Microstructure and Properties of Forged CoCrMo Alloy for Load Bearing Application

2015 ◽  
Vol 1125 ◽  
pp. 504-508
Author(s):  
M.F. Fazira ◽  
M.H.A. Hamid ◽  
Ahmad Nizam bin Abdullah ◽  
Mazlan Mohamad ◽  
Yuichi Otsuka
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Rupture Strength ◽  
Processing Technique ◽  
Zinc Stearate ◽  
Cocrmo Alloy ◽  
Load Bearing ◽  
Biomedical Implant ◽  
Different Temperatures ◽  
Microstructure Density

CoCrMo alloy are known to be widely applied as biomedical implant materials. They have been practically used for artificial knee joints and hips. This is due to their excellent corrosion and wear resistances as well as good mechanical properties and biocompatibility. This published work is a research to improve the tensile properties of the alloy for load bearing application. This approach is an innovative process that will enhance the mechanical properties of the materials against the conventional processing technique while reducing the number of steps and energy consumption in producing the final parts; hence more economical. Grain refinement is expected to promote significant enhancement in both properties. Preforms are prepared through powder metallurgy route prior to the low strain rate upset forging process. The alloy powder was mixed with zinc stearate as a binder at different milling times. The formulated powder is compacted and then sintered at different temperatures. Characterization of the sintered parts are studied on their microstructure, density, hardness and transverse rupture strength (TRS). Further characterization was done using transmission electron microscopy (TEM) to study the grain refinement in enhancing the properties of the material.

Sintering Effects on the Microstructure and Mechanical Properties of CoCrMo Alloy

2016 ◽  
Vol 1133 ◽  
pp. 259-263 ◽  
Author(s):  
Mohd Hasnan Abdull Hamid ◽  
Fazira Suriani Mohamed Fadzil ◽  
Mohd Asri Selamat ◽  
M.A. Ahmad
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Rupture Strength ◽  
Physical And Mechanical Properties ◽  
Hydraulic Press ◽  
Zinc Stearate ◽  
Knee Joints ◽  
Cobalt Chromium ◽  
Cocrmo Alloy ◽  
Microstructure And Mechanical Properties

Cobalt chromium molybdenum (CoCrMo) alloy is widely used in artificial hip and knee joints because of their excellence corrosion and wear resistance, as well as good mechanical properties and biocompatibility. This study investigates the effect of sintering temperature on the microstructure and mechanical properties of CoCrMo using powder metallurgy technique. CoCrMo powder was mixed with zinc stearate and then put into the shaker mixer at 65 rpm for 3 hours. The powder was then compacted at a pressure of 18T using an automated hydraulic press and sintered at a temperature in the range of 1200 – 1400 °C under 95 Vol% N2/ 5 Vol% H2atmosphere. The microstructure, physical and mechanical properties of the samples are analyzed using scanning electron microscopy (SEM), Vickers’s microhardness tester and transverse rupture strength (TRS). The study reveals that the density, hardness and strength of CoCrMo samples increase as sintering temperature increases.

Consolidation and Mechanical Properties of Mechanically Alloyed Al-Mg Powders

2008 ◽  
Vol 1128 ◽  
Author(s):  
Mira Sakaliyska ◽  
Sergio Scudino ◽  
Hoang Viet Nguyen ◽  
Kumar Babu Surreddi ◽  
Birgit Bartusch ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Nanocrystalline Structure ◽  
Hot Extrusion ◽  
High Strength ◽  
Processing Route ◽  
Compression Tests ◽  
Mechanically Alloyed ◽  
Different Temperatures ◽  
Microstructure Density

AbstractNanostructured Al-Mg bulk samples with compositions in the range of 10 – 40 at.% Mg have been produced by consolidation of mechanical alloyed powders. Powders with composition Al90Mg10 and Al80Mg20 were consolidated into highly dense specimens by hot extrusion. Room temperature compression tests for the Al90Mg10 specimen reveal interesting mechanical properties, namely, a high strength of 630 MPa combined with a plastic strain of about 4 %. The increase of the Mg content to 20 at.% increases the strength by about 100 MPa but it suppresses plastic deformation. The Al60Mg40 powder was consolidated at different temperatures by spark plasma sintering and the effect of the sintering temperature on microstructure, density and hardness have been studied. The results reveal that both density and hardness of the consolidated samples increase with increasing sintering temperature, while retaining a nanocrystalline structure. These results indicate that powder metallurgy is a suitable processing route for the production of nanocrystalline Al-Mg alloys with promising mechanical properties.

