Development of novel Fe based nanocrystalline FeBNbPSi alloy powder with high Bs 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. Fe_90−xB_xNb₇P₃ (x=9, 10), Fe_79.5B_9.5Nb₇P₃Si₁ and Fe_82−x B₉Nb₆P₃Si_x (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 H_c 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 H_c of 53 A/m compared to the ordinary Fe₇₃Si₁₁B₁₁Cr₃C₂ amorphous and Fe_73.5Si_13.5B₉Nb₃Cu₁ nanocrystalline alloy powders. In addition, the Fe₇₉B₉Nb₆P₃Si₃ powder after nanocrystallization at 873K achieved both high B_s of 1.41T and low H_c of 37 A/m compared to ordinary amorphous, and nanocrystalline alloys. [ABSTRACT FROM AUTHOR]