Twinning, grain orientation and texture variation of AZ31 Mg alloy during compression by EBSD tracing

In order to investigate the micro-mechanism of warm forming of Mg alloys, three specimens cut from a rolled AZ31 sheet were chosen to be compressed along the Rolling Direction (RD) at 100 °C, 170 °C and 230 °C, separately. During compression, an in situ measurement of grain orientation in the plane of RD × TD (Transverse Direction) was carried out with EBSD method. Experimental and analytical results show that temperature has remarkable impact on activation of twinning and variation of texture. As the temperature was raised from 100 °C to 230 °C, the number of grains with twins activated decreased substantially during deformation, and rolling texture varied from quick vanishing at 100 °C to always existing at 230 °C. Tracing for orientation of individual grains during deformation shows that there are obvious different orientation changes between grains with twins activated and those without twins activated. Twinning plays a significant effect on texture variation during compression. The extension twin variant really activated during deformation is the one with maximal Schmid factor.

► An in situ tracing of grain orientations during compression was carried out.
► Changes of basal texture of rolled sheets during compression at different temperatures were compared.
► The extension twin variants were decided by some ways.
► The relationship of extension twin variant activation and Schmid factor was obtained.