Active {1121} and {10 1 over line 2} extension twinning in a WE43 Mg alloy

Deformation twinning in a WE43 alloy subjected to uniaxial compression at room temperature is in-vestigated. Active {11 2 over bar 1} and {10 1 over bar 2} extension twinning is observed. The activation of {11 2 over bar 1} twinning in a certain grain is influenced not only by its own Schmid factor, but also by that of the basal slip. Twin-twin interactions of the co-zone {11 2 over bar 1} twin variants are commonly observed and systematically studied, including the crystallographic characteristics of the four typically observed twin-twin junctions (TTJs) and the associated twin-twin boundaries. Unlike the quilted-looking TTJs formed by the interaction of co-zone {10 1 over bar 2} twin variants, crossing-like TTJs of co-zone {11 2 over bar 1} twin variants are observed and their formation mechanisms are discussed. Crossing-like TTJs are also formed by the interaction of {11 2 over bar 1} and {10 1 over bar 2} twins. The morphology and thickening rate of {11 2 over bar 1} and {10 1 over bar 2} twins vary markedly due to the difference in twinning shear. The needle-like {11 2 over bar 1} twins thicken more slowly than the lenticular {10 1 over bar 2} twins. Twin nucleation is observed on the previously formed {11 2 over bar 1} twin boundary due to the relatively large strain concentration on such interface, while twin nucleation on {10 1 over bar 2} twin boundary is rarely observed. (c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.