Article ID: MT-M2023202
Accumulation behavior of transformation-induced dislocation upon thermal cycling of Ti–30Ni–20Cu which satisfies the triplet condition (TC) was compared to that of Ti–39Ni–11Pd which is known as low hysteresis shape memory alloy designed by the condition that the middle eigenvalue of lattice deformation is 1 (CC1). The dislocation density was determined by the Williamson-Hall method. Although the 0.2% proof stress of the Ti–30Ni–20Cu alloy was about half that of the Ti–39Ni–11Pd alloy, the dislocation accumulation behavior was almost the same in both alloys. The formation of transformation-induced dislocation is effectively suppressed by satisfying TC, more than equivalently to satisfying CC1 only. TC is suggested to be a new guideline to design durable shape memory alloy.
