Nano-grained pure copper with high-strength and high-conductivity produced by equal channel angular rolling process

► Equal channel angular rolling was successfully applied to fabricate nano-grained pure copper strip. The following conclusions are drawn. ► Nano-grained pure copper was obtained by ECAR process. The grain size was measured using SEM micrographs. And it was about 70-200 nm after 10 passes. It concluded that ECAR process can be useful to reach nano-grain in pure copper. ► Tensile test showed that the yield strength significantly increased after the first pass followed by a gradual increase with further increase in pass up to 7-pass, while tensile strength did not experience much variation. The maximum strength has been obtained at 7-pass and further deformation declined it. Also ECAR process causes to significant reduction of elongation. A good combination of high yield strength and moderate ductility was obtained in 7-pass ECAR'ed pure copper. ► Results showed an increase in microhardness by a factor of approximately 1.7 at the first two passes. It followed by almost constant value up to seventh pass, after all, by subsequent passing, microhardness slightly decreased. ► Electrical conductivity of samples decreased with increasing the number of ECAR passes. This was true as far as 7 passes, after 7 passes electrical conductivity slightly increased. In addition electrical conductivity of ECAR'ed copper is higher than that in alloyed counterpart. ► After ECAR process, high-strength and high-conductivity commercial pure copper can be obtained. Although the reduction in elongation limits some applications of copper.