Micro-Nanostructured High-Strength and High-Conductivity Cu0.9Cr0.1Zr Alloy Prepared by C-ECAP, Cryogenic Rolling, and Aging

Abstract:

The Cu0.9Cr0.1Zr alloy was deformed through continuous equal channel angular pressing (C-ECAP) through Route A, followed by liquid nitrogen cryogenic rolling (CR) and aging treated at 450 °C. The microstructure, mechanical properties, and conductivity of the alloy were detected by electron back-scattered diffractometer, energy dispersive spectroscope, X-ray diffractometer, scanning electron microscope, and transmission electron microscope. The evolution mechanism of the texture during the deformation process and its influence on mechanical properties were analyzed. The results show that directional shear bands form in the CuCrZr alloy during the C-ECAP process, and the preferred orientation of the microstructure is consistent with the rolling direction. After deformation, the number of precipitated phases (mainly Cr) increases with the prolongation of aging time, accompanied by the appearance of micro-nanostructured fibrous structure in the alloy. After C-ECAP for three passes, 75% CR deformation, and aging at 450 °C for 2 h, the tensile strength, microhardness, and conductivity reach 538 MPa, 168 HV, and 80%IACS, respectively. CR, aging heat treatment, and formation of recrystallization texture are all conducive to the improvement of conductivity.