Enhanced properties of nano-grained pure copper by equal channel angular rolling and post-annealing

The pure copper sample was severely plastically deformed by 8-pass equal channel angular rolling process. The thermal stability of processed copper was investigated by measuring the development of microhardness at isochronal annealing temperature. According to variation in microhardness, the recrystallization temperature of pure copper after 8 pass of equal channel angular rolling process was 230 °C. The influence of post-annealing on microstructure, mechanical and electrical properties of the 8-pass processed copper was investigated. Scanning electron microscopy micrographs and X-ray diffraction peak broadening analysis have demonstrated that grain size decreased with post-annealing, which is the reason for the increase in strength of the copper specimen. The electrical conductivity of sample increased after post-annealing because of the rearrangement of dislocations.

► The thermal stability was investigated by variation in hardness with temperature.
► The recrystallization temperature of the 8-pass ECAR processed copper was 230 °C.
► The XRD results showed decreasing in the crystallite size after annealing process.
► The strength of specimen with post-annealing has been improved about 15%.
► The elongation and electrical conductivity of samples improved after annealing process.