Fe-P based nanocrystalline alloys with good soft-magnetic properties via Nb microalloying

The demand for nanocrystalline alloys with excellent soft magnetic properties as well as satisfactory processibility leads to the development of Fe-P based nanocrystalline alloys. In this work, Fe-P based Fe_85.5-xP₁₁C₂B₁Cu_0.5Nb_x (x=0, 0.1, 0.3, 0.5, 1.0 and 1.5) nanocrystalline alloys with high saturation magnetization (B_s), low coercivity (H_c), wide annealing temperature range, large annealing duration interval and good bending ductility are successfully prepared through Nb microalloying. This kind of nanocrystalline alloy exhibits high B_s and low H_c in the range of 1.41-1.81 T and 2.41-12.03 A/m. Especially, Fe_85.4P₁₁C₂B₁Cu_0.5Nb_0.1 alloy shows optimal soft magnetic properties, with high B_s of 1.81 T and low H_c of 5.4 A/m. All alloys maintain low H_c after ten-minute heat treatment at various temperatures of up to T_x2, proving high stability during heat treatment, as evidenced by microstructure characterization, domain observation and thermal analysis. The newly developed Fe_85.4P₁₁C₂B₁Cu_0.5Nb_0.1 alloy, with high B_s, low H_c, good processibility and low-cost advantage, provides a promising candidate for high-performance soft magnetic applications.