Detwinning of face-centered cubic deformation twins via the correspondence matrix approach

Transformation of dislocations during detwinning of face-centered cubic materials is shown. The analysis is based on the correspondence matrix method and the results are additionally presented on the stereographic projection of a double twin/matrix lattice. The results show the existence of three different detwinning modes. One associated with reverse twinning mode and two others associated with pseudo-reverse twinning modes. It was found that only the reverse twinning mode is eventually able to cancel physical consequences of face-centered cubic deformation twinning (change of crystal shape and crystal orientation) including the effect of dislocation hardening (glissile to sessile dislocation transition). The other two detwinning modes lead to further dislocation hardening of a de-twinned crystal by instead producing very sessile dislocation configurations. The differences in physical consequences between the different detwinning modes will be effectively enhanced during further deformation processes involving higher order detwinning, except for the effect of crystal orientation. The obtained results and the elaborated analytical methods may serve as a proper geometrical basis for further experimental procedures involving transmission electron microscopy techniques to study de-twinned structures of dislocated face-centered cubic materials.

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