An Investigation on Mechanical and Electrical Behavior of Pure Copper Produced by Equal Channel Angular Pressing

Equal channel angular pressing (ECAP) is considered to be the most promising severe plastic deformation route to receive ultrafine grained materials with high strength and good physical properties. Mechanical properties, electrical conductivity and electrical erosion of commercial pure copper rod processed by ECAP were investigated. For this purpose a set of ECAP dies with the intersecting channel angle of 90 and an external arc of curvature of 37º and punch was design and manufactured. Commercially pure copper was processed through ECAP die up to 8 passes. The mechanical experiments indicated that the yield stress increased with increasing the number of passes till the 5th one, but beyond this pass a little decrease was observed. The trend of electrical conductivity changes is different from the yield stress of the material, in a way that electrical conductivity will gradually decrease to the fifth passes. After which electrical conductivity will increase slightly. Also for the first time electrical erosion of pure copper processed by ECAP during the electrical discharge processes were investigated. It was found that, with increasing the number of passes and finer grains of pure copper, electrical erosion decrease with respect to NON-ECAP copper in the same testing conditions.