This makes the time needed to produce prototypes one of the most important contributors to product development cycles. Rapid Prototyping (RP) offers the user the ability to optimise part design in order to meet customer requirements with few manufacturing restrictions. One of the most common RP processes is Laser Sintering (LS). A problem with LS is that sometimes the surface of the parts produced displays a texture similar to that of the skin of an orange (the so-called orange peel texture). This problem must be addressed before the technology can gain wider acceptance. The main aim of this research is to develop a methodology of controlling the input material properties that will ensure consistent and good quality of the fabricated parts. From the experiment, it was found that PA12 powder with high melt flow rate, low melting temperature, low glass transition temperature and low degree of crystallization temperature could improve the sintering process to produce a good Laser Sintering (LS) parts with lower shrinkage rate. The powder which has higher melt viscosity and lower melting heat becomes liquid more easily and therefore flows better during the sintering process due to a shorter chain molecular structure. The results of experimental work indicate that the melt viscosity, and part surface finish are correlated.
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.
This document summarizes a study on eliminating white layer formation during hard turning of AISI D3 steel to improve fatigue life. Experiments were conducted using chamfered CBN tool inserts under dry and gas cooling conditions. Results found that gas cooling with argon and CO2 eliminated the white layer, which was over 2 μm thick with dry cutting. Surface hardness was also lower with gas cooling than dry cutting. Microstructural analysis found depletion of iron and chromium and increase in carbon and oxygen in the white layer formed during dry cutting. Gas cooling protected the machined surface and reduced phase transformations. In conclusion, using argon and CO2 gas cooling can eliminate white layer formation during hard turning of hardened steel.
Testing of Already Existing and Developing New Compaction Equations during C...IJMER
Powder Metallurgy (P/M) processing of materials to produce conventional P/M parts
involve the compaction of the pre-determined mass of individual elemental, mixed elemental metal
powders or alloy powders and or composite powders into green compacts and sintering them under
reducing atmosphere and or under other protective coatings, thus, after sintering producing
products after mild machining operations. Therefore, compaction represents one of the most
important stages in the production of engineering components using the P/M route. However, the
physical properties such as density and the stress distribution in the green compacts are determined
not only by the properties of the constituents of the powder or the powder blend, but, also by the
pressing modes and schedules. Thus, the present investigation pertains to generate experimental
data on the compaction behaviour of Fe-1.05% graphitesystems with two different iron particle size
ranges and two different powder masses in order to highlight the various aspects of compaction and
also testing out the already existing compaction equations and search for the new ones. Powder
blends of two different iron powder particle size ranges, namely, -106+53µm and -150+106µm
respectively were blended with the required amount of graphite powder of 3 – 5 µm sizes for a
period of 32 hours. Compaction studies have been carried out for two different amounts of both
powder blends. The two amounts taken were 65g and 85g respectively. However, the main attempt
was made to record the load and the corresponding heights and the top punch displacements for
every two tons (0.02MN) of load which was applied in the steps of 0.02MN. Various equations for
compaction were attempted empirically and the already existing ones were also tested. Critical
analysis of the experimental data and the calculated parameters have resulted into several
compaction equations which were arrived at empirically. The regression coefficient ‘R2
’ in each
case where compactions equations were empirically obtained was in very much close proximity to
unity. However, it has been also confirmed that the data of the present investigation were well
taken up by the earlier compactions equations, thus, validating them comprehensively.
The document discusses the fabrication and characterization of continuous functionally graded materials (FGMs) for a class project. It provides an introduction to FGMs and their applications. The group's objectives are to fabricate a leaf spring using 3D printing with aluminum/glass fiber/epoxy FGM and compare it to conventional leaf springs. The methodology includes a literature review on FGMs and 3D printing techniques, material selection, fabrication using inkjet 3D printing, testing, and results reporting. A Gantt chart outlines the project schedule.
This document discusses the effect of preform geometry on material behavior and densification during hot upset forging of sintered AISI 9840 steel powder metal parts. Powder blends were prepared with different compositions and compacted into preforms with varying initial aspect ratios between 0.45-0.92. The preforms were sintered and hot forged to different height strains. Results showed that lower aspect ratio preforms densified more rapidly than higher ratios. Densification curves followed a third order polynomial relationship with height strain. Preform geometry significantly affected the densification curves and Poisson's ratio with density.
Injection Molding Simulation Analysis of Car Rim Using SolidWorks® PlasticsSheharyar Ghani
1. The document summarizes an analysis of injection molding parameters for a car rim using SolidWorks Plastics simulation software. PEEK polymer with 30% carbon fiber was used as the material.
2. Investigations were conducted on mold filling, packing, cooling, and costing. The number of gates and their location, melt temperature, and mold temperature were varied to study their effects on weld lines, shrinkage, and frozen layer thickness.
3. Increasing the number of gates or melt temperature increased weld lines and shrinkage, while higher mold temperatures decreased the frozen layer thickness. The simulations aimed to determine the most feasible design parameters before further analysis or manufacturing.
The document summarizes an experimental study that evaluated the effect of ferroboron content, welding current, and average welding speed on the microhardness of mild steel plates hardfaced using shielded metal arc welding with a ferroboron paste coating. Taguchi's method was used to design the experiment with three factors (ferroboron content, welding current, average welding speed) each at three levels. Microhardness tests found that microhardness increased with increasing ferroboron content and average welding speed, but decreased with increasing welding current. Analysis of variance identified ferroboron content as having the most significant effect on microhardness. The optimum parameters for maximum microhardness were determined to be 12 mg/mm2 ferro
In manufacturing, many products need to undergo increasing customisation, and a shortening of the manufacturing cycle time. This makes the time needed to produce prototypes one of the most important contributors to product development cycles. Rapid Prototyping (RP) offers the user the ability to optimise part design in order to meet customer requirements with few manufacturing restrictions. One of the most common RP processes is Laser Sintering (LS). A problem with LS is that sometimes the surface of the parts produced displays a texture similar to that of the skin of an orange (the so-called orange peel texture). This problem must be addressed before the technology can gain wider acceptance. The main aim of this research is to develop a methodology of controlling the input material properties that will ensure consistent and good quality of the fabricated parts. From the experiment, it was found that PA12 powder with high melt flow rate, low melting temperature, low glass transition temperature and low degree of crystallization temperature could improve the sintering process to produce a good Laser Sintering (LS) parts with lower shrinkage rate. The powder which has higher melt viscosity and lower melting heat becomes liquid more easily and therefore flows better during the sintering process due to a shorter chain molecular structure. The results of experimental work indicate that the melt viscosity, and part surface finish are correlated.
Synthesis and Mechanical Characterization of Aluminum-Graphene Metal Matrix b...dbpublications
The document summarizes research on synthesizing aluminum-graphene composites using powder metallurgy and characterizing the resulting material. Specifically, it discusses (1) creating aluminum composites with 0.1%, 0.2%, and 0.3% graphene through powder mixing and sintering, (2) analyzing the microstructure, hardness, and wear properties of the forged and unforged composites, and (3) concluding that the 0.1% graphene forged composite exhibited the best properties like highest hardness and lowest wear rate due to its high density and uniform graphene dispersion from forging.
This document discusses the effects of severe plastic deformation via equal channel angular pressing (ECAP) on an aluminum-titanium boride composite material. Key findings include:
1) Subjecting the composite to 2 passes of ECAP led to a 27.68% increase in tensile strength and 29% increase in hardness compared to the untreated composite.
2) The wear rate of the composite decreased with increasing sliding distance and increasing titanium boride content within the composite.
3) ECAP effectively refined the grain structure of the composite, leading to improvements in its mechanical properties like strength, hardness, and wear resistance.
