Effect of Ag addition on the microstructure and mechanical properties of Cu-Cr alloy

Abstract

Effect of Ag addition on the microstructure and mechanical properties of as-cast, cold-rolled and aging treated Cu-Cr alloys were investigated in this study. The results indicated that adding a small amount of Ag significantly improve the mechanical properties of the Cu-Cr alloys with little effect on electrical conductivity. Besides the solution strengthening mechanism of Ag, the distribution changes of Cr precipitates from the chain along grain and dendritic boundaries to homogeneously dispersed sphere in the as-cast Cu-Cr-Ag alloys, and more fibrous Cr precipitates obtained in the cold-rolled Cu-Cr-Ag alloys also played key roles in the performance improvement of the alloys. By intermediate frequency induction melting with non-vacuum melting condition, 1000 °C − 60 min solution treatment, 95% cold-rolling deformation, and 400 °C − 90 min aging treatment, the Cu-0.89Cr-0.44Ag alloy exhibited excellent mechanical-electrical properties with the tensile strength of 541.5 MPa and electrical conductivity of 83.2%IACS. Meanwhile, the Cu-0.94Cr-0.11Ag alloy showed a better cost performance (tensile strength*conductivity/raw material price per kg) about 800 MPa*%IACS/Yuan. These relevant results provided important references for research and development of the high-performance Cu-Cr-Ag alloy.