Effects of Different Treating Time with Electropulsing Current On Properties of Ti-Rich TiNi Alloy

Electropulsing treatment is a faster way to change the temperature compared to traditional heat treatment. In our work, the martensitic transformation and mechanical properties of Ti-rich Ni–55.84 at.%Ti alloy treated by electropulsing current with different treating time were studied. Phase transformation behavior investigated by differential scanning calorimetry show that with increasing time, both the B2-B19’ and B19’-B2 phase transformations shift to higher temperatures due to the decreasing dislocation density. However, the dynamic mechanical analysis shows that the transition temperatures of the treated samples are higher than the as-received samples but decreasing with the increasing treating time. No change was observed in the X-ray diffraction patterns at room temperature. The three point bending test indicates that the superelasticity is improved. The electropulsing treatment is an effective method for heat treating SMA alloys, especially in a selected part of shape memory alloy device.