Microstructure evolution and properties of a Cu–Cr–Zr alloy with high strength and high conductivity

Abstract

Effects on microstructure evolution, mechanical and electrical properties of a Cu–Cr–Zr–Ni–Si–Ti alloy via multi-stage rolling and aging were investigated in details. The results showed that the optimal comprehensive performance of tensile strength (649 MPa) and electrical conductivity (65.5 %IACS) was obtained by three-stage rolling and aging (primary 80% room-temperature rolling (RTR) and aging at 450 °C for 2 h + secondary 60%RTR and aging at 300 °C for 1 h + tertiary 50%RTR and at 150 °C aging for 1 h). Through the microstructure characterization, it was found that the orientation relationship between the precipitates and Cu matrix was (001)Cu //(001)Cr //(001)Ni2Si, [011]Cu //[011]Cr //[010]Ni2Si in the investigated Cu–Cr–Zr–Ni–Si–Ti alloy. The increase of yield strength was primarily attributed to fine grain strengthening and precipitation strengthening, and secondly attributed to dislocation strengthening. This work will provide a guideline for the fabrication of high-performance copper alloys.