High strength Co-Cr-Mo alloy by hot isostatic pressing of powder

Currently available cobalt alloy prostheses for total hip applications are fabricated by investment casting techniques. Instances of stem fracture have been reported due to metal fatigue secondary to stem loosening or cement breakdown. A new process has been developed which includes the preparation of ultraclean powder and subsequent consolidation of the powder by hot isostatic pressing. The resultant solid material is characterized by 100 percent density and ultrafine grain size. Prostheses prepared by the new process have the same biocompatibility and corrsion resistance as the conventional cast alloy but higher strength and fatgue resistance.