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

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.

2015 ◽  
Vol 1125 ◽  
pp. 504-508
Author(s):  
M.F. Fazira ◽  
M.H.A. Hamid ◽  
Ahmad Nizam bin Abdullah ◽  
Mazlan Mohamad ◽  
Yuichi Otsuka

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.


Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 422
Author(s):  
Kuai Zhang ◽  
Yungang Li ◽  
Hongyan Yan ◽  
Chuang Wang ◽  
Hui Li ◽  
...  

An Fe/FeAl2O4 composite was prepared with Fe-Fe2O3-Al2O3 powder by a hot press sintering method. The mass ratio was 6:1:2, sintering pressure was 30 MPa, and holding time was 120 min. The raw materials for the powder particles were respectively 1 µm (Fe), 0.5 µm (Fe2O3), and 1 µm (Al2O3) in diameter. The effect of sintering temperature on the microstructure and mechanical properties of Fe/FeAl2O4 composite was studied. The results showed that Fe/FeAl2O4 composite was formed by in situ reaction at 1300 °C–1500 °C. With the increased sintering temperature, the microstructure and mechanical properties of the Fe/FeAl2O4 composite showed a change law that initially became better and then became worse. The best microstructure and optimal mechanical properties were obtained at 1400 °C. At this temperature, the grain size of Fe and FeAl2O4 phases in Fe/FeAl2O4 composite was uniform, the relative density was 96.7%, and the Vickers hardness and bending strength were 1.88 GPa and 280.0 MPa, respectively. The wettability between Fe and FeAl2O4 was enhanced with increased sintering temperature. And then the densification process was accelerated. Finally, the microstructure and mechanical properties of the Fe/FeAl2O4 composite were improved.


2015 ◽  
Vol 1112 ◽  
pp. 519-523 ◽  
Author(s):  
Jarot Raharjo ◽  
Sri Rahayu ◽  
Tika Mustika ◽  
Masmui ◽  
Dwi Budiyanto

Observation on the effect of adding titanium oxide (TiO2) and magnesium oxide (MgO) on the sintering of α-alumina (Al2O3) has been performed. In this study, technical alumina used as basic material in which the sample is formed by the pressureless sintering/cold press and sintered at 1500°C which is lower than alumina sintering temperature at 1700°C. Elemental analysis, observation of microstructure, hardness, fracture toughness and density measurements were carried out to determine the physical and mechanical properties of alumina. The results indicate a change in the microstructure where the content of the platelet structure are much more than the equilateral structure. At sintering temperature of 1500°C, neck growth occurs at ceramics grain, supported by the results of the density test which indicate perfect compaction has occurred in this process.


2013 ◽  
Vol 589-590 ◽  
pp. 572-577 ◽  
Author(s):  
Hua He Liu ◽  
Han Lian Liu ◽  
Chuan Zhen Huang ◽  
Bin Zou ◽  
Ya Cong Chai

Al2O3-MgO, Al2O3-Y2O3 and Al2O3-MgO-Y2O3 composite ceramics were fabricated respectively by hot-press sintering technique. With the analysis of the mechanical properties and microstructure, it was found that single additive MgO could be more favorable to the grains’ refinement and densification than Y2O3; the composite additive including both MgO and Y2O3 was better than single additive MgO or Y2O3, because their interactions could improve the mechanical properties of the Al2O3 ceramics; The sintering temperature could be reduced by adding the suitable amount of composite additives.


2007 ◽  
Vol 46 (9-10) ◽  
pp. 449-453 ◽  
Author(s):  
Yonglin Yan ◽  
Yong Zheng ◽  
Haijun Yu ◽  
Haijian Bu ◽  
Xin Cheng ◽  
...  

2012 ◽  
Vol 455-456 ◽  
pp. 650-654 ◽  
Author(s):  
He Yi Ge ◽  
Jian Ye Liu ◽  
Xian Qin Hou ◽  
Dong Zhi Wang

The physical and mechanical properties of nanometer ZrO2-ZrO2fiber composite ceramics were studied by introduction of ZrO2fiber. ZrO2composite ceramics at different sintering temperature was investigated by porosity and water absorption measurements, flexual strength and thermal shock resistance analysis. Results showed that ZrO2composite ceramics containing 15 wt% ZrO2fiber with sintering temperature of 1650°C exhibited good mechanical properties and thermal shock resistance. The porosity and the water absorption were 8.84% and 1.62%, respectively. The flexual strength was 975 MPa and the thermal shock times reached 31 times. Scanning electron microscope (SEM) was used to analyze the microstructure of ZrO2composite ceramics.


2015 ◽  
Vol 75 (7) ◽  
Author(s):  
Amir Arifin ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Junaidi Syarif

Hydroxyapatite (HA) has been widely used in biomedical applications due to its excellent biocompatibility. However, Hydroxyapatite possesses poor mechanical properties and only tolerate limited loads for implants. Titanium is well-known materials applied in implant that has advantage in mechanical properties but poor in biocompatibility. The combination of the Titanium alloy and HA is expected to produce bio-implants with good in term of mechanical properties and biocompatabilty. In this work, interaction and mechanical properties of HA/Ti6Al4V was analyzed. The physical and mechanical properties of HA/Ti6Al4V composite powder obtained from compaction (powder metallurgy) of 60 wt.% Ti6Al4V and 40 wt.% HA and sintering at different temperatures in air were investigated in this study. Interactions of the mixed powders were investigated using X-ray diffraction. The hardness and density of the HA/Ti6Al4V composites were also measured. Based on the results of XRD analysis, the oxidation of Ti began at 700 °C. At 1000 °C, two phases were formed (i.e., TiO2 and CaTiO3). The results showed that the hardness HA/Ti6Al4V composites increased by 221.6% with increasing sintering temperature from 700oC to 1000oC. In contrast, the density of the composites decreased by 1.9% with increasing sintering temperature. 


Author(s):  
Md Mehtab Alam and B.S Motgi

The paper deals with detailed study on microstructure and mechanical properties of aluminum 7068 reinforced with fly ash and silicon carbide by powder metallurgy, aluminum 7068, silicon carbide and fly ash were taken in powder form of required size and mixed together in varying proportion according to specification and compacted with pressure of 400MPa using hydraulic press to make samples and then samples were sintered at 600°c for 2 hours, the samples were tested for density, compressive strength, hardness and microstructure was analyzed using scanning electron microscope, energy dispersive x-ray study was carried out in order to confirm presence of silicon carbide and fly ash in aluminum matrix.


Author(s):  
I Aatthisugan ◽  
Aishik Banerjee ◽  
Mohammed Moinuddin Hasan ◽  
Aditya Singh Patel ◽  
Kumar Pushkar ◽  
...  

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