Abstract
? 2022 Elsevier B.V.In this study, we investigate the influence of grain boundary character on isothermal phase transformation and mechanical properties of selective laser melting (SLM) fabricated Co-Cr-Mo alloy. The grain boundary engineering (GBE) was used to manipulate the isothermal phase transformation and precipitation. The As-SLM Co-Cr-Mo and GBE Co-Cr-Mo alloys were isothermal treatment at 800 ℃ for 6 h in a muffle furnace, followed by air cooling, respectively. It was found that the high density of stacking faults and low-angle boundaries in As-SLM Co-Cr-Mo alloy accelerated the phase transformation of γ-Co to ε-Co and Laves phase precipitation, which improved the tensile strength and drastically deteriorated the ductility. While, the high fraction of twin boundaries in GBE Co-Cr-Mo alloy retard the isothermal phase transformation and improve the resistance to Laves phase precipitation, which nearly maintain the high mechanical performance after the same isothermal treatment. The results of this study can be a guide to fabricate high-performance Co-Cr-Mo alloy according to work conditions.
NSTL
Elsevier