Phase field modeling to transformation induced plasticity in super-elastic NiTi shape memory alloy single crystal

摘要

A crystal plasticity based phase field model was established to investigate the occurrence of transformation induced plasticity (TRIP) and its effect on the cyclic transformation of super-elastic NiTi shape memory alloy (SMA) single crystal. The simulation shows that the martensite transformation and its reverse result in the occurrence of plastic deformation in the NiTi SMA single crystal and the mode of phase transition changes from a localized mode into a homogeneous one with the cycles. When the single crystal exhibits a localized martensite transformation, the TRIP occurs regularly at the interfaces between the martensite-dominated and austenite-dominated domains and then the strips of equivalent plastic strain are formed; meanwhile the TRIP hinders the martensite transformation in the austenite-dominated domains but promotes that in the martensite-dominated ones. When the transformation becomes homogeneous, the TRIP occurs in a scattered mode and with a high value, and promotes the martensite transformation in the whole single crystal. In addition, the interaction between the residual martensite phase and TRIP is investigated, and the results demonstrate that they promote each other to some extent.