Glass formation, crystallization, and magnetic properties of the FeNiCrNbB amorphous ribbons

Abstract

In present work, the glass forming ability (GFA), crystallization, and magnetic properties of the (Fe1-x-y Ni x Cr y )65Nb7B28 (x = 0.05, y = 0.05; x = 0.05, y = 0.1; x = 0.1, y = 0.05) alloys under both as-quenched and as-annealed state were studied. The results show that the introducing Ni and Cr significantly improves the GFA and thermal stability, while it decreases the soft magnetic properties for the as-quenched (Fe1-x-y Ni x Cr y )65Nb7B28 alloys. The Fe68Nb4Cr8Nb5B15 alloys were regarded as good glass-former with Δ - T x = 59 K and T x1 = 846 K. Isothermally annealing treatment were carried out on the (Fe1-xyNixCry) 80Nb5B15 alloys. The crystallization products are α --Fe and Cr3B4 phases for alloys annealed at low temperature, while mixed structure of α - Fe, Fe2B, Fe3B, Ni3B4 and Cr3B4 phases are identified for alloys annealed at high temperature. Besides, increasing annealing temperature deteriorates their soft magnetic properties. Annealing above T p1 decreases the saturation magnetization. However, further increase of annealing temperature (> T p2) makes the soft magnetic properties almost disappear.