Effect of trace alloying elements on the stress relaxation properties of high strength Cu–Ti alloys

Abstract

Modern electronic components put forward higher requirements for copper-based alloys, hoping to have high elastic properties and stress relaxation resistance. The addition of Fe increased the dislocation density, tensile strength, and the number of deformed bands after cold rolling. After cold rolled by 94% and aged at 450 °C for 5 min, the hardness, tensile strength, and elongation of the CuTiCrMg–Fe alloy was 448 HV, 1610 MPa and 4.75%, respectively. Adding Fe can improve the stress relaxation resistance of samples, and the stress relaxation rate of the CuTiCrMg–Fe alloy was 14.7% after loading at 200 °C for 100 h. The stress relaxation process of Cu–Ti alloys is mainly divided into the dislocation's reaction stage and dislocations and precipitates' interaction stage. These findings have important implications for the development of Cu–Ti alloys with high strength and high-stress relaxation resistance.