Ni-Mn-Ga Shape Memory Alloys: Modelling of Magneto-Mechanical Behaviour

Abstract

A predictive model of field-induced strain in Ni-Mn-Ga ferromagnetic shape memory alloys is proposed. In this study, magnetocrystalline anisotropy K _1 is introduced to permit magnetisation rotation in each martensitic platelets. The demagnetisation field induced by the shape of platelet microstructure is investigated. As expected, the strain -induced by magnetic field- in a single crystal is mainly given by the mobility of twin boundaries, by the crystal anisotropy of martensite and by the shape anisotropy of platelet microstructure.