CALPHAD-based design and preparation of high-strength, high-conductivity Cu–Fe–Zr alloys

A novel precipitation strengthening Cu–Fe–Zr alloy was designed and prepared based on the results of calculation of the phase diagram. After solid solutionizing, rolling and aging at 450 °C for 1 h, the alloy had a tensile strength of 515 MPa and an electrical conductivity of 72% IACS. There were two kinds of precipitates in the alloy after aging at 450 °C for 1 h. Fe precipitates with an average diameter of 4.3 nm were present in the deformed grains. Fe2Zr precipitates with an average diameter of 29.1 nm were present in the recrystallized grains. Both the Fe and Fe2Zr precipitates had coherent interfaces with the Cu matrix. The precipitation kinetics and effects on the properties of the alloy were discussed. It is found that the cold rolling enhanced the driving energy of precipitation. The precipitation of Fe and Fe2Zr had a dominant effect on the increase in electrical and mechanical properties of the alloy.