Excellent mechanical properties and high electrical conductivity of Cu-Co-Si-Ti alloy due to multiple strengthening

The high performance of copper alloys is widely welcomed due to their high electrical conductivity and excellent mechanical properties. These alloys are mainly used in electrical, electronic and aerospace fields. In the present work, we proposed a new class of Cu-Co-Si-Ti alloys by incorporating the multiple alloying elements, resulting in the multiple strengthening during heat treatment. It can be observed that Ti addition can significantly improve the micro-hardness of the Cu-Co-Si-alloy. Solution strengthening, deformation strengthening and dual-nanoprecipitation strengthening led to the Cu-Co-Si-Ti alloy with excellent tensile strength (617.9 MPa) and high electrical conductivity (41.7% IACS) using the optimal process of cold rolling by 50% and aging at 500 °C for 30 min. Electron backscatter diffraction technology was used to analyze the microstructure and texture evolution during the copper alloys aging process. It was found that the volume fraction of Goss, Brass, copper and S texture had close connections with the mechanical properties. From multiple strengthening mechanisms, the dual nanoprecipitation strengthening contributed the most due to the nanoprecipitation of Co2Si and Cu4Ti.