FeBNbP nanocrystalline alloy powder with high amorphous forming ability and high Bs for magnetic core

Abstract

The influence of P content on amorphous forming ability and the magnetic characteristics were investigated in the FeBNbP nanocrystalline alloys using metallic ribbons. The Fe84-xB9Nb7Px(x=0-3) and Fe80B10Nb7P3 nanocrystalline alloy metallic ribbons prepared by a single-roller melt-spinning method. The Fe84-xB9Nb7Px (x=0-3) and Fe80B10Nb7P3 nanocrystalline alloys annealed at 873-923 K consist of stable α-Fe grain formed in a residual amorphous phase, and the nanocrystal α-Fe grain showed the average diameter from 6.3 to 7.7 nm. The critical thickness of ribbons indicating amorphous forming ability was increased from 20 μm to 68.7 μm with Fe81B9Nb7P3 by increasing P content. The Fe81B9Nb7P3 alloy also exhibited a high saturation magnetic flux density, Bs, of 1.51 T. In addition, Fe81B9Nb7P3 alloy indicated a good magnetic softness with a low coercivity, Hc, of 4.8 A/m. The Fe80B10Nb7P3 alloy increasing B content succeeded to obtain the powder with precursor of a stable amorphous phase by rapid quenching gas atomization method.