Preparation of Cu–Cr–Zr alloy by selective laser melting: Role of scanning parameters on densification, microstructure and mechanical properties

Abstract

The evolution of the microstructure and mechanical properties of Cu–Cr–Zr manufactured by selective laser melting (SLM) with different scanning parameters was studied. Accordingly, the Cu–Cr–Zr specimens with high relative density (99.5 ± 0.3%) were obtained by optimizing the scanning parameters and they also possessed the highest strength (280 ± 6 MPa) and ductility (23.4 ± 0.4%) compared to other SLM manufactured specimens. The crystallographic texture and the grain microstructure of the specimens for the horizontal and vertical planes all exhibit the same anisotropic trend, which is independent of the volumetric laser energy density and the defects in the specimen. The formation of twins in the specimen is mainly due to the combined effects of large residual stress, low stacking fault energy and intrinsic heat treatment. The Cr–Zr–Cu nano precipitates formed in the specimen can be attributed to the effect of intrinsic heat treatment during the SLM process. These twins and nano precipitates in the microstructure both contribute to the abovementioned excellent mechanical properties of SLM manufactured specimens.