Effect of twin boundary-dislocation and twin boundary-solute atom interaction on detwinning of Mg-2Gd-2Y-0.3Zr alloy

In the present work, the effect of twin boundary-dislocation and twin boundary-solute atom interaction on detwinning of Mg-2Gd-2Y-0.3Zr alloy has been investigated by annealing treatment and change of loading path. The results show that when the samples were precompressed along transverse direction (TD), unloading, and then recompressed along normal direction (ND), the detwinning is the predominant deformation. However, when the samples precompressed along ND were recompressed along TD, the detwinning of {101¯1}-{101¯2} double twin is observed difficultly. The {101¯2} detwinning can also be suppressed completely if the samples precompressed along TD were annealed and then recompressed along ND. This should be resulted from the segregation of Gd and Y solute atoms at twin boundary during annealing. Thus, the yield strength of the presompressed and annealing samples is increased by about 100 MPa compared with the presompressed samples without annealing during recompressing along ND.