© 2015 IOP Publishing Ltd. The grain size effect on B19′ martensitic transformation temperatures of a nanocrystalline Ti-50.2 at%Ni alloy was investigated by differential scanning calorimetry (DSC) analysis and (TEM) observation. It was found that the R → B19′ transformation temperature decreases with decreasing grain size in the range of 50-150 nm, whilst the reverse B19′ → R transformation temperature remains independent of grain size, leading to an increase of the hysteresis with decreasing grain size. The observed effects of grain size on the characteristics of the R 虠 B19′ transformation are attributed to variations of both the elastic and the irreversible energies of the martensitic transformation in the nanograin regime.
Shi, X. B., Ma, Z. Y., Zhang, J., Ding, H. L., Guo, F. M., Liu, Y., & Cui, L. S. (2015). Grain size effect on the martensitic transformation temperatures of nanocrystalline NiTi alloy. Smart Materials and Structures, 24(7), 1-5. https://doi.org/10.1088/0964-1726/24/7/072001