Effect of Sintering Temperature on Density, Hardness and Strength of MIM Co30Cr6Mo Biomedical Alloy

抄録

This paper reports on the effect of sintering temperature on the density, hardness and strength of Co30Cr6Mo fabricated by Metal Injection Molding (MIM). Palm stearin and polyethylene have been used as the binder system. The feedstock was injected by injection molding machine to produced micro dumbbell shape part. The specimens were solvent debound in n-hepthane for 15 minutes and thermally debound in argon atmosphere for an hour. The sintering was carried out in vacuum furnace at temperature 1250 °C, 1300 °C and 1350 °C for an hour. The density, hardness and tensile strength were then measured. The specimens that have been sintered at 1350 °C showed highest density and tensile strength compared with samples sintered at 1250 °C and 1300 °C. The samples which has been sintered at 1350 °C has highest relative density (93 %), compared with the same sample sintered at 1250 °C (87 %) and 1300 °C (76 %). As the temperature increased, the tensile strength increased gradually 400 MPa to 700 MPa and the micro hardness also increased from 200 Hv to 540 Hv. The morphology of sintered specimen showed that the morphological bonding between powder particles becomes denser at highest sintering temperature of 1350 °C.