Thermal Cycling Stability of Ti-19Zr-11Nb-2Ta Shape Memory Alloy

Ti-19 Zr-11 Nb-2 Ta shape memory alloy was subjected to N times（N=0, 5, 10, 20, 50） thermal cycling. The microstructure, mechanical properties and shape memory effects of the alloy samples before and after thermal cycling were investigated by metallographic microscopy, X-ray diffraction analysis and tensile testing. The results show that the biphasic structure of the β-phase and α'' martensite phase remains unchanged after several thermal cycles. After 50 cycles, the tensile strength of the alloy sample is 480 MPa and the elongation is about 5%. The shape memory effect decreases, but the shape memory effect is 0.6% after stretching and unloading at 4% pre-strain, and the shape memory effect is still maintained. Ti-19 Zr-11 Nb-2 Ta shape memory alloy shows good thermal cycle stability.