Large-area bulk ultrafine grained （UFG） pure Cu was successfully prepared by multiple-pass overlapping friction stir processing （FSP） under additional rapid cooling. Overlapping FSP did not exert a significant eff...Large-area bulk ultrafine grained （UFG） pure Cu was successfully prepared by multiple-pass overlapping friction stir processing （FSP） under additional rapid cooling. Overlapping FSP did not exert a significant effect on the microstructure and mechanical properties of the FSP UFG Cu. Similar average grain size was achieved in the transitional zone （TZ） of the multiple-pass FSP sample compared to that in the nugget zone of the single-pass FSP sample, and the TZ exhibited a strong {111}（112） type A fiber shear texture, Very weak softening occurred in the TZ of the multiple-pass FSP UFG Cu, resulting in a relatively uniform hardness distribution throughout the whole processed zone. A high yield strength of - 310 MPa and a uniform elongation of - 13% were achieved in the bulk FSP UFG Cu. This study provides an effective strategy to prepare large-area bulk IUFG materials.展开更多
文摘Large-area bulk ultrafine grained （UFG） pure Cu was successfully prepared by multiple-pass overlapping friction stir processing （FSP） under additional rapid cooling. Overlapping FSP did not exert a significant effect on the microstructure and mechanical properties of the FSP UFG Cu. Similar average grain size was achieved in the transitional zone （TZ） of the multiple-pass FSP sample compared to that in the nugget zone of the single-pass FSP sample, and the TZ exhibited a strong {111}（112） type A fiber shear texture, Very weak softening occurred in the TZ of the multiple-pass FSP UFG Cu, resulting in a relatively uniform hardness distribution throughout the whole processed zone. A high yield strength of - 310 MPa and a uniform elongation of - 13% were achieved in the bulk FSP UFG Cu. This study provides an effective strategy to prepare large-area bulk IUFG materials.
