Deep drawability and deformation behavior of AZ31 magnesium alloy sheets at 473K

Abstract

Deep drawing experiments carried out at 473. K revealed that the AZ31 magnesium alloy sheets could be successfully drawn at a limiting drawing ratio (LDR) of 2.3 with a drawn depth of 54. mm. Microstructural and textural evolution in different region of the drawn cup were investigated. In the bottom region which was subject to no deformation, the microstructure and basal texture showed almost no changes. Some fine recrystallization grains appeared in the shoulder region with small thickness strain and the basal texture showed almost no changes. In the wall region with 40% thickness strain, more recrystallization grains were observed, the c-axis of the grains tended to rotate toward the transverse direction (TD) of the rolled sheets and the basal texture evolved into an elongated shape around the normal direction (ND) with the elongated direction perpendicular to the deep drawing direction. A great deal of fine recrystallization grains formed in the edge region with 85% thickness strain and the basal texture dramatically changed to the c-axis//TD texture with basal planes perpendicular to the sheet plane. The formation of this c-axis//TD texture is caused by the activation of non-basal slip systems due to the high deformation temperature. Analyses on basal slip and non-basal slip systems by Schmid factors were carried out to discuss the deformation behavior during deep drawing.