Effect of heat treatment on shape memory effect and superelasticity in Ti–Mo–Sn alloys

Ti–Mo–Sn alloys have been developed as a substitute for Ti–Ni alloys in the biomedical field. The effect of heat treatment on shape memory and superelastic properties in Ti–Mo–Sn alloys has been investigated. The shape memory effect is improved by aging at 873 K for 180–420 s in the Ti–5 mol% Mo–4 mol% Sn alloy and superelasticity is improved by aging at 873 K for 180–300 s in the Ti–5 mol% Mo–5 mol% Sn alloy. A large superelasticity with the recovery strain of 3.5% is obtained in the Ti–5 mol% Mo–5 mol% Sn alloy aged at 873 K for 300 s at room temperature. It has been understood that the improvement of superelasticity is due to an increment in the recovery strain with the reverse transformation of stress induced martensite. The superelasticity in Ti–5 mol% Mo–5 mol% Sn alloy aged at 873 K for 300 s is superior to that in the solution-treated alloy over wide temperature range.