Cyclic Deformation Response of ARBed Copper with Composite- natured Ultra-fine- Microstructures and its Comparison with Cyclic Deformation Response of ECAPed Copper

Abstract

The composite microstructure found in ARBed materials has yielded cyclic softening and cyclic creep response, both of which, especially the former, have been attributed to the grain coarsening phenomenon. Surface damage due to shear banding was also found. Grain coarsening was located near and along the pre-existent shear bands; whereas the already coarsened grains from processing were found to accommodate some plastic strain. Comparison between ECAPed and ARBed copper, specifically the micro-mechanisms involved in accommodating cyclic plastic strain, will be carried out. Similarities between the two types of materials are analyzed to arise from the similar microstructures; whereas the dissimilarities arise from the composite nature, which gives rise to the sequential activation of different micro-mechanisms, in the ARBed microstructure.