Abstract:In this paper, the effects of deformation aging process on the microstructure, mechanical and electrical properties of Cu-xSc (x = 0.1, 0.2, 0.3, 0.4; mass fraction) alloys with different Sc contents were studied. The results showed that with the increase of Sc content, the grain size of Cu-xSc alloys matrix decreased gradually. The hardness of Cu-xSc alloy increased with the increase of Sc content, and the conductivity decreased with the increase of Sc content. Cu-xSc alloys with different Sc contents all reached the peak aging after aging at 400 ℃ for 60 min, so as to obtain a reasonable matching of hardness and conductivity. In order to further improve the strength and conductivity of the alloy, Cu-xSc alloys were subjected to two-step deformation aging treatment. It was found that a large number of deformation twins were generated in the matrix after two-step deformation aging, and the interaction between deformation twins and nano-precipitates significantly improved the mechanical and electrical properties of Cu-xSc alloys. The nano-phase precipitated before pre-aging would induce a large number of twin beams and high-density dislocations, which was beneficial to promote the precipitation of solid solution atoms during the final aging process, thereby improving the strength and conductivity of the alloy. After two-step deformation and aging, Cu-0.4Sc alloy had better matching of strength and conductivity. The tensile strength and conductivity of Cu-0.4Sc alloy were 656 MPa and 67.8%IACS, respectively, which were 20.6% and 18.7% higher than those of one-step deformation and aging.