Effect of nickel content on the processing and microstructure evolution of Co-Cr-Mo-Ni alloys

摘要

Two type cobaltchromiummolybdenumnickel (Co-Cr-Mo-Ni) alloys were prepared by the powder metallurgy technology. The effect of the element powder nickel content on the milling process and then the microstructure evolution and mechanical properties of the sintered alloys was examined. The increase of the element powder Ni promotes the work harden of the product powders and then decreases the porous defects of the sintered samples. With the increase of the nickel content, the morphology of the sintered alloys changes from coarsely nonuniform grains to finer equiaxial grains with fault striations and the phase changes from single hcp phase to a dual phase of hcp and fcc structure. Obvious improvements in the tensile strength and uniform plastic elongation are achieved in the high nickel alloy. The elongation of the low nickel alloy decreases while that of the high nickel alloy increases with the raw powder milling time.