The effect of martensite stabilization in titanium nickelide after various methods of pre-deformation: simulation with a single set of constants

Authors:
Volkov A.E. Belyaev F.S. Volkova N.A. Vukolov E.A. Evard M.E. Rebrov T.V.
Abstract:

Design of shape memory alloy sensors and actuators requires taking into account the martensite stabilization effect, which consists in a shift upward of the reverse martensitic transformation temperatures after preliminary deformation. In this work it is assumed that this effect is due to damage in martensite domain boundaries during pre-straining. This idea is accounted for in a microstructural model by introducing a variable for boundaries damage and formulating evolution equations. The reverse transformation temperature shift is described with one set of constants for three pre-straining modes: deformation of a specimen in the martensitic state, cooling under a constant stress, and deformation in the austenitic state inducing martensite by stress. For Ti50Ni50 and Ti49Ni51 (at. %), the model matches experimental data well for the first two modes and qualitatively for the third.