Development of novel Fe based nanocrystalline FeBNbPSi alloy powder with high B s of 1.41T by forming stable single amorphous precursor

The possibility of the powderization of precursor with a single amorphous phase was investigated in FeBNbP nanocrystalline alloy particles and FeBNbPSi nanocrystalline alloy powders. Fe90−xBxNb7P3 (x=9, 10), Fe79.5B9.5Nb7P3Si1 and Fe82−x B9Nb6P3Six (x=2, 3) powders were prepared by the gas atomization method using high pressure water for rapid quenching. The as-atomized particle as a precursor exhibiting low Hc of 141 A/m with a single amorphous phase was observed from a cross sectional image and SAED pattern in the Fe80B10Nb7P3 nanocrystalline alloy powder. In addition, the stability of amorphous phase in the FeBNbP nanocrystalline alloy was also significantly improved by the addition of Si. Therefore, the as-atomized Fe79B9Nb6P3Si3 nanocrystalline alloy powder with Si as a precursor powder of nanocrystalline alloy was achieved to exhibit excellent magnetic softness of low Hc of 53 A/m compared to the ordinary Fe73Si11B11Cr3C2 amorphous and Fe73.5Si13.5B9Nb3Cu1 nanocrystalline alloy powders. In addition, the Fe79B9Nb6P3Si3 powder after nanocrystallization at 873K achieved both high Bs of 1.41T and low Hc of 37 A/m compared to ordinary amorphous, and nanocrystalline alloys.