The document describes an experimental study of the tribological properties of commercially pure titanium with different microstructures and coatings. The results show that titanium with an ultrafine-grained structure produced through severe plastic deformation has lower friction coefficient values and higher load-bearing capacity compared to coarse-grained titanium. Titanium samples coated with TiC using ion plasma spraying or TiO2 using microarc oxidation also exhibited lower friction coefficients than uncoated samples. The study provides data on friction coefficients and shear strengths of coated and uncoated titanium with different grain sizes.
A Study on Thermo-Mechanical Analysis of Hot Rolling & Estimation of Residual...IOSR Journals
The major problem in rolling process is the defects like fire cracks, severe sticking in a billet mill,
and etc. This paper deals with the study on reducing or minimizing the defects of rolling process. The analysis
has been carried out for different temperature i.e. 100°c, 150°c, 200°c, 250°c. As the temperature goes on
increasing correspondingly the residual stresses decreases. Hot rolling process helps in reduced residual
stresses at high temperature & helps in formation of smooth granular structure of product. Due to the symmetry
of the rolling components, half the model is built & the analysis is carried out with 4 roller sizes varying from
8mm to 20mm with 4mm increment & the results were tabulated by using ANSYS. This will helps in estimation
of residual stresses.
This document summarizes research on friction spot welding (FSpW) of carbon fiber-reinforced polyamide 66 laminate (CF-PA66). The researchers were able to produce CF-PA66 welds with good surface finishing and an absence of defects using FSpW. The welds achieved an average lap-shear strength of 26.8 MPa, comparable to ultrasonic welds of similar materials. Microscopy revealed distinct stir and thermomechanically affected zones in the welds. Holding pressure time during welding was important to control cooling and avoid surface flaws. This study demonstrated the feasibility of FSpW for joining carbon fiber composites.
This document summarizes a study that used Taguchi methods and Grey Relational Analysis to optimize drilling parameters for a composite material (Al-TiBr2). The study aimed to minimize surface roughness and maximize material removal rate during the drilling process. Experiments were conducted using an orthogonal array design with spindle speed, feed rate, and depth of cut as control parameters. Signal-to-noise ratios were calculated for each response and normalized. Grey relational coefficients and grades were then determined to identify the optimal drilling parameters. The results indicated that low spindle speed, high feed rate, and medium depth of cut provided the best combination for the multiple performance characteristics.
This document discusses the development and characterization of polymer-ceramic composite materials with continuous fiber reinforcement and functionally graded properties for aerospace applications. Specifically, it examines quartz fabric-reinforced composites with a silicone resin and fused silica powder matrix that is compositionally graded across the thickness. The composites demonstrated improved mechanical and thermal properties over non-graded materials, including high flexural strength, low thermal expansion, and the ability to withstand high heating rates without delamination or charring. The results suggest these functionally graded composites are promising candidates for reusable high-temperature aerospace structures.
The document summarizes research on solid-state recycling of light metals reinforced with inclusions through Equal Channel Angular Pressing (ECAP). It discusses how ECAP can be used to directly recycle metal scraps and chips to produce finished products with ultrafine grain microstructure and improved mechanical properties. The document reviews factors that influence the ECAP process like die angles, temperature, pressing speed and force. It also summarizes research on using ECAP to produce aluminum matrix composites reinforced with ceramic particles like silicon carbide, aluminum oxide, and boron carbide, and how this can enhance properties for applications.
IRJET- Experimental and Computational Simulation of CUZN37 Brass Alloy Proces...IRJET Journal
1) The document presents experimental and computational simulation of severe plastic deformation of CuZn37 brass alloy sheet using constrained groove pressing (CGP) with flat groove corrugated dies.
2) Both experimental and simulation results using AFDEX software showed that the effective strain and Brinell hardness of the alloy increased with increasing number of CGP passes up to the fourth pass, then slightly decreased in the fifth pass.
3) Microstructural analysis revealed that CGP led to the formation of non-uniform subgrains and refined the initial coarse grain structure of the alloy, resulting from dislocation behavior and the development of a deformed substructure.
Micro-Tensile Behavior of AA7020/Carbon Black Nanoparticle Metal Matrix Compo...researchinventy
The document summarizes research on the micro-tensile behavior of AA7020 aluminum alloy reinforced with carbon black nanoparticles. Finite element analysis was used to model composites with 3 different volume fractions of nanoparticles. The model predictions aligned well with experimental results in the elastic region but overestimated strength at higher stresses. Examination of fractured surfaces found nanoparticle-matrix debonding caused by localized stress concentrations. Elastic modulus increased with higher nanoparticle content according to rule of mixtures, finite element, and other models, though voids reduced properties. Tensile strength and von Mises stress also increased with nanoparticle volume fraction.
FORCE AND WEAR ANALYSIS OF PVD COATED CUTTING TOOL" - A REVIEWIJARIIE JOURNAL
The document reviews tribological properties of ternary nitride coatings used on cutting tools. It discusses how coatings like titanium aluminum nitride (TiAlN) and chromium nitride (CrN) exhibit improved tribological and mechanical properties over binary nitride coatings. The coatings provide benefits like high hardness, corrosion resistance, and oxidation resistance, enabling higher cutting forces and longer tool life. Scanning electron microscopy and scanning probe microscopy are used to examine the microstructure and properties of these coatings.
Modification of Recycled Al-332 Alloy Using Manganese DioxideIJERA Editor
Aluminum and its alloys are commercially available materials for both domestic (cooking utensils, beverages can) and industrial applications (automobile and aircraft structural parts). This study presented the effect of the use of manganese dioxide (MnO2), obtained from discarded dry cell batteries on the features and formation of pores in recycled pistons (Al-332 alloy). 3kg of recycled Al-332 alloy was obtained in form of ingot. 150 g of the ingot was re-melted and the molten alloy was treated with 2 to 12g of MnO2. The molten alloy was stirred gently for 1 minute, sand cast and normalized. Parts of the cast samples were used for microstructural analysis, tensile strength and hardness test following standard test procedures in accordance with ASTM E8M-91 standards (1992). The distribution of pores present in the cast alloys were studied using fractal analysis and spatial point pattern method (SPP). The hardness, tensile strength, average fractal dimensions and sphericities were related to the amount of MnO2. The micrographs revealed an absolute reduction in pores at 8gram addition of MnO2. Maximum hardness and tensile values of 50.8BHN and 65.01MN/m2 were obtained at 8 g addition of MnO2, above which there is decrease in properties of the material. The weighted average fractal dimension and sphericity for as-cast and sample treated with 8 g of MnO2 are 1.3276 and 0.3357; 1.0050 and 0.9918 respectively. Spatial point pattern revealed that the pores in the samples are randomly distributed.
Iaetsd fabrication and characterization of b4 cp particle reinforced lm24 al ...Iaetsd Iaetsd
This document describes research on fabricating and characterizing aluminum matrix composites reinforced with boron carbide (B4C) particles. LM24 aluminum alloy composites containing 1%, 2%, and 3% B4C by weight were produced using a compo casting method. Microstructural analysis found uniform distribution of B4C particles in the composites. Hardness and tensile tests showed the composites have superior mechanical properties compared to the unreinforced alloy, with hardness and tensile strength increasing with higher B4C content up to 3%. The composites were characterized using scanning electron microscopy and X-ray diffraction to analyze particle distribution and composition.
1. The document analyzes delamination in glass fiber reinforced epoxy plastic (GFRP) composite laminates of different orientations - [0/90/0], [0/60/0], and [0/45/0] - when drilled. Experiments were conducted drilling holes in GFRP plates of the three orientations at different cutting speeds and feed rates.
