Fe–Si–B–P–Cu Nanocrystalline Alloy Ribbons With High Saturation Magnetic Flux Density Prepared Using Industrial Materials

Magnetic properties and fine structure of Fe-Si-B-P-Cu nanocrystalline alloy ribbons have been investigated. The Fe_84.8(Si,B,P)₁₄Cu_1.2 alloy ribbons using industrial materials are produced by a single-roller melt-spinning method in air. The Fe_84.8(Si,B,P)₁₄Cu_1.2 nanocrystalline alloys exhibit low coercivity H_c of 7-20 A/m in the compositional range of Si=0-2 at% and P=2-8 at% and high saturation magnetic flux density B_s of 1.80 T or more in the compositional range of P=0-4 at%. In particular, Fe_84.8Si₁B₁₀P₃Cu_1.2 nanocrystalline alloy annealed at 698 K exhibits both the high B_s of 1.82 T and the low H_c of 7.2 A/m. The iron loss W at 50 Hz of the Fe_84.8Si₁B₁₀P₃Cu_1.2 nanocrystalline alloy is much smaller than oriented and nonoriented magnetic steel over the maximum induction B_m range up to 1.7 T. In addition, nanocrystalline structure of the Fe_84.8Si₁B₁₀P₃Cu_1.2 alloy exhibits a homogeneous nanocrystalline structure composed of α-Fe grains with 5-20 nm in diameter even using industrial materials. Therefore, the Fe-Si-B-P-Cu nanocrystalline alloy has good soft magnetic properties and a large economical advantage of low material cost by using industrial materials.