Influence of the Annealing Process on Magnetic Performance of Iron based Soft Magnetic Composites

Yan An,1

Shuai Feng1

Guoqing Shao2

Wanli Yuan1

Kai Sun1, E-mail 

Xiaofeng Li1

Runhua Fan1, E-mail

1 College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai 201306, China

2 Shandong Jingchuang Magnetoelectric Industry Technology Research Institute Co., Ltd. Shandong 276000, China 

Abstract

In this work, the reduced iron powders were phosphated to form ferrous phosphate insulating layer on their surface. Then the iron based soft magnetic composites (SMCs) were prepared successfully by powder metallurgy and annealing process. The presence of insulating layer decreased the eddy current loss of iron powders. Furthermore, the effect of the annealing process on magnetic performance was investigated. The appropriate annealing temperature and holding time were carried out in this work. The samples were annealed in a N2 atmosphere from 550 to 650 ℃ and kept for 10 to 30 min.According to the results, the phosphated iron based SMCs that were annealed in a N2 atmosphere at 600 ℃ for holding 15 min of holding time had the satisfying magnetic properties. It has a high resistivity (ρ) of 0.017 3 Ω·cm, a high saturated magnetic flux density (Bs) of 1.408 T, a high maximum permeability (μm) of 263, a low coercivity (Hc) of 197 A/ m and a low core loss (Ps) of 119.70 W/kg at 1 000 Hz (Bm=1 T).

Influence of the Annealing Process on Magnetic Performance of Iron based Soft Magnetic Composites