{10(1)over-bar2}-{10(1)over-bar} Double twinning in magnesium

It is demonstrated that metalworking processes performed at different temperatures can lead to the {10 (1) over bar2}-{10 (1) over bar2} double twinning. This twinning mode has been observed during direct extrusion of the coarse-grained Mg-0.3at.% Al alloy at 433K and analysed in detail on room-temperature rolled magnesium single crystal with the c-axis parallel to transverse direction and the a-axis parallel to rolling direction. The {10 (1) over bar2}-{10 (1) over bar2} double twins originated during initial stage of the formation on coarse-grained and single-crystalline structure.