Surface form memory by indentation and planarization of NiTi: displacements and mechanical energy density during constrained recovery

Indentation-induced two-way shape memory leads to pronounced temperature dependence of the depth of spherical indents made in martensitic NiTi shape-memory alloys. They are shallower when austenitic, and depth varies during both M → A and A → M transformations. If the impression is planarized, by metallographic grinding at T 107 J/m3, fully ~10% of the M → A enthalpy.