Microstructural Model of Magnetic and Deformation Behavior of Single Crystals and Polycrystals of Ferromagnetic Shape Memory Alloy

In this article, a microstructural model of the Heusler alloy with shape memory effect caused by application an external magnetic field is constructed. The dynamics magnetization process are described using Landau–Lifshitz–Gilbert equation. For numerical implementation finite element method, variational equations corresponding to differential formulation problem used. Such approach makes it possible reduce (weaken) requirements for smoothness sought solution. single crystals Ni2MnGa alloy, which has “herringbone”-type martensitic structure (a twinned variant martensite), considered. each twin, domains walls certain thickness formed. motion and interaction these rotation vector in under action differently directed fields studied. These processes also accompanied detwinning process. A condition ferromagnetic proposed, reorientation (detwinning) variants forming twin on material occurrence structural deformation taken into account. First, grain considered at different angles between anisotropy axes field. cases, curves constructed, deformed states identified. such experimental facts as jump result It was shown that occurred magnitude strength applied direction its relative twinning system. Then, based obtained results, arising due were determined various (isotropic texture-oriented) polycrystalline samples, taking account constructed materials.