Study on the variation of properties of Cu–Cr–Zr alloy by different rolling and aging sequence

Abstract

The relationship between rolling-aging sequence and the microstructure evolution, mechanical-electrical properties of hot rolled-quenched Cu-0.67Cr-0.27Zr-0.12Ni-0.03Si-0.04Ti alloy was investigated in details and the underlying mechanism of the abnormal decrease in electrical conductivity of the peak-aged alloy by cold rolling was also revealed. The results indicated that a good combination of the tensile strength (585.5 MPa), yield strength (562.1 MPa), Vickers hardness (197.6 HV), and electrical conductivity (67.4 %IACS) was obtained in the Cu–Cr–Zr-based alloy by a sequence of peak aging at 450 °C for 2 h followed by 80% room-temperature rolling and then secondary aging at 400 °C for 1 h. Compared with the rolling-aging process, the strength improvement of the alloy by the aging-rolling-aging process was mainly dominated by dislocation density strengthening. Additionally, a decrease in electrical conductivity of the peak-aged alloy after cold rolling was attributed to the re-dissolution and the refinement of partial coherent precipitates.