Study on Microstructure and Properties of Cu-0.77Cr-0.078Zr-0.13Ag Alloy

The microstructure evolution and properties of Cu-0.77Cr-0.078Zr-0.13Ag alloy under various processes were investigated by SEM, EDS, TEM. The results show that the tensile strength, electrical conductivity, and elongation of Cu-0.77Cr-0.078Zr-0.13Ag alloy after hot forging, aging, and cold rolling is 640 MPa, 80.8 % IACS and 8%, respectively. There are large drop-like Cr-rich phases and smaller size granular Cr-rich phases in the as-cast structure. The size of the Cr-rich phases reduces after hot forging, and distributed in granular and long strips. Cold rolling after treatment, the grains are uniformly distributed in the rolling direction, with the thickness of 300-500 nm. The Cr-rich phases are mainly distributed in the grains and at the grain boundaries in the form of granules, and the middle boundary is densely distributed and the size is below 300 nm. In addition, Zr and Ag elements are always dispersed in the alloy, large number of dislocation entanglement exists in the matrix after alloy cold rolling treatment, and the crystal structures of the nanoscale Cr phases are fcc and bcc.