Influence of Elastic Energy on the Unloading Behaviour of Niti Shape Memory Alloys

Yinong Liu, D. Favier, L. Orgeas

Research output: Contribution to journalArticle


A non-linear unloading path of deformed NiTi shape memory alloys was observed during mechanical testing at various temperatures, giving a strain recovery larger than what expected from elasticity. Whilst the nonlinear unloading path at above the A(S) temperature may be rationalised by a simultaneous reverse transformation from the oriented martensite to austenite, the non-linear strain recovery during unloading at below the A(S) temperature must have a different mechanism, because the thermodynamic driving force for a reverse transformation is negative. This second mechanism is ascribed to a 'self-deorientation' process of the fully oriented martensite and the driving force for this process is attributed to the elastic energy stored in the matrix during the forward deformation process.
Original languageEnglish
Pages (from-to)593-598
JournalJournal de Physique IV
Publication statusPublished - 1995


Cite this