Reducing the tension–compression yield asymmetry in a hot-rolled Mg–3Al–1Zn alloy via multidirectional pre-compression

The effect of multidirectional pre-compression on the tension–compression asymmetry in a hot-rolled Mg–3Al–1Zn alloy is investigated in the present paper, revealing that the tension–compression asymmetry is greatly decreased via multidirectional pre-compression. The analysis of deformation behaviors through in situ EBSD observation demonstrates that the { 10 1 ¯ 2 } – { 10 1 ¯ 2 } double twins could be generated in the previously formed { 10 1 ¯ 2 } twins and the existing { 10 1 ¯ 2 } – { 10 1 ¯ 2 } double twins could be de-twinned to the { 10 1 ¯ 2 } twins under favorable orientations. De-twinning could happen through the movement of the boundaries and the nucleation of new lamellas. In addition, the { 10 1 ¯ 2 } – { 10 1 ¯ 2 } – { 10 1 ¯ 2 } twins are difficult to occur in narrow { 10 1 ¯ 2 } – { 10 1 ¯ 2 } twins under low stresses, causing de-twinning to also happen in the double twins even though their orientation facilitates the activation of { 10 1 ¯ 2 } – { 10 1 ¯ 2 } – { 10 1 ¯ 2 } twinning.