Elastic shape memory effect in In-Pb alloys in the temperature range 0.48–180 K

Pseudoelasticity caused by pseudotwinning in short-range ordered In-Pb alloys (6, 8 and 11.6 at. % Pb) is studied in the temperature range 0.48–180 K. The mechanical hysteresis parameters, namely, the thermodynamic stress τ _T which provides the reversibility of plastic deformation and the frictional stress τ _f which characterizes the resistance offered by crystal lattice and its defects to twin boundaries motion are estimated. It is found that athermal processes determine the reversible deformation: the mechanical parameters τ _T and τ _f do not depend on temperature and strain rate. The stress τ _T increases and the stress τ _f decreases with increasing Pb content. One of the main conditions of the exhibition of superelasticity is the fulfillment of the inequality τ _T >τ _f .