On the formation of 11(2)over-bar2 boundary via 10(1)over- bar2-01(1)over-bar2 twin-twin interaction in magnesium

AH Zahiri and L Carneiro and J Ombogo and P Chakraborty and L Cao, COMPUTATIONAL MATERIALS SCIENCE, 201, 110887 (2022).

DOI: 10.1016/j.commatsci.2021.110887

10 (1) over bar2 twinning occurs extensively in Mg to accommodate plastic deformation. With multiple active twin variants, twin-twin interaction occurs and this often forms twin-twin boundaries. In this work, the 11 (2) over bar2 twin-twin boundary is studied using electron backscatter diffraction (EBSD) analysis and atomistic simulations. EBSD data show that many of the twin-twin boundaries align well with 11 (2) over bar2 or 11 (2) over bar6 planes. Further, atomistic simulations reveal dynamically the formation of 11 (2) over bar2 boundary via the interaction of two non-cozone 10 (1) over bar2 twin variants. Moreover, the twinning mode of the 11 (2) over bar2 boundary is found to be an extension twin with second undistorted plane of 11 (2) over bar6. In addition, the 11 (2) over bar2 boundaries contribute significantly to the 60 degrees < 01 (1) over bar0 > peak in the misorientation histogram; they also play an essential role in the unique strong strain hardening under c-axis tension. Our findings are crucial for completing the twinning theories for Mg.

Return to Publications page