Quasi in situ observation of twinning evolution during strain path change in magnesium alloy

Tensile twinning plays an important role in the magnesium alloys. In this work, the microstructures and the twinning behaviors in a rolled AZ31 magnesium alloy have been investigated during strain path change using quasi in situ electron-backscattered diffraction method. The results show that detwinning can only occur in grains with certain orientations and is not prevalent in this case. Under compressive strain along the rolling direction, single twin variant with the highest Schmid factor value can be activated, while under re-compressive strain along the transverse direction, several more types of twin variants can be activated. The activation of 10 1 ¯ 2 - 10 1 ¯ 2 double twin has also been observed during strain path change. The double twin activation confirms that one twin variant cannot transmit through another twin variant, but forms an “apparent crossing” twin structure. Graphical abstract