Nanocrystallization of Ni-Fe-Nb-Si-B amorphous alloys

Four amorphous alloys, NixFe75 - xNb3Si9B13 with x = 35, 45, 55, 58, were p repared by a melt-quenching technique. The thermal instabilities of the amo rphous alloys were studied by using the differential scanning calorimetry ( DSC) and the crystallization temperatures have been determined. The crystal lization behaviors and the structural characteristics of the alloys were in vestigated by means of X-ray diffraction experiments. The amorphous alloys were annealed for 30 min at different temperatures: 450, 480, 500, 550, 580 and 600 degrees C, respectively. The crystallization phases were identifie d and the grain sizes were estimated. The concentration of Ni element in a crystallization phase, gamma-(Fe,Ni) solid solution, varied with the alloys . The Ni-Fe-Nb-Si-B alloy with an equal atom percentage of Ni and Fe elemen ts might be a critical composition as the crystallization phases were chang ed over this composition. (C) 2000 Elsevier Science S.A. All rights reserve d.