Twinning behavior of Mg–4Zn–1Gd alloy sheet during longitudinal tensile deformation

Tension twinning is the dominant twinning mode during longitudinal tensile deformation of Mg–4Zn–1Gd alloy sheet, although the stress state is unfavorable for such formation due to the alloy’s characteristic texture showing a broadening of angular distribution of basal poles along the transverse direction (TD). Tension twinning is a result of the operation of compressive stress along the TD, due to constraint by neighboring grains. The formation of other twinning modes, such as compression twinning and double twinning, occurs after necking.