TiNi-based alloys belong to memory titanium alloys, the memory effect is due to the occurrence of thermoelastic or stress-induced martensitic phase transformation in the alloy. Therefore, the key to heat treatment is to ensure that the material but oblique crystal martensite transformation and heat treatment to maintain the martensite morphology.TiNi-based alloy transformation belongs to the body-centered cubic B2 phase to martensite transformation. Due to its composition of different transformation temperature is different. Generally used: 800-850 ℃ quenching, then, 400-500 ℃ × T aging water quenching. Aging temperature and time has a great influence on its memory effect.
The above, is only my personal opinion on doing as nickel-titanium and alloys as memory alloys.
If done as structural materials and corrosion-resistant materials is another matter (generally do not do structural materials, if done as structural materials as far as I know only used in brackets, pipe fittings and fasteners; corrosion-resistant materials commonly used for the TA10, which is very low in nickel content).