Effects of predeformation on the reverse martensitic transformation of TiNi shape memory alloy

DSC was used to study the effects of predeformation on the reverse martensitic transformation of near-equiatomic TiNi alloy. Both the start temperature A(s) and the finish temperature A(f) of the reverse transformation increased with increasing degree of predeformation, but the algebraic difference between A(s) and A(f) decreased with increasing predeformation until it reached a minimum value, then remained unchanged with further deformation. Transformation heat also increased with increasing predeformation until it reached a maximum value, then decreased with further predeformation. All the phenomena above were considered to be closely related with the release of elastic strain energy during predeformation.