Twinning Behavior in Wrought Magnesium Alloys and its Connection with Texture, Precipitates and Mechanical Properties

Twinning is an important mechanism for coordinated plastic deformation of magnesium alloys. Pre-setting {10–12} extension twins into magnesium alloy will change the orientation of c-axis of grains and eliminate anisotropy, improving the plasticity and ductility of the alloy. The grains are refined to improve the mechanical properties of the alloy such as yield strength, tensile strength and hardness. Therefore, {10–12} extension twinning in magnesium alloys is becoming more and more popular among magnesium alloy researchers. Many scholars have used electron backscattering diffraction and transmission electron microscope to characterize the internal structure, twin tip and the interaction between twins and precipitate phases of pre-strained magnesium alloys. It was found that {10–12} extended twins can not only weaken the strength of texture, but also change the texture type. The existence of precipitates can not only hinder the growth of twin tip, but also produce stress concentration around it, which promotes the nucleation of new twin variants. Pre-twinning in magnesium alloys can improve the compressive yield stress, but reduce the ultimate compressive strength. In this paper, the mechanism of nucleation and growth of {10–12} extension twins in magnesium alloys, {10–12} extension twins and textures, precipitate, interaction of mechanical properties and the detwinning behavior of {10–12} extension twins are reviewed. Finally, the future development of {10–12} extension twins in wrought magnesium alloys is prospected, and some suggestions are put forward, achieving the aim of providing some reference for further research on the twinning transformation of magnesium alloys.