Narrow hysteresis behavior of TiNi shape memory alloy constrained by NbTi matrix during incomplete transformation

Constrained incomplete transformation hysteresis of TiNi shape memory alloy embedded in NbTi matrix was studied by thermal dilatation. Results showed that hysteresis width (temperature difference between one incomplete transformation arrest temperature and the subsequent reverted transformation starting temperature) was very narrow, and it reduced to almost zero in the thermal cycle where the testing temperature range was not beyond its previous one. Furthermore, transformations which showed such narrow hysteresis width could be observed within a very wide temperature range.