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

Abstract

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.