Lattice structures of Cu-Cr-Zr copper alloy by selective laser melting: Microstructures, mechanical properties and energy absorption

Abstract

Characterized by high thermal-electrical conductivity and reasonable specific strength, lattice structures of copper alloy have great potential in industrial applications. However, they have been rarely studied due to their complicated structures and difficulty in fabrication. Based on the ability of selective laser melting to produce near net shape parts with any complex geometry directly, Cu-Cr-Zr copper alloy lattice structures with high density were manufactured and studied for the first time. A series of lattice structures were designed by a mathematical approach named Triply Periodic Minimal Surfaces and their mechanical properties, microstructures and deformation behaviors were systematically studied. The effects of cell size and volume fraction on their mechanical properties and energy absorptions were analyzed and evaluated. The results demonstrate that the mechanical and energy absorption properties of the lattice structures varied dramatically with the changes of cell size and volume fraction. Due to the good plasticity of the copper alloy, stress-strain curves of the lattice structures exhibit a long stress plateau without stress collapses, which is very beneficial for energy absorption. The deformation of the lattice structures occurred uniformly and was caused by the struts bending without cell breaking and struts fracturing.