(color online) (a) Representative temperature variations of NiTi alloy (with an interval of 100 times, 1st, 100th, 200th,…, and 1000th cycle) during tensile cycling tests with a strain rate of 5 × 10⁻³ s⁻¹ at room temperature. (b) Measured maximum temperature change as a function of the cycle number. (c) Representative stress–strain curves of NiTi alloys (with an interval of 100 times, the 1st, 100th, 200th,…, and the 1000th cycle). (d) Critical stress of martensitic transformation as a function of cycle number.