Local transformation strain measurements in precipitated NiTi single crystals

The objective of this work was to determine the effect of composition on the local transformation strain in NiTi single crystals. Using in situ digital image correlation to obtain full-field strain measurements, we revealed that increasing Ni concentration and precipitate volume fraction results in smaller local transformation strains. Comparison of the local strain measurements to theoretical calculations indicated that detwinning strains are limited in Ni-rich compositions. It was also found that the Ni-rich compositions displayed a more homogeneous transformation.