Crystallization kinetics of (Ni 0.75Fe 0.25) 78- xNb xSi 10B 12 ( x = 0, 5) amorphous alloys

Abstract

Amorphous ribbons of (Ni 0.75Fe 0.25) 78- x Nb x Si 10B 12 ( x = 0, 5) were prepared by a single roller melt-spinning technique in air atmosphere. The crystallization kinetics of the alloys were investigated by means of continuous heating, and the activation energies of the alloys were calculated using Kissinger plot method and Ozawa plot method on the basis of differential thermal analysis data. The crystallization products were analyzed by X-ray diffraction. After the (Ni 0.75Fe 0.25) 78Si 10B 12 amorphous alloy was annealed at the temperatures 715 and 745 K, a single phase of γ-(Fe, Ni) solid solution with grain sizes of about 10.3 and 18.5 nm, respectively, precipitates in the amorphous matrix. The crystallized phases are γ-(Fe, Ni) solid solution, Fe 2Si, Ni 2Si, and Fe 3B after annealing at 765 K. The (Ni 0.75Fe 0.25) 73Nb 5Si 10B 12 amorphous alloy was annealed at 720, 750, and 800 K; and the crystallization phases, γ-(Fe, Ni) solid solution, (Fe, Ni) 23B 6, Ni 31Si 12 and Nb 2NiB 0.16 form simultaneously.