2. The maximum damaged area (delamination) after drilling was measured and used to calculate a delamination factor. Results showed that delamination factor depended on drill diameter, fiber orientation, and feed rate. Of the three orientations, [0/90/0] and [0/60/0] showed similar behavior with delamination decreasing
This document discusses the importance of grain size in materials and methods for producing ultrafine grain and nanomaterials. Decreasing grain size improves mechanical properties through increasing dislocations and grain boundaries. Severe plastic deformation techniques like equal channel angular pressing and high pressure torsion are used to refine grains down to the nanoscale in a top-down process. These nanomaterials exhibit high strength, ductility, and thermal stability due to their small, uniformly distributed grains.
Experimental Study Compared With American Code - ConcreteFilled – Double Skin...ijceronline
Six Specimens with three different volume fractions of steel fibers are cast and tested. Experiments on circular steel tubes in – filled with steel fiber reinforced concrete (SFRC) and normal concrete have been performed to investigate the contribution of steel fibers to the load bearing capacity of Short Composite Columns . The main variable considered in the test study is the percentage of steel. Fibers added to the in –filled concrete. All the specimens were tested under axial failure state realization. This project presents the percentage Variation in the compression strengths of the 3 types of Composite members taken under Study. The results show that 1.5% SFRC in filled steel columns exhibit enhanced ultimate load carrying compression until capacity. Experimental studies compared with American code
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document summarizes a study that evaluated the abrasive wear resistance of coatings deposited on 420 stainless steel substrates using the Twin Wire Arc Spray technique. The coatings were tested under dry and wet abrasive conditions according to ASTM standards using two different loads. The as-sprayed coatings and those subjected to tempering and cryogenic heat treatments were analyzed. Microstructural characterization found porosity of around 3.26% in as-sprayed coatings. Cryogenic treatment increased microhardness while tempering improved dry and wet abrasion resistance. Main wear mechanisms identified were splat delamination, plastic deformation, micro-cutting and fracture. The most severe wear in wet tests occurred on coating broadsides while dry
The Do Quick SS420 is a small clip-on MP3 player that supports common audio formats like MP3 and WMA. It has a built-in microphone for voice recording, plays for up to 13 hours on a single charge, and includes a pair of earphones. The mini player can be clipped onto clothing or bags for portable music playback and storage of lyrics, contacts, and notes.
The document provides information about AISI 420 stainless steel. It discusses the steel's composition of 12-14% chromium, heat treatment processes, mechanical properties, applications, and pricing. AISI 420 is a martensitic stainless steel that is hardened through heat treatment to a hardness of 50 HRC. It has good wear and corrosion resistance and is used for applications like knives, surgical instruments, and pump parts.
The document discusses different types of stainless steel, including their compositions and properties. It begins with an overview of crystallography and allotropes, explaining that iron and steel are crystalline and can exist in different forms. It then covers the four main types of stainless steel: ferritic, austenitic, martensitic, and duplex. For each type, the document describes their typical compositions in terms of chromium, nickel, and other elements, as well as their properties such as corrosion resistance, strength, and magnetic permeability.
Synthesis and Mechanical Characterization of Aluminum-Graphene Metal Matrix b...dbpublications
The document summarizes research on synthesizing aluminum-graphene composites using powder metallurgy and characterizing the resulting material. Specifically, it discusses (1) creating aluminum composites with 0.1%, 0.2%, and 0.3% graphene through powder mixing and sintering, (2) analyzing the microstructure, hardness, and wear properties of the forged and unforged composites, and (3) concluding that the 0.1% graphene forged composite exhibited the best properties like highest hardness and lowest wear rate due to its high density and uniform graphene dispersion from forging.
This document discusses the effects of severe plastic deformation via equal channel angular pressing (ECAP) on an aluminum-titanium boride composite material. Key findings include:
1) Subjecting the composite to 2 passes of ECAP led to a 27.68% increase in tensile strength and 29% increase in hardness compared to the untreated composite.
2) The wear rate of the composite decreased with increasing sliding distance and increasing titanium boride content within the composite.
3) ECAP effectively refined the grain structure of the composite, leading to improvements in its mechanical properties like strength, hardness, and wear resistance.
The document describes an experimental study of the tribological properties of commercially pure titanium with different microstructures and coatings. The results show that titanium with an ultrafine-grained structure produced through severe plastic deformation has lower friction coefficient values and higher load-bearing capacity compared to coarse-grained titanium. Titanium samples coated with TiC using ion plasma spraying or TiO2 using microarc oxidation also exhibited lower friction coefficients than uncoated samples. The study provides data on friction coefficients and shear strengths of coated and uncoated titanium with different grain sizes.
A Study on Thermo-Mechanical Analysis of Hot Rolling & Estimation of Residual...IOSR Journals
The major problem in rolling process is the defects like fire cracks, severe sticking in a billet mill,
and etc. This paper deals with the study on reducing or minimizing the defects of rolling process. The analysis
has been carried out for different temperature i.e. 100°c, 150°c, 200°c, 250°c. As the temperature goes on
increasing correspondingly the residual stresses decreases. Hot rolling process helps in reduced residual
stresses at high temperature & helps in formation of smooth granular structure of product. Due to the symmetry
of the rolling components, half the model is built & the analysis is carried out with 4 roller sizes varying from
8mm to 20mm with 4mm increment & the results were tabulated by using ANSYS. This will helps in estimation
of residual stresses.
This document summarizes research on friction spot welding (FSpW) of carbon fiber-reinforced polyamide 66 laminate (CF-PA66). The researchers were able to produce CF-PA66 welds with good surface finishing and an absence of defects using FSpW. The welds achieved an average lap-shear strength of 26.8 MPa, comparable to ultrasonic welds of similar materials. Microscopy revealed distinct stir and thermomechanically affected zones in the welds. Holding pressure time during welding was important to control cooling and avoid surface flaws. This study demonstrated the feasibility of FSpW for joining carbon fiber composites.
This document summarizes a study that used Taguchi methods and Grey Relational Analysis to optimize drilling parameters for a composite material (Al-TiBr2). The study aimed to minimize surface roughness and maximize material removal rate during the drilling process. Experiments were conducted using an orthogonal array design with spindle speed, feed rate, and depth of cut as control parameters. Signal-to-noise ratios were calculated for each response and normalized. Grey relational coefficients and grades were then determined to identify the optimal drilling parameters. The results indicated that low spindle speed, high feed rate, and medium depth of cut provided the best combination for the multiple performance characteristics.
This document discusses the development and characterization of polymer-ceramic composite materials with continuous fiber reinforcement and functionally graded properties for aerospace applications. Specifically, it examines quartz fabric-reinforced composites with a silicone resin and fused silica powder matrix that is compositionally graded across the thickness. The composites demonstrated improved mechanical and thermal properties over non-graded materials, including high flexural strength, low thermal expansion, and the ability to withstand high heating rates without delamination or charring. The results suggest these functionally graded composites are promising candidates for reusable high-temperature aerospace structures.
The document summarizes research on solid-state recycling of light metals reinforced with inclusions through Equal Channel Angular Pressing (ECAP). It discusses how ECAP can be used to directly recycle metal scraps and chips to produce finished products with ultrafine grain microstructure and improved mechanical properties. The document reviews factors that influence the ECAP process like die angles, temperature, pressing speed and force. It also summarizes research on using ECAP to produce aluminum matrix composites reinforced with ceramic particles like silicon carbide, aluminum oxide, and boron carbide, and how this can enhance properties for applications.
IRJET- Experimental and Computational Simulation of CUZN37 Brass Alloy Proces...IRJET Journal
1) The document presents experimental and computational simulation of severe plastic deformation of CuZn37 brass alloy sheet using constrained groove pressing (CGP) with flat groove corrugated dies.
