Crystallization kinetics of (Ni_(0.75)Fe_(0.25))_(78-x)Nb_xSi_(10)B_(12) (x = 0,5) amorphous alloys

摘要

Amorphous ribbons of (Ni_(0.75)Fe_(0.25))_(78-x)Nb_xSi_(10)B_(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_(0.75)Fe_(0.25))_(78)Si_(10)B_(12) amorphous alloy was annealed at the temperatures 715 and 745 K, a single phase of gamma -(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 y-(Fe, Ni) solid solution, Fe_2Si, Ni_2Si, and Fe_3B after annealing at 765 K. The (Ni_(0.75)Fe_(0.25))_(73)Nb_5Si_(10) B_(12) amorphous alloy was annealed at 720, 750, and 800 K; and the crystallization phases, gamma -(Fe, Ni) solid solution, (Fe, Ni)_(23)B_6, Ni_(31)Si_(12) and Nb_2NiB_(0.16) form simultaneously.