摘要

The selective laser melted (SLM) CoCrWMo alloys were solution treated at 1 200 ℃ for 1 h, and then aged at 600, 700, 750, 800 and 900 ℃ for 10 h respectively. The effects of solution-aging treatment on the microstructure and properties of the alloy were studied. The results show that the SLM CoCrWMo alloy is composed of FCC γ phase and HCP ε phase martensite. The transformation from γ phase (FCC phase) to ε phase (HCP phase) occurs during solution- aging treatment. The content of ε phase martensite increases with increasing the aging temperature, M23C6(M=Cr,Mo,W) precipitated at the same time. In the alloy aged at 750 ℃, the proportion of ε phase is 77%, indicating that aging treatment can promote the transformation of FCC→HCP martensite. The microhardness of all aged alloys is significantly higher than that of solid solution alloys. The strength of the alloy aged at 750 ℃ is improved while the elongation is taken into account, the tensile strength and yield strength are 1 076 MPa and 820.8 MPa respectively, and the elongation reaches 10.5%. ? 2020, Editorial Office of Materials Science and Engineering of Powder Metallurgy. All right reserved.