Martensitic twins reorientation and stress-strain behavior of ferromagnetic shape memory alloys Ni-Mn-Ga single crystals

Ferromagnetic shape memory alloys Ni53Mn23.5Ga23.5, Ni54Mn23Ga23 and Ni50Mn27Ga23 single crystals were prepared by zone-melting unidirectional solidification. The orientations of the cut single crystals were determined by X-ray diffraction method. The Ni-Mn-Ga crystal growth direction is along [100] with the deviation less than 5degrees. The martensitic twins reorientation process was detected by the stress-strain curves. The compression experiments along different directions were performed, respectively. The results show that the compression improves the texture of favorable martensitic variants and turns them into a single martensitic variant by martensite reorientation.