EBSD analysis of nano-structured copper processed by ECAP

Highlights: → The effectiveness of different deformation routes has been evaluated with the 120o die. In terms of HAGBs generation, the efficiency is on the order of B60 ∼ B45 > B30 ∼ A > BC. → Considering diameter of grains, the effectiveness of grain refinement in the 120o die is on the order of B45 > B60 > B30 > BC > A. → The effectiveness in producing nano-grain is on the order of B60 > B45 > B30 > A > BC. - Abstract: 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 deg., 30 deg., 45 deg., 60 deg. and 90 deg. between each ECAP pass designated as routes A, B30, B45, B60 and BC, 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 deg. die in terms of grain refinement was in the order of B45 > B60 > B30 > A > BC. 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 BC > A > B60 > B30 > B45.