Evolution of microstructure and crystallographic texture of Ni-Mn-Ga melt-spun ribbons exhibiting 1.15% magnetic field-induced strain

The microstructure and texture evolution of 10M Ni-Mn-Ga melt-spun ribbons were thoroughly evaluated by high-energy synchrotron radiation electron backscatter diffraction. as-spun subjected to annealing treatment in order tailor microstructure, atomic degree, crystallographic texture. optimum at 1173 K for 72 h produced a homogenous <100> fiber induced grain growth the size that spans entire ribbon thickness. This turn reduced microstructural constraints twin variant reorientation direction perpendicular surface. On other hand, radial ensured in-plane stress/strain compatibility giving rise strain accommodation during reorientation. Particular attention was also given evaluation order, which largest extent controls characteristic transformation temperatures. It lowered twinning stress level sufficiently low martensitic under magnetic field. As result, 1.15% field-induced without aid mechanical training self-accommodated state achieved.