Effect of Hf on the structure of Ni-Ti martensitic alloys

Using X-ray diffraction scanning and resistivity measurements, the structural transformations in Ni-Ti-Hf alloys fabricated by melt spinning have been studied. In alloys consisting 8-20 at% Hf, the monoclinic B19' martensite transforms in a reversible manner to the B2 parent phase at temperatures varying from 100 to 300 degrees C. The effect of Hf on lattice parameters of both the martensitic and parent phases and transformation characteristics is reported.