Stabilizing the Microstructure of Additively Manufactured Low-C Co-28Cr-6Mo Alloy

Co-28Cr-6Mo alloy is widely used in aerospace industry and biomaterial engineering where high demands are placed on material strength, fatigue endurance as well as corrosion resistance. As complex shapes and weight savings are required for such components, additive manufacturing is the ideal production way. For example, Selective Laser Melting (SLM) of metallic powders is capable of achieving complex components with fine details. However, Co-28Cr-6Mo alloy prepared by SLM shows a characteristic microstructure which causes its instability at elevated temperatures that can occur during operation. To eliminate such operational problem, the component must be appropriately heat-treated. This paper demonstrates the instability of Co-28Cr-6Mo alloy prepared by SLM and proposes the heat treatment yielding its stabilization.