Evaluation of the reliability of twin variant analysis in Mg alloys by in situ EBSD technique

Abstract Electron backscatter diffraction (EBSD) is an orientation mapping technique, which has been widely used to study texture evolution and twinning behavior. This work aims to study the variant of { 10 1 ¯ 2 } twins during tensile deformation of AZ31 Mg alloys. An in-situ tensile stage was used, and coupled with EBSD technique, the variants of twins can be analyzed without releasing the tensile stress. Based on the EBSD maps, the first and second smallest misorientation angles ( M 1 and M 2 ) between each active twin and respective potential variants were calculated, and the distribution of M 1 values with tensile strain was obtained. The results indicated that { 10 1 ¯ 2 } twins were deviated from their ideal orientations with strain increased. The criteria of M 1 M 2 − M 1 >2° were suggested to be applied to select the data points for reliable variant identification. Moreover, it confirmed that the deviation of twin relationship was ascribed to the profuse basal glide in matrices and/or twins.