Influence of physical and microstructural features on soft magnetic properties of injection molded Fe–Si–P alloys at low frequencies

Abstract

In this study, the effects of sintering temperature and the amount of Fe-17 at %P addition were studied for the Fe–Si–P sintered alloys. The Fe–Si–P sintered alloys were fabricated from the four powder admixtures containing Fe-3.5 wt% Si and Fe-17 at% P with powder injection molding. Better magnetic performances were obtained with Fe-17 at% P, which activated the liquid phase sintering and alloying of P and Si in the iron matrix. The higher density, lower oxides, and spheroidal grain were obtained with the increase of sintering temperature. Sintered density was the most important factor to the magnetic induction according to the comparative analysis of alloy composition and microstructural effects. For the permeability, coercivity, and core loss, on the other hand, they were much influenced by the alloy composition and microstructure, especially precipitation of secondary Fe3P phase, solid solution of P and Si in the iron matrix, population of the oxides.