Resistance to weakening after heating of copper alloys for conductors

1. For M1 copper the critical temperature with over 56% deformation is 150°C. The copper recrystallizes completely on heating at 250°C. 2. In their resistance to weakening the bronzes investigated are arranged in the following sequence: Cu−Cd, Cu−Ag, Cu−Mg, Cu−Cr, Cu−Zr. The Cu−Zr−Cr alloy had the highest resistance to weakening. 3. The substantial weakening on heating at 250°C after large deformation (∼90%) as compared with small deformation (17–56%) is no reason for giving up high degrees of deformation. These bronzes retain a high strength and high plasticity after heating at 250°C.