On the deformation of the twinned domain in NiTi shape memory alloys

Owing to its importance in understanding the mechanical and thermomechanical behaviours of shape memory alloys (SMAs), the deformation mechanism of martensitic twins has been of continuous research interest. Several deformation steps have been distinguished in accordance with the stress -strain curves, and some explanations have been proposed on the basis of microstructural studies. However. various experimental observations have suggested that It complete understanding of the macroscopic deformation behaviour of the twinned martensitic NiTi SMAs from a microscopic scale is yet to be established. The present research aims at providing a further insight into the microstructural variations under tension within each deformation stages and trying to correlate these changes to the observed mechanical behaviour. As a result, the understanding of the deformation behaviour of NiTi martensite under tension is refined.