In the present work, effects of loading scheme and strain reversal on structure evolution are studied by using high pressure torsion (HPT) and twist extrusion (TE) techniques. High purity aluminum (99.99%) was processed at room temperature up to a total average equivalent strain of ～4.8 by TE and HPT with two deformation modes: monotonic and reversal deformation with a step of 12° rotation. It was revealed that microstructural change with straining observed in pure Al was a common consequence of the SPD processing and was not affected significantly by the loading scheme. At the same time, it was found that strain reversal retarded grain refinement in comparison with monotonic deformation.
展开▼
