Abstract Cu-Cr-Nb-Ce alloy was fabricated by selective laser melting (SLM). The high-temperature stability of microstructure, mechanical properity and electrical conductivity of Cu-Cr-Nb-Ce alloy was studied by high-temperature heat treatment at 1 000 ℃. The results show that the matrix mocrostructure of the XY plane (perpendicular to the build direction) of the as-SLMed Cu-Cr-Nb-Ce alloy is composed of long columnar grains in the center of the molten pool and fine equiaxed grains distributed along the boundary of the molten pool. The two kinds of grains are staggered and the average grain size is 28.3 μm. The second phase are the nanoscale Cr2Nb phases dispersed in the matrix. After heat treatment at 1 000 ℃ for 10, 50 and 100 h, the overall morphology of the grains does not change obviously, but the grains grow and the average size of grain increases by 8.5%, 18.7% and 27.2%, respectively; The average size Cr2Nb phase grows from 29.5 nm to 348.6 nm, 524.9 nm and 589.4 nm respectively, and the maximum size reaches 1-3 μm. In addition, Cr2Nb phases in heat-treated specimens are more densely along the grain boundary. The hardness (HV) of the alloy decreases significantly from 126 to 84, 79 and 75 respectively; while the electrical conductivity increases significantly from 18.5%IACS to 54.6%IACS after heat treatment for 10 h, whereas no significant progress is observed with extension of the heat treatment time.
AI Yongkang,LIU Zuming,ZHANG Yazhou, et al. High-temperature stability of microstructure and properties of Cu-Cr-Nb-Ce alloy fabricated by selective laser melting[J]. Materials Science and Engineering of Powder Metallurgy, 2022, 27(5): 478-487.
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