Microstructure and properties of aging Cu-Cr-Zr alloy

The crystallography and morphology of precipitate particles in a Cu matrix were studied using an aged Cu-Cr-Zr alloy by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The tensile strength and electrical conductivity of this alloy after various aging processes were tested. The results show that two kinds of crystallographic structure associated with chromium-rich phases, fcc and bcc structure, exist in the peak-aging of the alloy. The orientation relationship between bcc Cr precipitate and the matrix exhibits Nishiyama-Wasserman orientation relationship. Two kinds of Zr-rich phases (Cu4Zr and Cu5Zr) can be identified and the habit plane is parallel to {111}(Cu) plane during the aging. The increase in strength is ascribed to the precipitation of Cr- and Zr-rich phase.