Thermally induced fracture of single crystal Ni-Mn-Ga ferromagnetic shape memory alloy

摘要

Ni-Mn-Ga is prone to fracture when being thermally cycled. This is very different from other shape memory alloys having thermoelastic phase transformations. During thermal cycling, the cracks propagated by self-propagation, branching, microcracks nucleation, as well as interactions between the cracks. A qualitative description on the crack propagation and subsequent crack network formation is suggested. The mechanism of thermally induced brittleness is discussed.