Excellent Mechanical Properties and High Electrical Conductivity of Cu-Co-Si-Ti Alloy Due to Multiple Strengthening

Abstract

High performance copper alloys are widely used in electrical, electronic, aerospace fields welcomed due to their high electrical conductivity and excellent mechanical properties. At present work, we proposed a new class of Cu-Co-Si-Ti alloy by incorporating the multiple alloying elements, resulting in the multiple strengthening during heat treatment. The achievement of solution strengthening, deformation strengthening and dual-nanoprecipitation strengthening leaded to the Cu-Co-Si-Ti alloy with excellent tensile strength (617.9 MPa) and high electrical conductivity (41.7% IACS) by the optimum process of 50% cold rolling and aging at 500 °C for 30 min. EBSD was used to analyze the microstructure and texture evolution during the aging process. Moreover, it was found that the volume fraction of Goss, Brass, copper and S texture had close connections with the mechanical properties. By comparing with the contributions of multiple strengthening mechanisms, dual-nanoprecipitation strengthening contributed quite a lot due to the nanoprecipitation of Co2Si and Cu4Ti.