Microstructures and electrical-mechanical properties of Cu-Cr-Zr and Cu-Cr-Zr-Ti alloys heat-treated in hydrogen

Abstract

The effect of hydrogen heat treatment on the electrical and mechanical properties of Cu-0.2Cr-xZr (x = 0, 0.15, 0.6, 1.2) and Cu-0.2Cr-0.6Zr-0.5Ti alloys was investigated. After hydrogen heat treatment, Cu5Zr precipitates decomposed with the formation of ZrH2 and TiH 2. For the Cu-Cr-Zr ternary alloys, high conductivity (i.e., >90% IACS) was achieved in Cu-0.2Cr-0.15Zr alloy after hydrogen heat treatment at 450°C while maintaining high tensile strength, more than 450 MPa. Compared with the properties of hydrogenated Cu-0.2Cr-0.6Zr and Cu-0.2Cr-0.6Zr-0.5Ti alloys, adding Ti to the Cu-Cr-Zr alloys with hydrogen heat treatment was effective in improving tensile strength. The alloy properties achieved after hydrogen heat treatment at 400°C for 5 h were 665 MPa and 56% IACS.