R-value and Texture Change of AA 1050 Al Alloy Sheet by Equal Channel Angular Pressing

摘要

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℃ 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.