Multiscale microstructural evolution of Fe-Ni-Al-Ti alloy with high magnetization

The Fe-15Ni-3Al-1Ti ribbons are produced by melt-spinning the annealed ingots at 10-40 m/s. The annealed ingots consist of Fe3Ni grains and alpha-Fe-type grain boundary phase, forming a columnar grain microstructure in the vertical direction and getting the maximum saturation magnetic polarization (J(s)) of 1.88 +/- 0.03 T in the cross-section. Before and after the annealing, the ribbons form a cellular structure composed of the Fe3Ni intragranular phase and gamma-(Fe, M), Fe7Ni3, or alpha-(Fe, M) cell boundary phases. Formation of enhanced <100> orientation is the primary mechanism for obtaining a high J(s) of 2.35 +/- 0.07 T in the ribbons. The grain and grain boundary size of the ribbons is reduced by the phase transformation induced by annealing at 600 degrees C. The phase transformation processes of the ribbons before and after annealing are as follows: L ->gamma melt spunFe(3)Ni + gamma(1) -> annealed(sic)Fe3Ni + Fe7Ni3 when melt-spinning at a speed of 10-25 m/s, and L ->gamma -> melt spunFe(3)Ni + Fe7Ni3 annealed(sic)Fe3Ni + alpha -(Fe, Ni) at 40 m/s. Finally, the multiscale microstructure evolution models are used to summarize the phase transformation process of the alloys.