Deformation twinning of the B2 austenitic phase in NiTi was considered. The observations could not alone explain the complex shears and shuffles that produced the twin. It was proposed that twinning could occur via (211)[111] shear, and the proposed shuffle was parallel to the twinning shear. A twin energy barrier was established which was lower when compared with previously proposed twinning modes, and had a magnitude of 79mJ/m2. Hydrostatic pressure was found to alter this energy barrier and the coupling of shear and shuffle mechanisms.

Coupled Shear and Shuffle Modes during Twin Growth in B2-NiTi. T.Ezaz, H.Sehitoglu: Applied Physics Letters, 2011, 98[24], 241906