Effects of the Al Content on the Evolution of Quadruple Basal Textures in Mg-xAl-1Zn-0.1Mn-0.1Ca-0.2Y Alloy Sheets Processed via Cold Rolling and Annealing

Abstract

The effects of the Al content on the texture evolution of Mg-xAl-1Zn-0.1Ca-0.2Y alloy sheets fabricated via hot rolling, cold rolling, and subsequent annealing were systematically investigated. A lower Al content led to a higher number of free Ca solute atoms that contributed to co-segregation with Zn, delaying the recrystallization of the cold-rolled sheets during annealing and changing the basal pole figure shape of the annealed sheets. A quadruple basal texture, in which the positions of the four basal poles were developed at tilt angles of ±25° to the rolling direction (RD) and ±40° to the transverse direction (TD) from the normal direction, was obtained in the annealed Mg sheets. A smaller amount of Al caused an increase in the intensity of the main peaks along the TD but a decrease in the intensity along the RD. As a result, the texture of the annealed sheets gradually changed from RD-split to diamond and TD-split in the (0002) pole figure, as shown by the relative comparison of pole intensities in both directions. This texture change strongly affects the Schmid factor for the basal slip. For the alloys with an off-basal texture investigated in this study, as the maximum intensity of the basal poles increased, the average Schmid factor of the basal planes also increased, making the basal slip easier.