One-way and two-way shape memory effect in thermomechanically treated TiNi-based alloys

Abstract

One-way and two-way shape memory effects (SME and TWSME) and functional properties of Ti–50.7 at.% Ni alloy after low-temperature thermomechanical treatment (LTMT) and post-deformation annealing are studied. The combined influence of structure realized under isothermal annealing after LTMT and external training parameters on functional properties of this alloy is studied. Variation of strain aging time under isothermal annealing is effective for regulation of critical temperatures and other SME/TWSME parameters. LTMT with subsequent aging at 430 °C for 10 h is favorable for achieving the best combination of TWSME parameters in this alloy. Variation of loading time is effective for regulation of TWSME magnitude under multi-cycle training procedure. The TWSME value achieved is possible after minimum number of training cycles owing to exposure time increasing in a constrained condition.