2) Both experimental and simulation results using AFDEX software showed that the effective strain and Brinell hardness of the alloy increased with increasing number of CGP passes up to the fourth pass, then slightly decreased in the fifth pass.
3) Microstructural analysis revealed that CGP led to the formation of non-uniform subgrains and refined the initial coarse grain structure of the alloy, resulting from dislocation behavior and the development of a deformed substructure.
Micro-Tensile Behavior of AA7020/Carbon Black Nanoparticle Metal Matrix Compo...researchinventy
The document summarizes research on the micro-tensile behavior of AA7020 aluminum alloy reinforced with carbon black nanoparticles. Finite element analysis was used to model composites with 3 different volume fractions of nanoparticles. The model predictions aligned well with experimental results in the elastic region but overestimated strength at higher stresses. Examination of fractured surfaces found nanoparticle-matrix debonding caused by localized stress concentrations. Elastic modulus increased with higher nanoparticle content according to rule of mixtures, finite element, and other models, though voids reduced properties. Tensile strength and von Mises stress also increased with nanoparticle volume fraction.
FORCE AND WEAR ANALYSIS OF PVD COATED CUTTING TOOL" - A REVIEWIJARIIE JOURNAL
The document reviews tribological properties of ternary nitride coatings used on cutting tools. It discusses how coatings like titanium aluminum nitride (TiAlN) and chromium nitride (CrN) exhibit improved tribological and mechanical properties over binary nitride coatings. The coatings provide benefits like high hardness, corrosion resistance, and oxidation resistance, enabling higher cutting forces and longer tool life. Scanning electron microscopy and scanning probe microscopy are used to examine the microstructure and properties of these coatings.
Modification of Recycled Al-332 Alloy Using Manganese DioxideIJERA Editor
Aluminum and its alloys are commercially available materials for both domestic (cooking utensils, beverages can) and industrial applications (automobile and aircraft structural parts). This study presented the effect of the use of manganese dioxide (MnO2), obtained from discarded dry cell batteries on the features and formation of pores in recycled pistons (Al-332 alloy). 3kg of recycled Al-332 alloy was obtained in form of ingot. 150 g of the ingot was re-melted and the molten alloy was treated with 2 to 12g of MnO2. The molten alloy was stirred gently for 1 minute, sand cast and normalized. Parts of the cast samples were used for microstructural analysis, tensile strength and hardness test following standard test procedures in accordance with ASTM E8M-91 standards (1992). The distribution of pores present in the cast alloys were studied using fractal analysis and spatial point pattern method (SPP). The hardness, tensile strength, average fractal dimensions and sphericities were related to the amount of MnO2. The micrographs revealed an absolute reduction in pores at 8gram addition of MnO2. Maximum hardness and tensile values of 50.8BHN and 65.01MN/m2 were obtained at 8 g addition of MnO2, above which there is decrease in properties of the material. The weighted average fractal dimension and sphericity for as-cast and sample treated with 8 g of MnO2 are 1.3276 and 0.3357; 1.0050 and 0.9918 respectively. Spatial point pattern revealed that the pores in the samples are randomly distributed.
Iaetsd fabrication and characterization of b4 cp particle reinforced lm24 al ...Iaetsd Iaetsd
This document describes research on fabricating and characterizing aluminum matrix composites reinforced with boron carbide (B4C) particles. LM24 aluminum alloy composites containing 1%, 2%, and 3% B4C by weight were produced using a compo casting method. Microstructural analysis found uniform distribution of B4C particles in the composites. Hardness and tensile tests showed the composites have superior mechanical properties compared to the unreinforced alloy, with hardness and tensile strength increasing with higher B4C content up to 3%. The composites were characterized using scanning electron microscopy and X-ray diffraction to analyze particle distribution and composition.
1. The document analyzes delamination in glass fiber reinforced epoxy plastic (GFRP) composite laminates of different orientations - [0/90/0], [0/60/0], and [0/45/0] - when drilled. Experiments were conducted drilling holes in GFRP plates of the three orientations at different cutting speeds and feed rates.
2. The maximum damaged area (delamination) after drilling was measured and used to calculate a delamination factor. Results showed that delamination factor depended on drill diameter, fiber orientation, and feed rate. Of the three orientations, [0/90/0] and [0/60/0] showed similar behavior with delamination decreasing
This document discusses the importance of grain size in materials and methods for producing ultrafine grain and nanomaterials. Decreasing grain size improves mechanical properties through increasing dislocations and grain boundaries. Severe plastic deformation techniques like equal channel angular pressing and high pressure torsion are used to refine grains down to the nanoscale in a top-down process. These nanomaterials exhibit high strength, ductility, and thermal stability due to their small, uniformly distributed grains.
Experimental Study Compared With American Code - ConcreteFilled – Double Skin...ijceronline
Six Specimens with three different volume fractions of steel fibers are cast and tested. Experiments on circular steel tubes in – filled with steel fiber reinforced concrete (SFRC) and normal concrete have been performed to investigate the contribution of steel fibers to the load bearing capacity of Short Composite Columns . The main variable considered in the test study is the percentage of steel. Fibers added to the in –filled concrete. All the specimens were tested under axial failure state realization. This project presents the percentage Variation in the compression strengths of the 3 types of Composite members taken under Study. The results show that 1.5% SFRC in filled steel columns exhibit enhanced ultimate load carrying compression until capacity. Experimental studies compared with American code
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document summarizes a study that evaluated the abrasive wear resistance of coatings deposited on 420 stainless steel substrates using the Twin Wire Arc Spray technique. The coatings were tested under dry and wet abrasive conditions according to ASTM standards using two different loads. The as-sprayed coatings and those subjected to tempering and cryogenic heat treatments were analyzed. Microstructural characterization found porosity of around 3.26% in as-sprayed coatings. Cryogenic treatment increased microhardness while tempering improved dry and wet abrasion resistance. Main wear mechanisms identified were splat delamination, plastic deformation, micro-cutting and fracture. The most severe wear in wet tests occurred on coating broadsides while dry
The Do Quick SS420 is a small clip-on MP3 player that supports common audio formats like MP3 and WMA. It has a built-in microphone for voice recording, plays for up to 13 hours on a single charge, and includes a pair of earphones. The mini player can be clipped onto clothing or bags for portable music playback and storage of lyrics, contacts, and notes.
The document provides information about AISI 420 stainless steel. It discusses the steel's composition of 12-14% chromium, heat treatment processes, mechanical properties, applications, and pricing. AISI 420 is a martensitic stainless steel that is hardened through heat treatment to a hardness of 50 HRC. It has good wear and corrosion resistance and is used for applications like knives, surgical instruments, and pump parts.
The document discusses different types of stainless steel, including their compositions and properties. It begins with an overview of crystallography and allotropes, explaining that iron and steel are crystalline and can exist in different forms. It then covers the four main types of stainless steel: ferritic, austenitic, martensitic, and duplex. For each type, the document describes their typical compositions in terms of chromium, nickel, and other elements, as well as their properties such as corrosion resistance, strength, and magnetic permeability.
Hidro ÖZÇELİK is a Turkish company founded in 1997 that manufactures and exports hydraulic valves, pumps, and equipment. It has 25 employees and exports 90% of its production. The company focuses on research and development to introduce 5-10 new products yearly and provide customized solutions and support to customers worldwide across various industries. It has certification and sells to over 50 countries globally.
