Unexpectedly formed strong basal texture in a rolled Mg-Zn-Ca-Mn alloy sheet

Abstract

The reheating at high temperature, which contributed to the significant texture weakening in rolled Mg alloys, was used to control the textural features of a Mg-Zn-Ca-Mn alloy sheet. The grain coarsening was apparent when the alloy was reheated at high temperature of 450 °C, facilitating the formation of double twinning and shear bands during rolling. Double twinning and shear bands generally cause the weakening of basal texture after post-annealing; however, the basal texture became strong in the Mg-Zn-Ca-Mn alloy sheet rolled with reheating at 450 °C. The electron backscattered diffraction revealed that the non-uniformly distributed dislocations caused such unexpected textural development. In contrast, when the reheating was performed at 350 °C, the alloy formed uniform deformation-microstructure after rolling, contributing to the apparent texture weakening by the static recrystallization at double twinning during post-annealing.