CoTi precipitates: The key to high strength, high conductivity and good softening resistance in Cu-Co-Ti alloy

Highlights: • The precipitation sequence in the Cu-Co-Ti alloy was detected for the first time. • 480 MPa & 81% IACS were obtained in a novel Cu-Co-Ti alloy. • The strengthening and conductive mechanisms were systematically studied. • Low diffusion rate of Co in Cu induced a softening temperature of 600 °C. A novel Cu-Co-Ti alloy with high strength of 480 MPa, high conductivity of 81% IACS and excellent softening temperature up to 600 °C was fabricated via solid solution, cold rolling, and aging treatment. Various means were used to study the strengthening, conductive and anti-softening mechanisms of the alloys. It was detected that Co and Ti reacted and precipitated during the aging process. Both theoretical calculations and experimental results revealed that the solid solution scattering and precipitation strengthening were the dominant mechanisms that affected the electrical and mechanical properties of the alloy, respectively. While the high softening temperature of the alloy was mainly due to the coarsening of the precipitates was restricted by the diffusion rate of Co in the Cu matrix.