scholarly journals Enhancement of Fluidity and Mechanical Properties of Al – Si cast Alloy

2019 ◽  
Vol 9 (2) ◽  
pp. 246-251
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Copper Content ◽  
Cast Alloy ◽  
Base Material ◽  
Testing Conditions ◽  
Weight Percentage ◽  
Grain Sizes ◽  
Casting System ◽  
Different Temperatures

The aim of the study is to investigate the fluidity and mechanical properties of the Al-Si alloy by varying the copper content at three different temperatures with the effect of grain refinement. In this present examination a humble endeavour has been made to know the properties with an ease strategy for sand casting system. Al- Si aluminium alloy is chosen as the base material and copper powder; grain refinement and scrap were added as the compositions. The investigation has been furnished by variying the weight percentage of copper (0-4%), scrap (20-40%) and grain refinement (0-0.4%). Test examples were exposed to various testing conditions and properties have been upgraded. The tensile strength of the material increases with increase of percentage of copper content and the fluidity is balanced by addition of grain refinement. The comparison between microstructure images at 0% copper and 4% copper shows the variation of grain sizes.

Mechanical Properties and Aging Behavior of Ultrafine Grained Al-Ag Alloy Fabricated by Accumulative Roll-Bonding

2014 ◽  
Vol 794-796 ◽  
pp. 851-856
Author(s):  
Tadashiege Nagae ◽  
Nobuhiro Tsuji ◽  
Daisuke Terada
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Accumulative Roll Bonding ◽  
Precipitation Hardening ◽  
Tensile Elongation ◽  
Solution Treatment ◽  
High Strength ◽  
Subsequent Aging ◽  
Roll Bonding ◽  
Ultrafine Grained

Accumulative roll-bonding (ARB) process is one of the severe plastic deformation processes for fabricating ultrafine grained materials that exhibit high strength. In aluminum alloys, aging heat treatment has been an important process for hardening materials. In order to achieve good mechanical properties through the combination of grain refinement hardening and precipitation hardening, an Al-4.2wt%Ag binary alloy was used in the present study. After a solution treatment at 550°C for 1.5hr, the alloy was severely deformed by the ARB process at room temperature (RT) up to 6 cycles (equivalent strain of 4.8). The specimens ARB-processed by various cycles (various strains) were subsequently aged at 100, 150, 200, 250°C, and RT. The hardness of the solution treated (ST) specimen increased by aging. On the other hand, hardness of the ARB processed specimen decreased after aging at high temperatures such as 250°C. This was probably due to coarsening of precipitates or/and matrix grains. The specimen aged at lower temperature showed higher hardness. The maximum harnesses achieved by aging for the ST specimen, the specimens ARB processed by 2 cycles, 4 cycles and 6 cycles were 55HV, 71HV, 69HV and 65HV, respectively. By tensile tests it was shown that the strength increased by the ARB process though the elongation decreased significantly. However, it was found that the tensile elongation of the ARB processed specimens was improved by aging without sacrificing the strength. The results suggest that the Al-Ag alloy having large elongation as well as high strength can be realized by the combination of the ARB process for grain refinement and the subsequent aging for precipitation hardening.

