EBSD analysis of nano-structured copper processed by ECAP

► The effectiveness of different deformation routes has been evaluated with the 120° die. In terms of HAGBs generation, the efficiency is on the order of B 60 ∼ B 45 > B 30 ∼ A > B C. ► Considering diameter of grains, the effectiveness of grain refinement in the 120° die is on the order of B 45 > B 60 > B 30 > B C > A. ► The effectiveness in producing nano-grain is on the order of B 60 > B 45 > B 30 > A > B C. In this study, copper was processed by equal channel angular pressing (ECAP) up to twenty passes at room temperature to obtain a mixture of submicron and nano-grained structure under different deformation routes. As the cross sections of the specimens were circular, the deformation routes were varied by rotating bars through 0°, 30°, 45°, 60° and 90° between each ECAP pass designated as routes A, B 30, B 45, B 60 and B C, respectively. In order to study the orientation of the elongated crystallites, EBSD analysis was carried out and tensile tests were used to evaluate mechanical properties. The EBSD data were analysed for a statistical characterization of the deformed matrix. The effectiveness of different deformation routes with a 120° die in terms of grain refinement was in the order of B 45 > B 60 > B 30 > A > B C. The mixing of ultrafine grains with nanocrystalline grains resulted in a combination of high strength and high elongation to failure after twenty pass ECAP with different routes at room temperature. The effectiveness of the five different routes in elongation was B C > A > B 60 > B 30 > B 45.