Abstract:To further improve the mechanical properties of CuNiCoSi alloy through deformation combined with heat treatment, an annealed Cu-1.6Ni-1.2Co-0.6Si (mass ratio) alloy strip of 1 mm thick was processed with the steps of cold-rolling of different ratios, solution treatment, aging and further cold-rolling in this study. The effects of cold rolling before the solution treatment and after the aging on microstructure and properties of the alloy strip were studied. The results showed that the higher cold rolling ratio before the solution, the finer grain after solution, and this grain structure could be retained after aging and further slight cold rolling, which improved the strength of the alloy, while its toughening effect was not significant. The cold rolling after aging could further improve the strength of CuNiCoSi alloy strip, with little effect on the electrical conductivity, while plasticity of the alloy would be greatly reduced. By combining cold rolling, short-term solid solution, aging and final cold deformation, it was expected to obtain CuNiCoSi alloy strip with a yield strength ≥ 850 MPa and a conductivity ≥ 40%IACS (International Annealed Copper Standard).