Selective laser melting of Cu–Ni–Sn: A comprehensive study on the microstructure, mechanical properties, and deformation behavior

Abstract

A comprehensive understanding of the deformation behavior and strengthening mechanism of the selective laser melted (SLM) alloy is critical in reaping the complete potential of the SLM process. Accordingly, this work focuses on the influence of SLM on the microstructure, deformation behavior, and mechanical properties of the Cu–Ni–Sn alloy compared with their cast (CC) counterparts. An equiaxed-columnar bimodal structure with dispersed γ particles was observed due to the rapid solidification conditions, which helps in eliminating the otherwise formed brittle dendrite structure. The unique SLM microstructure with increased dislocation density offers a superior combination of tensile strength and ductility that is much higher than the CC samples. The SLM microstructure involving dislocation cells and fine precipitations led to a relatively high strain rate sensitivity (0.012 ± 0.002) and a small activation volume (~115 b3). It has been observed that in the as-prepared SLM material the strength contribution comes mainly from grain refinement, dispersed precipitation, and increased dislocation density.