[SY-F12] Various interfaces related to twinning in hexagonal metals
The {10-12} twin mode is the one most commonly activated in hexagonal metals. A primary part of the lattice transition from the matrix to the twin orientation is shear deformation that converts the [0001] direction of the hexagonal axis in the matrix to a direction almost parallel to the [10-10] direction perpendicular to the <a> axis in the basal plane in the twin. In addition to primary mechanical twinning also several types of double-twins were observed as, for example, {10-11}-{10-12} or {10-12}-{10-12}. Surprisingly, the last one can occur in magnesium with the c/a ratio smaller than √3 but also in zinc with the c/a ratio larger than √3. Various types of symmetrical and asymmetrical interfaces including also basal/basal or prismatic/prismatic boundaries will be discussed and their impact on materials properties will be envisaged.