Selective laser melting of Cu–Cr–Zr copper alloy: Parameter optimization, microstructure and mechanical properties

Abstract

The combination of selective laser melting (SLM) and Cu-based alloys has attracted attention in recent years due to the increasing requirements for components characterized by complicated structures and high electrical and thermal conductivity. In this paper, to investigate the forming properties of a Cu–Cr–Zr alloy in SLM, a statistical model regarding the impacts of the processing parameters on the density was established via an experimental approach (response surface method and analysis of variance). Furthermore, based on the acquired optimal processing parameters, samples with nearly full density and standard tension specimens were fabricated, and their microstructures and mechanical properties were analyzed. X-ray diffraction results indicate that the phase composition of the as-built sample by SLM contains only α-Cu phase and the Bragg peaks of the α-Cu phase in SLMed sample distinctly differs from those of powders and of wrought copper alloy. Compared with wrought copper alloy, SLMed Cu–Cr–Zr shows a comparable ultimate tensile strength (∼321 MPa); however, its elongation at break (25%) is much higher than that of wrought sample (15%). In addition, according to electron back-scattered diffraction analysis, a strong texture with respect to the <110> direction parallel to the building direction arose during SLM process.