Selective laser melting of CuCrZr alloy: processing optimisation, microstructure and mechanical properties

Abstract

The effect of process parameters on the densification behaviour and microstructural characteristics of CuCrZr alloy processed by selective laser melting (SLM) was systematically investigated. The effect of laser power and scanning speed on the surface morphology of the samples with single track fabricated by SLM was investigated. Additionally, the bulk samples were produced to investigate the influence of the scanning strategy on the densification level. The coupled model of the effect of process parameters on relative density was established by response surface methodology (RSM) and experiment. The process parameters were optimized to obtain almost fully dense CuCrZr samples with a relative density close to 99.57%. The microstructural analysis demonstrated the presence of stable melt tracks without obvious porosity. The grain morphology and orientation are highly correlated with laser trajectory and construction direction. The samples present obvious cellular and columnar structures. The XRD results show that, apart from the diffraction peaks of α-Cu, the diffraction peaks of other phase components were not detected. Finally, the ultimate tensile strength of 338 MPa, yield strength of 216 Mpa and elongation of 42.4% were achieved for the SLMed CuCrZr parts.

Keywords

• Selective laser melting
• Response surface methodology
• Relative density
• Microstructure
• Mechanical properties