Se puede prevenir el transtorno del deficit de atencion e hiperactividad dura...67009651
Este documento teórico realiza una revisión de la psicopatología del trastorno por déficit atencional e hiperactividad (TDAH), el cual se manifiesta por dificultades crónicas en atención, impulsividad e hiperactividad que interfieren en el desarrollo del niño. El TDAH afecta entre el 3% y 15% de los niños y puede persistir hasta la edad adulta. Presenta comorbilidad con problemas de aprendizaje y conducta. Existe una multicausalidad que incluye factores
Se puede prevenir el transtorno de deficit de atencion e hiperactividad duran...67009651
El transtorno de deficit de atencion e hiperactividad es un trastorno de tipo neurológico que mas afecta a la población infantil en Colombia y el mundo entero, basado en varias investigaciones realizadas sus causas son de tipo genético, social, afectando la capacidad sicomotora del niño afectando la capacidad de concentracion del niño y problemas de conducta, se busca verificar con este problema de informacion si es posible ser detectado y tratado desde el inicio del embarazo
The document discusses the candidate's experience as a Product Developer for 6 months, where they learned that every project is unique due to different clients and design requirements. The candidate enjoys influencing the relationship between users and brands through strong design skills. They also learned about balancing creative vision with the limitations of designing for multiple products. The candidate has in-depth knowledge of 3D modeling software and enjoys learning new tools. Their education and work experience includes mechanical engineering, 3D modeling, tool design, prototyping, and programming.
Johannes Jacobus Britz is a qualified diesel mechanic with over 15 years of experience in vehicle repairs and maintenance. He has worked for several transport, workshop, and farming companies performing running repairs, service, and breakdown assistance on trucks, buses, heavy machinery, and farm equipment. Britz is currently employed temporarily at Blaaubank Farm helping with general maintenance and repairs. He has excellent health and references available from previous employers.
This document describes the author's country and city. The author is from Huesca, Spain which is located in the region of Aragón. The author also mentions their 12th century school, San Vicente, with an old facade.
O documento apresenta uma resenha de um livro sobre Ciência da Religião organizado por João Décio Passos e Frank Usarski. O livro aborda diversos temas relacionados à Ciência da Religião como epistemologia, história, fenomenologia, filosofia, ciências sociais e psicológicas da religião. A resenha destaca a abordagem dos organizadores em buscar legitimidade disciplinar para a Ciência da Religião e discute os diferentes capítulos do livro que tratam de objetos, métodos e teorias da
IRJET- Study of Fused Deposition Modeling Process Parameters for Polycarbonat...IRJET Journal
This document describes a study on the effects of process parameters on parts manufactured using fused deposition modeling (FDM) of a polycarbonate/acrylonitrile butadiene styrene (PC/ABS) blend material. Five parameters were selected - extrusion temperature, bed temperature, layer thickness, raster width, and printing speed. Experiments were conducted using an L8 orthogonal array design in Taguchi methodology. Parts were manufactured and measured for dimensional accuracy, surface roughness, and flatness without support structures. The goal was to determine optimal parameter settings to improve part quality characteristics for this material.
The document discusses various metal additive manufacturing techniques including powder bed fusion, directed energy deposition, binder jetting, and sheet lamination. Powder bed fusion techniques like selective laser melting use a laser to selectively fuse metal powder layers. Directed energy deposition techniques like laser engineered net shaping use a laser and metal powder or wire feedstock to deposit material. Binder jetting uses inkjet printing of a binder to join metal powder particles. Sheet lamination techniques like ultrasonic additive manufacturing bond metal foils using ultrasonic vibration. The document explores the process parameters, microstructures, and applications of these various metal 3D printing methods.
Synthesis of composite polymer for industrial applicationeSAT Journals
Abstract The Method of Fused Deposition Modelling is most popular rapid prototyping process producing parts layer by layer which is mainly made up of polymer. But the use of these parts is restricted because of low strength of plastic. To achieve efficient mechanical properties, metal composite polymer can be used which has not been used as feedstock material in FDM. Plastic component are most commonly produced by injection molding process. Wide variety of shapes and sizes of thin walled plastic parts are manufactured by this method . The aim of present study was to fabricate new metal composite and to investigate the effect of addition of metal powder on strength of polymer. As both FDM and Injection moulding are similar process the feasibility of metal composite feedstock was checked in injection moulding process. Experiments were carried out on parts produces by injection moulding process with different composition of metal and polymer. Six specimens with different proportions of aluminum and copper in polymer by weight were prepared as per the ASTM standard for Tensile and Flexural test. It can be concluded that addition of copper increases tensile strength of parts and aluminum increases bending strength of parts produced by Injection Moulding process. Key Words: Rapid Prototyping, Metal Composite polymer, Injection Moulding
Additive manufacturing (AM) refers to a process of building 3D objects by depositing material in layers based on a digital 3D design. Key differences between AM and subtractive manufacturing include part complexity, material options, speed, part quantity, and cost. Common AM techniques include stereolithography, fused deposition modeling, and selective laser sintering/melting. AM enables the production of parts with complex geometries and functionally graded materials not possible with conventional methods. Standard file format for AM is STL which represents the surface geometry of 3D models using triangular facets.
The document describes a study that uses finite element analysis and Taguchi's method to optimize the preform shape of a connecting rod forging. The goal is to minimize forging load and produce defect-free forgings. Finite element software was used to simulate hot forging of the connecting rod under different preform design parameters, including flash thickness, width, and radii. Taguchi's method was then applied to design parameter combinations to determine the most influential parameters. Through several optimization iterations, the optimal preform shape that gave minimum forging load and complete die filling was obtained. The approach aims to reduce design time and costs compared to traditional trial and error methods.
Design and Additive Manufacturing Considerations for Liquid Rocket Engine Dev...Nihar Patel
This document discusses the design and additive manufacturing considerations for developing a liquid rocket engine using 3D printing. It covers how initial engine design was constrained by the 3D printing process and requirements. Unexpected challenges during manufacturing required developing custom tools to machine parts and allow testing. The student team was ultimately able to complete a hot-fire testing campaign for their bi-propellant, 3D printed rocket engine.
A Review of FDM Based Parts to Act as Rapid ToolingIJMER
Fused Deposition Modeling (FDM) is one from basic Rapid Prototyping (RP) technologies
used in technical practice. In this contribution are presented basic information about parameters such
as layer thickness, part build orientation, raster angle, raster width and air gap. This study provides
insight into complex dependency of strength on process parameters. In this paper microphotographs
are used to show the mechanism of failure. The major reason for weak strength is attributed to
distortion within or between the layers.Developing a curved layer deposition methodology can
improve part quality by reduced lamination, reduction in the staircase effect which leads to improved
dimensional accuracy of the part. Less effort has been made to increase the range of FDM materials
to include metals or metal based composites with the help of metal based composite direct rapid
tooling will allow fabrication of injection moulding dies and inserts with desired thermal and
mechanical properties suitable for using directly in injection moulding machines for short term or
long term production runs
SPRING BACK PREDICTION OF SHEET METAL IN DEEP DRAWING PROCESSIAEME Publication
Spring back is one of the most significant phenomenon that affect the accurateness of the sheet metal parts. In order to obtain fixed tolerances for the formed parts it is highly recommended to use such process parameters/tool geometry that allow a considerably diminishing of the spring back amount. A Finite Element (FE) model is developed for the 2- D numerical simulation of sheet metal deep drawing process (Parametric Analysis) by using HYPERFORM with the appropriate material properties (anisotropic material) and simplifies boundary conditions
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
1) The study aims to optimize the shape of an aluminum billet to minimize forging load through finite element analysis.
2) An initial finite element model of the closed die forging process was created in ANSYS with the billet represented by finite elements.
3) The billet height-to-diameter ratio was identified as the design variable to be optimized, with the goal of minimizing forging load while limiting equivalent plastic strain to less than the fracture strain of 1.05.
