Textured polymer bonded composites with Ni–Mn–Ga magnetic shape memory particles

Textured polymer bonded composites were prepared from polyester resin and Ni–Mn–Ga magnetic shape memory (MSM) particles. Single-crystalline MSM particles ∼60 μm in diameter were obtained by mortar grinding melt-extracted and annealed Ni50.9Mn27.1Ga22.0 (at.%) fibres. The crystal structure of the martensite is tetragonal (5 M). The application of a magnetic field during the curing process of the polyester matrix yields an alignment of the MSM particles. Mechanical compression of the composites leads to easy magnetization behaviour in the compressed direction and harder magnetization behaviour in the perpendicular directions of the composites. This behaviour is attributed to stress-induced twin boundary motion within the MSM particles.