Effect of heat treatments on microstructure, mechanical and electrical properties of Cu–Cr–Zr alloy manufactured by laser powder bed fusion

Copper–Chromium–Zirconium alloys are popular in the field of electronic materials because of their excellent electrical conductivity and good mechanical strength. However, it is still a challenge to manufacture Cu–Cr–Zr alloy parts through additive manufacturing. In this study, Cu–Cr–Zr alloy was processed by laser powder bed fusion (LPBF) and the optimal processing parameters were determined by monitoring the sample's density. To improve the strength and electric conductivity, the samples were undergone direct aging treatment from 400 °C to 620 °C. As the aging temperature increased, the tensile strength of the alloy increased firstly and then decreased. The electrical conductivity gradually increased with the aging temperature. After aging at 475 °C for 2 h, the tensile strength of the alloy reached 519.3 MPa, while keeping a good elongation of 15.5% and electrical conductivity of 78.7 %IACS. The theoretical calculation showed that the precipitates of Cr-enriched phases were the main reason for the increase in strength and electrical conductivity.