Effects of Various Material Infiltrants in Sls Processtheijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation
1. The document summarizes a study on the effects of infiltrating stainless steel parts produced by selective laser sintering (SLS) with different materials, including bronze, brass, and bell metal.
2. Hardness, dimensional accuracy, bending strength, and surface roughness of the infiltrated stainless steel parts were evaluated. Bronze infiltration produced parts with the highest hardness while brass infiltration led to the best dimensional stability.
3. The study aims to determine the optimal infiltrant material for SLS stainless steel parts to improve mechanical properties and quality of final products.
A Review of FDM Based Parts to Act as Rapid ToolingIJMER
Abstract: Fused Deposition Modeling (FDM) is one from basic Rapid Prototyping (RP) technologies
used in technical practice. In this contribution are presented basic information about parameters such
as layer thickness, part build orientation, raster angle, raster width and air gap. This study provides
insight into complex dependency of strength on process parameters. In this paper microphotographs
are used to show the mechanism of failure. The major reason for weak strength is attributed to
distortion within or between the layers.Developing a curved layer deposition methodology can
improve part quality by reduced lamination, reduction in the staircase effect which leads to improved
dimensional accuracy of the part. Less effort has been made to increase the range of FDM materials
to include metals or metal based composites with the help of metal based composite direct rapid
tooling will allow fabrication of injection moulding dies and inserts with desired thermal and
mechanical properties suitable for using directly in injection moulding machines for short term or
long term production runs.
PARAMETERS OF FRICTION STIR PROCESSING ALONG WITH REINFORCEMENT OF COMPOSITIO...Journal For Research
This document summarizes a study on friction stir processing of an aluminium and tungsten carbide composite. The researchers varied the tool shoulder diameter between 16-20 mm while keeping other parameters constant. They found that a shoulder diameter of 18 mm produced the finest grain size and maximum tensile strength and microhardness. Smaller and larger diameters produced less heat, resulting in coarser grains and poorer properties. Microstructure analysis showed more uniform reinforcement particle dispersion with an 18 mm diameter tool.
The document discusses an experiment to determine the resolution limits of laser direct structuring (LDS) for producing circuit traces on molded thermoplastic components. In the experiment, patterns with varying trace widths and spacings were structured onto material samples using laser and then plated. Two scenarios were tested: 1) with no compensation for plating expansion, and 2) with traces structured narrower to compensate for expansion. The second scenario was more successful, with plated traces achieving target widths of 0.006, 0.008, and 0.010 inches without overplating across different materials. Trace widths as narrow as 0.006 inches with spacing of 0.006 inches were achieved on some materials using this compensation approach.
This document describes the conventional powder metallurgy process used to manufacture metal components. It involves three main steps: 1) mixing metal powders, 2) compacting the powders in a die under pressure, and 3) sintering the compacted shape in a furnace to bond the particles. Powder metallurgy offers advantages like net shape forming, tight tolerances, design flexibility, and low machining waste. The process is widely used in automotive and other industries to produce complex, high-precision parts in a cost-effective manner.
Parametric Analysis of Mild Steel Specimens Using Roller Burnishing ProcessIRJESJOURNAL
ABSTRACT:- Burnishing, a cold working process, is a very simple and effective method of improving surface properties, which can easily be carried out using existing machines, such as lathe. With changing trends in manufacturing industry, special attention is given on surface finish along with dimensional accuracy and tight geometrical tolerances. Burnishing comes in mind as one of popular finishing process because it is completely chip-less as compared to other finishing processes such as grinding, honing etc. The purpose of the research was to demonstrate burnishing process on ferrous metals namely mild steel alloy. Parametric analysis was done using speed and feed rate as input parameters and surface roughness & surface micro hardness as response variables. Burnishing was performed using Hindustan machine tools (HMT) power lathe (NH 26 model)
This document provides an overview of selective laser melting (SLM), also known as direct metal laser melting or laser powder bed fusion. SLM is an additive manufacturing technique that uses a high-power laser to fully melt metallic powders layer by layer into solid 3D parts. The document discusses the history and development of SLM, the SLM process, materials that can be used, benefits and applications of SLM, and concludes with references.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document summarizes an article that discusses optimizing the plate forming process using ANSYS parametric design language (APDL). Finite element analysis in ANSYS is used to simulate the plate forming process. The design variables considered are plate thickness, fillet radius, and depth of forming. The objective is to minimize the forming load. APDL allows building the finite element model parametrically to enable optimization. A series of optimization iterations are run to determine the optimal values for the design variables that result in the minimum required forming load. The material studied is an aluminum metal matrix composite reinforced with 15% silicon carbide particles.
Experimental Investigation of Impact Strength for ABS Plus F.D.M. Parts using...IRJET Journal
The document experimentally investigates the impact strength of parts made from ABS Plus material using Fused Deposition Modeling (FDM). It examines the effects of three FDM process parameters - model interior, build orientation angle, and direction of rotation - on impact strength. Experiments were conducted according to a Design of Experiments using Taguchi method. Analysis of variance was used to determine the most influential parameter on impact strength, which was found to be build orientation angle. Regression analysis estimated the percentage of error between experimental and predicted results. In summary, the document explores how FDM process parameters affect the impact strength of ABS Plus parts through experiments using Taguchi method.
Similar to Improving Structural Integrity with Boron-Based Additives for 3D printed 420 Stainless Steel (20)
2. 1, the areas presented in red are difficult to achieve with an AM process in general. More precisely, a
part requiring high structural integrity is not easy to produce using AM at the present time. A simple
solution to increase in the scale is to increase the working environment or to operate many machines in
parallel. However, the integrity requires the AM fabrication to make a product with the material
whose strength is comparable to the material produced in traditional manufacturing processes. This is
the major challenge within the AM community.
Figure 1: The Current Status of AM Processes among Manufacturing Processes
Because this paper will deals the integrity of the part produced by powder-based AM machine, we
will examine the type of the AM technique and the advantage of the particular system we address here.
Many types of powder-based AM systems are currently available. Such systems include, 3D printing
(3DP), selective laser sintering (SLS), selective laser melting (SLM) and electron beam melting
(EBM). These powder-based systems can be distinguished based on two consolidation methods: local
and uniform heating. Immediately, the local heating methods such as SLS, SLM and EBM are the
main source of inhomogeneity in AM parts. These methods may typically achieve a much higher final
density (although not reaching a theoretical density completely) because the material is melted and
consolidated with a heating source such as laser or electron beam. Then, during the printing process,
the consolidated material below is altered while the material above is consolidating. Therefore, the
microstructure is extremely non-uniform and sometimes the residual stresses can be too intense to
form cracks in the processed material. This problem can be mitigated by raising the temperature
during printing or heat-treating and/or hot-isostatic pressing (HIPing) afterwards to minimize these
detrimental defects as well as voids. 3DP is one of the few methods where a part can undergo uniform
heating, resulting in a more uniform final microstructure. However, the primary drawback of 3DP is
achieving the high relative density, thus the final material properties.
In most processes, the relative density of metallic green parts obtained by 3DP can reach about the
50-60% of a theoretical density. This result is much lower than the green compacts made via powder
metallurgy (P/M), which enables up to the 85% of a theoretical density (Allen and Sachs 2000, Farid
et al. 2008). In general, the density of a part made from 3DP is much lower than that made form P/M
technique. Thus, a post-processing step is necessary to improve the final density of a 3D printed part.
After 3D printing, a part is typically infiltrated with a low melting metallic material such as bronze
(Allen and Sachs 2000), which change the nature of the material while slightly improves the
mechanical properties such as elastic modulus, yield strength, hardness etc. by filling in the pores of
the printed material. Few other techniques for making high-dense homogeneous 3DP parts have been
published. One of them was the method of infiltrating transient liquid phase that combines through
diffusion with the skeletal material to form a desirable final composition (Lorenz et al. 2004). The
disadvantage of this infiltration method is that in increases the cost of the entire process. Kakisawa et
al. (2005) used fine carbonyl nickel powder (size 5μm) to print parts, and then sinter the parts in order
to reach 92% relative density.
