Cu-Cr alloys with excellent mechanical and electrical properties have been used in many industrial fields. However, the weak heat resistance of Cu-Cr alloys is a considerable shortness. In this work, Cu-Cr-Ti alloy was fabricated by vacuum melting and plastic deformation. Mechanical property and electrical conductivity of Cu-Cr-Ti alloy were investigated after aging treatment. The results show that peak aging occurs when aging at 450 °C for 1 hour. The mechanism of performance changes are discussed. The softening temperature could be identified as 575 °C, according to percentage of hardness changes of peak-aged Cu-Cr-Ti alloy annealed at different temperature and time. The microstructure explained that the addition of Ti, which retards recrystallization, could enhance the softening resistance of Cu-Cr alloy.

Cu-0.5Cr (wt%) and Cu-0.5Cr-0.1Mg (wt%) alloys were manufactured in this study to analyse the relationship between the physical properties and microstructure under different states. Optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM) were used to observe the microstructures of the alloys following homogenization, hot-rolled, solid solution, cold-rolled and aging. The results showed that insoluble Cr phases existed in copper chromium and copper chromium magnesium alloys after holding at 925°C for 12 h for homogenization and hot rolling deformation of 80%, and Mg elements prevented the segregation of Cr phases at grain boundaries. After solution treatment by holding at 1000°C for 1 h, the mean grain size of both alloys were 299 nm and 81 nm, respectively, and the volume fraction of undissolved Cr phase was 0.4% and 0.2%, respectively. After 60 % cold deformation treatment, the hardness of the two alloys increased significantly as a result of the work hardening caused by the generation of dislocation. In the aging stage of 450°C for 1 h, lots of Cr precipitates were found in Cu-0.5Cr and Cu-0.5Cr-0.1Mg alloys, with a corresponding hardness of 162.8 HV and 170.1 HV and electrical conductivity of 82.9% IACS and 77.8% IACS, respectively.