Effect of plasma electrolytic polishing on the surface morphology and mechanical properties of CuCrZr porous structure fabricated by selective laser melting

Abstract

Due to the low laser absorption rate and high thermal conductivity of the copper alloy powder, results in poor surface quality of CuCrZr alloy porous structure fabricated by selective laser melting (SLM), which limits its research and application potential. Plasma electrolytic polishing (PEP) technology is a post-processing technology suitable for components with complex and fine structures. This study addresses the issue of a significant amount of unmelted powder adhering to the surface of SLM CuCrZr alloy porous structure, as well as the current inability of existing technologies to effectively handle such surface defects. CuCrZr alloy porous structures with a triple periodic minimal surface (TPMS) I-Wrapped Package (IWP) and Schwarz Package (SP) structures were prepared using SLM technology for plasma electrolytic polishing. The effect of the PEP on the surface quality and mechanical properties of CuCrZr alloy porous structure was investigated. The results indicate that the surface quality of the samples significantly improved after the PEP treatment. The weight of the samples continued to decrease with an increase in the polishing time, and the surface roughness of the porous structure stopped decreasing after reaching a certain degree. Surface morphology observations revealed that the two structures had different load-bearing capacity for the polishing time. The IWP structure experienced a partial fracture of the support rods after 32 min, while the SP structure did not show structural damage during the longest 42 min. The PEP treatment reduced the surface roughness of the CuCrZr porous structure without significantly changing its quasi-static behaviour.

Keywords

• Selective laser melting (SLM)
• CuCrZr alloy
• Porous structure
• Plasma electrolytic polishing
• Surface quality