Bulk hard magnetic alloys in Nd-Fe-B system prepared by casting and melt spinning

Cylindrical cast rods and melt-spun ribbons of Nd₆₀Fe₃₀B₁₀ and two Nd₆₇Fe₂₆B₇ and Nd₁₀Fe₇₃B₁₇ eutectic alloys were prepared by copper mold casting and melt spinning. Coercivity of the as-cast Nd₆₀Fe₃₀B₁₀ rod was 434 kA/m. Coercivity of the cast rod was increased to 1285.6 kA/m after annealing due to the formation of Nd₂Fe₁₄B phase. The as-cast eutectic Nd₆₇Fe₂₆B₇ rod, which is partially amorphous, exhibited coercivity value identical to that of the alloy Nd₆₀Fe₃₀B₁₀ (∼430 kA/m). On the other hand, eutectic Nd₁₀Fe₇₃B₁₇ shows better glass forming ability, but lower coercivity (∼100 kA/m).