The role of interaction work in martensite deformation

This study elucidates the evolution of martensite deformation via Interaction Work (IW). The IW is the mechanical work done by external loading, assisting deformation by competing with the energy barrier. This interplay establishes the maximum IW (IWmax) criterion for variant selection of different deformation modes. Considering multiple deformation modes (A, B, …), the deformation mode with min{IWmaxA,IWmaxB,…} is expected to be activated first due to a lower energy barrier when subjected to deformation, which hints the evolution of martensite microstructures with the increasing trajectory of IWmax of various deformation modes. We validated this hypothesis by examining reorientation and deformation twinning in monoclinic martensite (B19’) in NiTi, orthorhombic (α’’), hexagonal martensite (α’) in Ti-based alloys, and γ’ martensite in CuAlNi shape memory alloys, and by comparing the predictions with existing literature.