Structural Integrity with Boron-Based Additives for 3D printed 420 Stainless Steel Do et al.
264
3. The static properties such as hardness, yield strength and elastic modulus of an AM part must
reach those of a traditionally processed part if they are expected to use in real applications. Moreover,
an AM part is noticeably lacking in its fatigue properties. Instead of the costly measurement of the
physical properties of the materials after AM, this paper examines the density of the sintered samples.
To make these samples, SS420 powder was mixed with various compounds as possible sintering aids
to improving the final density, which is the first step toward improving the integrity of 3DP parts. This
approach will lead us to make functional parts, also known as ‘direct digital manufacturing’ using the
powder-based system. One of few machines available in the current market that provide a uniform
consolidation condition is 3DP units manufactured by ExOne (N. Huntingdon, PA). This system
contains two powder beds: supply and print. The part building process for this device is based on
depositing layer by layer of powder while injecting a binder phase at the data points from the given
STL file. The required STL file can be created from the simple conversion of a CAD part file.
Our prior research (Sun et al. 2009) demonstrated the effectiveness of ceramic sintering aids for
enhancing sintered samples printed from 420 stainless steel. Silicon nitride powder was mixed with
stainless steel powder, which enabled us to attain a high relative density (~98%) and excellent
mechanical properties (near 200 GPa reported in (Budiniski, K. & Budiniski M. 1999)) sintering at
1300°C with slight distortion on the 3D printed part. However, because of the large amount of silicon
nitride (12.5wt% equivalent to 28% volume), the part may not have been considered to be a stainless
steel.
In order to reduce the amount of additive utilized, boron based powders including boron (B),
boron nitride (BN) and boron carbide (BC) were studied and compared. According to the phase
diagram of iron-boron (German and D’Angelo 1984), 1174o
C is the liquid-phase formation at eutectic
temperature (Figure 1). Its low melting temperature is advantageous because sintering was expecting
to take place at a low temperature. In P/M experiments, only 0.4wt% of boron was added to 316
stainless steel and sintered at 1240°C, which enabled them to achieve 99% density (Molinari et al.
1994). This study showed that boron based additives increased the density and decreased the sintering
temperature of printed parts significantly.
First, the densification test for many samples at different locations in the powder bed was
conducted to test the homogeneity of printed parts. To improve the surface finish, the small particles of
additives were aimed at filling in the gaps of the larger particles in order to increase surface quality.
Figure 2: Phase diagram of Iron - Boron
Structural Integrity with Boron-Based Additives for 3D printed 420 Stainless Steel Do et al.
265
4. 2 Experimental Processing
2.1 Materials and Sample Preparations
The spherical 420 SS powder (Exone, USA) was chosen for this study and it was used in all
experiments as the base powder. 420 SS has a particle size distribution range between 22 μm and 53
μm and with a mean size of 30 μm. Three additives, boron (B), boron carbide (BC) and boron nitride
(BN), were used as sintering aids, and their material specifications were provided in Table 1.
Table 1: Additives Material Specification
Material Provider
Average Particle Size
μm
Density
g/cm3
B Sigma Aldrich 1 2.34
BC Panadyne 0.6 2.51
BN Sigma Aldrich 1 2.29
For each sintering aid, three experiments were conducted with 0.5 wt%, 1.0 wt% and 1.5 wt% of
additive, with one additional comparison sample batch that contains no additives. During each
experiment (printing batch), 400 grams of powder mixture was measured and mixed. All powders
were measured using Adventurer AR 2140 (Ohaus Corp., Parsippany, NJ, USA) which has a
resolution of 0.0001g. A speed mixer DAC 150 (FlackTek, Inc., Landrum, SC, USA) was then used to
mix the powder mixture with angular velocity of 2000 rpm and 90 second per cycle for three times.
For the density and densification rate experiments, 9 cubic samples were printed with a dimension of 8
mm by 8 mm by 8 mm.
2.2 Materials and Sample Preparations
The printing process involved the use of the X1-Lab 3D printer. This machine operates through
the use of two beds: a supply bed and a print bed. Prior to the printing process, the supply bed is
lowered as far as it can and filled with the prescribed power mixture (Fig. 2). This ensures that the
machine can print as many layers as a design requires. The print bed, however, is raised to the top, so
the layers of powder can easily be moved onto it. Once the printing process has begun, a roller moves
a layer of power (0.1mm) from the supply bed and layers a layer to the print bed. The machine then
lays down a binder phase on top of the layer. Once the next layer is ready to be laid down, the supply
bed is raised, so the appropriate amount of powder is exposed, and the print bed is lowered, so the new
layer can easily be moved on to it. This process is repeated until the part is completed. In the printing
process, the amount of binder phase on each layer has to be controlled such that the layer can bind to
the previous layer to form a final shape of a part.
2.3 Density Variation
The deposition variation within the print bed was the first concern. This will result in the size
variation depending on the location of a part printed in the powder bed. To study this possibility, nine
small cubes were printed and the shrinkage on each cube were measured in a real time while sintering
using Thermomechanical Analyzer (TMA) (Setsys Evolution 18 (France)) under the protective
environment of argon gas. The final sintering temperature was set at 1400 °C for 6 hours with a
temperature rate of 10 °C/min for both heating and cooling cycles, and the final cooling temperature
was set at a room temperature.
Structural Integrity with Boron-Based Additives for 3D printed 420 Stainless Steel Do et al.
266
5. Figure 3: Schematics of 3DP Procedure
2.4 Sintering
The MRF (Materials Research Furnaces) environment-controlled furnace was used to sinter the
3D printed samples. The furnace utilized argon gas to avoid the oxidation. By extracting the gas in the
furnace before the sintering begins, the oxidation of the samples was prevented. For the experimental
process, the 3D printed samples were separated depending on the sintering temperature. The three
temperatures 1150°C, 1200°C, and 1250°C were chosen in this work. In order to reach the sintering
temperatures, the samples were places in the furnace and began the heating process starting at room
temperature. The furnace then began to heat samples to 240°C at a rate of 10°C/min. Once the furnace
reached 240°C, it was kept at this temperature for 2 hour to burn out the binder phase. The binder
phase consists of Ethylene Glycol Monobutyl Ether, Ethylene Glycol and Isopropanol which are
expected to burn out at the temperatures of 170°C, 197.3°C and 82.6°C, respectively. Thus, at 240°C,
these binder phase is completely burned out. Then, the furnace was heated to each prescribed
sintering temperature from 240°C at a rate of 5°C/min. Once the samples reached their prescribed
sintering temperature, they were kept at this temperature for 6 hours to complete the sintering process
of the samples. The samples were then cooled back down to room temperature at a rate of 10°C/min.
In order to calculate the relative density, the volume of each fully sintered piece was measured by
Archimedes’ principle using Adventurer AR 2140 (Ohaus Corp., USA), which has a resolution of
0.0001g.
3 Results and Discussion
3.1 Density Variation
Each printed cube was labeled 1~9, as shown in Figure 3 viewing from the top. During printing,
the overall layout was centered to the print bed and each part was spaced evenly; thus it was assumed
that cube 5 was the origin, (0,0). All other cubes were either 1 unit away in horizontal direction or
vertical direction or both, and their coordinates were assigned accordingly (ex. cube 1 was (-1,1)).
After the printing process, the printed samples are very close in the printed dimensions. In order to see
the density variation among these samples, the samples were sintered at 1400°C in our TMA.
