Active{11(2)1}and{10(1)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)1}and{10(1)2}extension twinning is observed.The activation of{11(2)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)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)2}twin variants,crossing-like TTJs of co-zone{11(2)1}twin variants are observed and their formation mechanisms are discussed.Crossing-like TTJs are also formed by the interaction of{11(2)1}and{10(1)2}twins.The morphology and thickening rate of{11(2)1}and{10(1)2}twins vary markedly due to the difference in twinning shear.The needle-like{11(2)1}twins thicken more slowly than the lenticular{10(1)2}twins.Twin nucleation is observed on the previously formed{11(2)1}twin boundary due to the relatively large strain concentration on such interface,while twin nucleation on{10(1)2}twin boundary is rarely observed.