Berlin 2012 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 41: Joint Session Magnetic Shape Memory Alloys I (jointly with DS, MM)
MA 41.2: Vortrag
Donnerstag, 29. März 2012, 10:30–10:45, H 0106
A multi-phase field model to investigate the elastic and magnetic hysteresis behaviour of twinned Ni2MnGa — •Marcus Jainta1, Christian Mennerich1, Frank Wendler1, and Britta Nestler1,2 — 1IMP, Karlsruhe University of Applied Sciences — 2IAM-ZBS, Karlsruhe Institute of Technology
In the last years, magnetic shape memory alloys became an important matter for material scientists. Due to their fast response time, their large recoverable strain and the good cost efficiency, this material class is well suited to be used as components of actuators or dampers. The microstructure evolution of magnetic shape memory alloys depends on the formation of magnetic domains and on the elastic strains induced by external magnetic fields and mechanical loads. To represent this behaviour, we applied a multi-phase field model of Allen-Cahn type based on a Helmholtz free energy density formulation. It is coupled with a model for linear elasticity and with an implementation of the Landau-Lifshitz-Gilbert equation. The order parameters are related to the different eigenstrains of the twin variants and to the spontaneous magnetization. In this contribution, we describe the model and compare simulation results of our combined micromagnetic phase-field solver with numerical results from the literature. We present simulation results of twinned structures in martensic Ni2MnGa performing elastic and magnetic hysteresis behaviours under external forces. We also show the applicability of the model to polycrystalline systems.