New high-strength, high-conductivity Cu-Ag alloy sheets

A sheet-conductor fabrication method has been developed for Cu-Ag alloys containing 6–24 wt% Ag in which high-strength and high-conductivity are obtained by coldworking combined with intermediate heat treatments. The intermediate heat treatments were repeated three times at 400–450°C for 1–2 h at appropriate stages of cold-rolling. The optimized Cu-24wt% Ag alloy sheet with a 96% reduction ratio shows an ultimate tensile strength of 1050 MPa and an electrical conductivity of 75% IACS at room temperature. Anisotropy in the strength with respect to the rolling direction is less than 10%, and no anisotropy in the electrical conductivity occurs. We demonstrated to be able to manufacture the Cu-Ag sheets for Bitter magnet on a commercial basis. The sheets fabricated by this method are promising as conductors for high-field Bitter magnet coils.