Low Strain Rate Upset Forging of Preformed CoCrMo Powder Alloy for Load Bearing Application: A Review

CoCrMo alloy are known to be widely applied as biomedical implant materials. They have been used for artificial hip and knee joints because of their excellent corrosion and wear resistances as well as good mechanical properties and biocompatibility. Although as-cast or annealed CoCrMo alloys are frequently subjected to practical use, there are possibilities to exhibit insufficient mechanical properties due to coarse microstructure and solidification defects that often lead to premature failure of implants. Therefore, the review suggested that an improvement of tensile properties as well as fatigue properties shall be made for further mechanical reliability by applying low strain rate upset forging. Grain-structure or grain-flow optimization is a sufficient area to be studied to produce parts with enhanced mechanical properties, impact strength, and fatigue endurance limits. Forgings deliver strengths were the most needed while maintaining a good balance of 3-demensional properties. By optimizing grain-flow characteristics during the forging process, we should be able to tailor the directional strength, which permits forging to meet the requirements of the parts with the desired configurations.