Effect of Si addition on crystallization behavior, thermal ability and magnetic properties in high Fe content Fe-Si-B-P-Cu-C alloy

Dependence on the crystallization behavior, thermal ability and soft magnetic properties of the Fe84.7SixB10.5-xP4Cu0.5C0.3 (x = 0-2.0 at.%) alloys with high Fe content were investigated. The results show that the addition of minor Si significantly weakens the crystallization peaks and increases the amorphous forming ability of the alloys. With the increase of Si content, it improves the second crystallization peak temperature and greatly enlarges the temperature interval between the two crystallization peaks, which broadens the annealing range. When Si content is up to 1.5 at.%, the alloy can effectively inhibit the precipitation of Fe-B compounds during the process of annealing. The addition of Si contributes to the formation of stable nano-structure, leading to a good soft magnetic properties for the amorphous alloy. Through the optimum annealing treatments, the nanocrystalline alloy exhibits the high Ms of 206.5 emu/g (Bs approximate to 1.92 T) and low Hc of 12.5 A/m.