All samples had similar densification profiles as shown in Figure 4. This is the densification of
the cube 1. Each profile was separated into two zones: zone 1 (heating and holding) and zone 2
(cooling). Figure 4 included both temperature (red line) and densification (green line) profiles during
the time span. The shrinkage starts at 1200°C and the shrinkage rate increases much faster when the
temperature reaches 1400°C. The samples continue to shrink in cooling process so we may increase
the density of the final sample by increasing the soaking time (6 hours).
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6. Figure 4: Top view of Printed Parts Layout for Each Batch
Zone 1: Heating and holding Zone 2: Cooling
Figure 5: Densification (Green) and Temperature (Red) Profile for cube 1
A correlation matrix (ranging form -1 to 1) was computed and shown in Table 2 to analyze the
relationship between the printed location of each cube and the correlation in shrinkage, both maximum
shrinkage and shrinkage at 1400 °C. Shrinkage was converted to positive value prior to the analysis. A
significant negative correlation between the shrinkage and horizontal direction indicated that
shrinkage increases as the location of cube moves to the left (negative direction); and near to zero
correlation between the shrinkage and vertical direction implied that vertical location was not a
significant factor for shrinkage. As the roller spread the power from the right side of power bed to the
left side, the right side of the powder bed had a higher compact factor since more powder exists at the
beginning (the right side) on each layer than at the end (the left side). Therefore, the parts printed on
the left side of the powder bed would experience more shrinkage as observed during TMA
experiment.
Table 2 Correlation Matrix of Shrinkage in Horizontal & Vertical Directions
Correlation in
Maximum
Shrinkage
Correlation in
Shrinkage at
1400 °C
Horizontal Direction -0.8205 -0.71688
Vertical Direction 0.052274 0.133584
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7. 3.2 Liquid Phase Sintering
Ea sample was polished using diamond polishing solution with the grit size of 1 μm for 30
minutes and etched with the solution made of 10 mL HNO3, 20mL HCl and 30 mL water for a few
seconds. Then it was examined under optical microscope to visualize the microstructure. Figure 5(a, b,
c) shows the microstructures of the samples with 0.5% of B additives sintered at 1150°C, 1200°C and
1250°C, respectively. Figure 5(b) shows that the samples sintered at 1200°C had liquid phase present
as powders started to group themselves compared to Figure 5(a) where the powders in their original
spherical shapes remained the same. Figure 5(c) shows the formation of much larger grains and grain
boundaries. It indicates that the grains have coalesced into larger grains. Figure 5(c) also shows
necklace microstructure between grains, indication of liquid phase sintering (Riegger, Pask and Exner
1980, Warren and Waldron 1972). Similar microstructure behavior can be observed in the samples
with the other two additives sintered at higher temperature, liquid phase sintering started to occur
based on the presence of the necklace microstructure.
(a) 0.5% B sintered at 1150°C (b) 0.5% B sintered at 1200°C (c) 0.5% B sintered at 1250°C
Figure 6: Microstructures of the Selected Sintered Samples.
3.3 Surface Quality
One of the important issues with 3D printing is the surface quality. Because of its characteristic
building process, the layering is evident on the side surfaces of the printed part. It improves little after
sintering. Using the bimodal-sized powder, Lanzetta and Sachs (2003) increase not only the density of
the sample (because the multiple powder sizes can increase the packing density) but also the surface
quality of the samples. However, sometime the mixing two diistinct powders is difficult. The slurry
method (Moon et al. 2000) is used with the bimodal powder because small particles are difficult to be
spread when they are dry and the amount of fine powder is more than 25%wt. However, this study
used only small amounts of fine additive powder and the high speed mixing process described in
Section 2.1 was very effective.
The surface roughness of each sample after sintering is measured by a Zeiss LSM 210 Confocal
Laser Scanning Microscope. Figure 6 shows the topography of three sintered samples at 1250°C with
0.5% boron carbide, 0.5% BN and pure stainless steel. The surface roughness decreases significantly
in the samples with the additives. Especially, the sample with 0.5% BC sintered at 1250°C formed
liquid phase and provide the smooth surface. The average roughness value, Ra, improve from 9.01 μm
with pure stainless steel to 8.2 μm with 0.5% BN and 6.22 μm with 0.5% BC.
50μm 50μm
100μm
(a) (b) (c)
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8. (a) BC (b) BN (c) Pure Stainless Steel
Figure 7: Topography of the Samples sintered at 1250C with 0.5 % wt additive of (a) BC, (b) BN
and (c) Pure Stainless Steel.
3.4 Densification
The SS420 powder samples were mixed with the 0.5%, 1% and 1.5% wt of the three additives, B,
BN and BC. Each of these samples was sintered at the temperatures of 1150°C, 1200°C and 1250°C.
The density of each sample after sintering was measured using the Archimedes principal. As shown in
Table 3, the additives did not necessary increase the density of the samples after sintering at 1150°C.
Raising the sintering temperature from 1150°C to 1200°C and 1250°C has increased the densities in
each case. For each sintering temperature, it was found that the samples with 1% wt B additives had
the highest densities. Among the samples with BN additives, the samples with 1% wt BN additive had
the highest densities. The highest relative density was attained with the sample with 1% wt B additive
at approximately 97%. There was a dramatic drop in the relative density from the 1% wt of B to the
1.5% wt of B at 1250°C because the latter sample formed extensive liquid phase during sintering.
With the presence of the extensive liquid phase, pores were generated, which were also observed in
(Moon et al. 2000). The liquid phase caused the distortion in the samples with 1.0% wt B and BC
additives at both 1200°C and 1250°C and the sample with 1.0% wt BN additives at 1250°C. The
samples with 1.5% wt of all additives sintered at 1250° have distorted the shape extensively. The
distortion is based on the observation of the shape of the cubic samples as presented in Figures 7 and
8. The sample with 0.5% wt of B additive sintered at 1250° was also distorted. The sample with 0.5%
wt of BN and BC sintered at 1250°C remained the same shape as shown in Figure 7 (a and b). The
sample with the highest density that maintains its shape was the 0.5% BC sample sintered at 1250°C
with a relative density of 90.22%.
Table 3: The Final Relative Densities After Sintering with and without the additives
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9. (a) 0.5% wt BC (b) 0.5% wt BN (c) Pure Stainless Steel
Figure 8: The Undistorted Samples After Sintering at 1250°C
(a) 1.5% wt B (b) 1.5% wt BN (c) 1.5% wt BC
Figure 9: The Distorted Samples After Sintering at 1250°C
4 Conclusions
The 3D printing and sintering process were used to make parts from SS420 stainless steel powder
with boron-based additives. The effect of additive contents and sintering temperature are studied on
the relative densities of the final parts.
(1) A slightly variation in the densification rate of samples depending on the locations in the print
bed. It can be explained by the variation in the powder packing as the roller moves from the right to
the left. More powder is present at the right side of the print bed during the powder spreading.
(2) The powder samples mixed with the smaller additives help to improve the final surface finish
substantially. Not only the smaller additives fill into the interstitial spaces among large particles but
also the additives enhance diffusion among the stainless steels powder.
(3) The highest dense obtained is 97% with the sample containing 1% B and sintered at 1250°C.
However, the sample was extensively distorted because of the extensive formation of liquid phase.
(4) The densest sample that maintained the original shape without distortion was the 0.5% wt BC
sintered at 1250°C at the relative density of 90.22%. Based on the result, the future work will
concentrate on fine-tuning the amount of additive around 0.5% and sintering temperature 1250°C.
(5) The extensive distortion is evident with B additive. By reducing the sintering temperature, the
use of B may improve the final shape.
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