Lattice Parameters of B2 and B19′ Phases in Ti–Ni Alloys Near Transformation Temperatures: Effects of Ni Concentration and Temperature
Gen Hikosaka, Yuri Shinohara, Ryutaro Matsumura, Minoru Nishida, Tomonari Inamura
Abstract
Abstract The Ni concentration and temperature dependence of the lattice parameters of the B2 and B19′ phases in binary Ti–Ni alloys was systematically clarified near the martensitic transformation temperatures, using samples with finely varied Ni concentrations ranging from 50.00 to 51.00 at.%. The differences between the present data and previously reported values were quantitatively explained and reinterpreted in terms of uncertainties in Ni concentration, measurement conditions, thermal history, and extrapolation methods. Furthermore, based on the lattice parameters obtained in this study, the effect of Ni concentration on the suppression of transformation-induced dislocations and the stabilization of thermal cycling behavior was discussed in terms of geometrical incompatibility. From the perspectives of composition increment, temperature steps, consistency in thermal history, and transparency of extrapolation procedure, the present dataset is considered to be among the most accurate, precise, and consistent lattice parameter datasets currently available. This dataset provides a highly reliable basis for evaluating the variation in lattice parameters among literature and serves as a foundation for future investigations into phase transformation behavior in Ti–Ni alloys.