Special Features of Thermal and Stress Hysteresis of B2–R–B19' Martensitic Transformations in Aged [001]-Oriented Ti–50.6 at.% Ni Single Crystals

Stress-induced and thermal-induced martensitic transformations (MTs) in compression were investigated in [001]-oriented Ti–50.6 at.% Ni single crystals aged at 573 K for 1.5 h, containing Ti3Ni4 particles. No staging associated with stress-induced B2-R MT is detected. The change in the sequence of stress-induced MT from R–B19 ' to B2–B19 ' is accompanied by a change in the slope of the stress-temperature dependence from 3 MPa/K in the first stage to 7.5 MPa/K in the second stage. During stress-induced R–B19 ' MT, thermal and stress hysteresis significantly decrease with an increase in the applied stress and test temperature. At the stressinduced B2–B19 ' MT, hysteresis is independent of the stress and temperature.