Papers by Keyword: Severe Shear Deformation

Abstract: A differential speed rolling (DSR) processing with a roll speed ratio of 1.167 was carried out on an AZ31 alloy for investigating the effects of DSR on microstructure, texture and mechanical properties. The DSR processed sheet showed unidirectional shear bands with a small grain size of 5.5 μm inclining to the rolling direction, and the basal plane tended to incline at about 15º from the rolling plane toward the rolling direction. Compared with the normal rolled sheet, the DSR processed sheets showed a lower proof stress and a larger elongation with an increase from 21% to 26% in the rolling direction. The proof stress increased and the elongation decreased with the angle between the tensile direction and the rolling direction.

Abstract: Ultra-fine grained and high hardened Al sheet was obtained by Equal Channel Angular Pressing (ECAP). During this process the microstructure, the hardness and the texture of AA 1050 Al alloy sheet are changed by a severe shear deformation. The plastic strain ratio after the ECAP and subsequent heat-treatment condition was investigated in this study. It was found that the average r-value of the equal channel angular pressed and subsequent heat-treated specimen was 1.7 times higher than that of the initial Al sheet. This could be attributed to the various texture formations through the ECAP and subsequent heat-treatment of AA 1050 Aluminum alloy sheets.

Abstract: By severe plastic deformation of metals, an ultra fine grain size can be obtained. In the present study an AA 1050 Aluminium alloy has been severe deformed by Equal channel angular pressing (ECAP). A study on the microstructure and the texture of the samples after ECAP and subsequent heat treatment has been carried out. The specimens after ECAP showed a very fine grain size, a decrease of <100> // ND, and an increase of <111> // ND textures. The {111}<112>, {123}<634>, {110}<001>, {112}<111>, {110}<111>, and {013}<231> texture components were increased in the specimens after the ECAP and subsequent heat-treatment at 400° C for 1 hour. One of the most important properties in sheet metals is formability. The r-value or plastic strain ratio has been used as a parameter that expresses the formability of sheet metals. The change of the plastic strain ratios after the ECAP and subsequent heat-treatment conditions has been investigated and it was found that they were two times higher than those of the initial Al sheets. This could be attributed to the formation above texture components through the ECAP and subsequent heat-treatment.

Abstract: . Equal channel angular pressing (ECAP) is useful method to obtain the ultra-fine grained and the high hardened metal. The microstructure, the hardness, and the texture of the 1050 Al sheets by ECAP are changed by a severe shear deformation. The change of the microstructure, the hardness, and the texture were investigated on the 1050 Al sheets that were prepared by ECAP and annealing.