Investigation of Strength and Electrical Conductivity in Cu–Ca Alloys

Abstract

Microstructure, electrical conductivity, and mechanical properties of aged Cu–Ca alloys were investigated. In Cu–0.1 at. ％Ca alloy and Cu–0.5 at.％Ca alloy after 90％ cold rolling, Cu₅Ca intermetallic phase was observed with about 1.3 µm and 4.5 µm in diameter in the Cu solid solution phase, respectively. By aging at 200, 300, and 400℃, the electrical conductivity increased, but the hardness significantly decreased, which was due to recovery and recrystallization. However, the higher the Ca content, i.e., the higher the volume fraction and larger the size of Cu₅Ca phase, the higher the softening resistance. In Cu–0.5 at.％Ca alloy, the tensile strength of 382 MPa and the electrical conductivity of 93％IACS were obtained after 90％ cold rolling. By aging at 200 or 300°C, the tensile strength and the electrical conductivity lie in the range of 266–382 MPa and 93–100％IACS, respectively.