This paper focuses on the optimization of shape memory effect (SME) and two-way SME (TWSME) training parameters bringing maximum two-way recovery strain. the joint effect of isothermal annealing at 430°C after Low-Temperature Thermomechanical Treatment (LTMT) and external training parameters on functional properties of Ti-50.7%Ni alloy is studied. The homogenizing annealing at 700°C, 20 min is chosen as a reference heat treatment (RHT). Under experiment procedure, the bending loading mode, strain state, loading value and loading time were varied. Increasing of strain aging time from 10min to 10hr affects characteristic temperatures А_s and А_f after aging and RHT, however, in the case of LTMT the А_s - А_f temperature range is significantly wider than after RHT. The TEM and X-ray studies testify that it is caused by two factors: heterogeneity of nano-size subgrain structure and nano-phase Ti₃Ni₄ precipitates.

The evolution of SME and two-way TWSME parameters is studied as well. The recovery strain ε_r and TWSME amplitude ε_TW  increase with aging time. variation of loading time is effective for ε_TW regulation under multi-cycle training procedure. The achievement of required TWSME value is possible after minimum number of training cycles owing to exposure time increasing in a constrained condition. The loading mode and constraining strain ε_t strongly affect all studied SME and TWSME parameters.

Variation of training parameters enables additional precise regulation of final functional properties. The obtained results can be used for development elements functioning in conditions of TWSME realization.

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