Twins!

[1] Transformation of dislocations during twin variant reorientation in Ni-Mn-Ga martensite structures

Szczerba and Szczerba

The transformation of perfect dislocation configurations during twin variant reorientation in Ni-Mn-Ga martensites was analyzed by means of the correspondence matrix method. It was found that the dislocations may change remarkably the length of the Burgers vectors and hence the self-energy up to several percent of their initial value. It is suggested that this may affect the mechanical condition of operation of the mechanism responsible for twin variant reorientation.

[2] Strengthening and Toughening of Magnesium Alloy by {10-12} Extension Twins

Y Xin et al

The mechanisms of strengthening and toughening of hot-rolled AZ31 magnesium alloy by {10-12} extension twins during strain path changed recompression are studied in current paper. Under favorite orientation, {10-12} extension twinning can occur in {10-12} twins generated by pre-compression along rolling direction. Grain refinement by extension twins dramatically enhances both yield stress and peak stress of reloading along transverse direction without any degradation in elongations, while the effect is closely related with the level of pre-strain.