The influence of gadolinium on Al–Ti–C master alloy and its refining effect on AZ31 magnesium alloy

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenxue Fan ◽  
Hai Hao
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Master Alloy ◽  
Cast Alloy ◽  
Az31 Magnesium Alloy ◽  
Synthesis Mechanism ◽  
Refining Effect ◽  
Master Alloys

Abstract Grain refinement has a significant influence on the improvement of mechanical properties of magnesium alloys. In this study, a series of Al–Ti–C-xGd (x = 0, 1, 2, 3) master alloys as grain refiners were prepared by self-propagating high-temperature synthesis. The synthesis mechanism of the Al–Ti–C-xGd master alloy was analyzed. The effects of Al–Ti–C-xGd master alloys on the grain refinement and mechanical properties of AZ31 (Mg-3Al-1Zn-0.4Mn) magnesium alloys were investigated. The results show that the microstructure of the Al–Ti–C-xGd alloy contains α-Al, TiAl3, TiC and the core–shell structure TiAl3/Ti2Al20Gd. The refining effect of the prepared Al–Ti–C–Gd master alloy is obviously better than that of Al–Ti–C master alloy. The grain size of AZ31 magnesium alloy was reduced from 323 μm to 72 μm when adding 1 wt.% Al–Ti–C-2Gd master alloy. In the same condition, the ultimate tensile strength and elongation of as-cast alloy were increased from 130 MPa, 7.9% to 207 MPa, 16.6% respectively.

scholarly journals Biological Applications of Severely Plastically Deformed Nano-Grained Medical Devices: A Review

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 748
Author(s):  
Katayoon Kalantari ◽  
Bahram Saleh ◽  
Thomas J. Webster
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Bacterial Colonization ◽  
Antibiotic Use ◽  
Bone Cell ◽  
Corrosion Properties ◽  
Biomedical Implant ◽  
Specific Strength ◽  
Biological Functionality ◽  
Bone Cell Proliferation

Metallic materials are widely used for fabricating medical implants due to their high specific strength, biocompatibility, good corrosion properties, and fatigue resistance. Recently, titanium (Ti) and its alloys, as well as stainless steel (SS), have attracted attention from researchers because of their biocompatibility properties within the human body; however, improvements in mechanical properties while keeping other beneficial properties unchanged are still required. Severe plastic deformation (SPD) is a unique process for fabricating an ultra-fine-grained (UFG) metal with micrometer- to nanometer-level grain structures. SPD methods can substantially refine grain size and represent a promising strategy for improving biological functionality and mechanical properties. This present review paper provides an overview of different SPD techniques developed to create nano-/ultra-fine-grain-structured Ti and stainless steel for improved biomedical implant applications. Furthermore, studies will be covered that have used SPD techniques to improve bone cell proliferation and function while decreasing bacterial colonization when cultured on such nano-grained metals (without resorting to antibiotic use).

scholarly journals Microstructure of Al-5Cu-1Li-0.6Mg-0.5Ag-0.5Mn Alloys

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Wenzheng Chen ◽  
Wenlong Zhang ◽  
Dongyan Ding ◽  
Daihong Xiao
Keyword(s):  
Mechanical Properties ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Aging Treatment ◽  
Corrosion Current ◽  
Homogenization Temperature ◽  
Tafel Polarization ◽  
Al2cu Phase ◽  
Different Temperatures ◽  
Microstructural Optimization

Microstructural optimization of Al-Li alloys plays a key role in the adjustment of mechanical properties as well as corrosion behavior. In this work, Al-5Cu-1Li-0.6Mg-0.5Ag-0.5Mn alloy was homogenized at different temperatures and holding times, followed by aging treatment. The microstructure and composition of the homogenized alloys and aged alloys were investigated. There were Al7Cu4Li phase, Al3Li phase, and Al2CuLi phases in the homogenized alloys. The Al7Cu4Li phase was dissolved with an increase in homogenization temperature and holding time. Al2Cu phase and Al2CuLi phase coarsened during the homogenization process. The alloy homogenized at 515 °C for 20 h was subjected to a two-stage aging treatment. Peak-age alloy, which had gone through age treatment at 120 °C for 4 h and 180 °C for 6 h, was mainly composed of α-Al, Al20Cu2Mn3, Al2CuLi, Al2Cu, and Al3Li phases. Tafel polarization of the peak-age alloys revealed the corrosion potential and corrosion current density to be −779 mV and 2.979 μA/cm2, respectively. The over-age alloy had a more positive corrosion potential of −658 mV but presented a higher corrosion current of 6.929 μA/cm2.

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