Effects of Co Element on Microstructure and Magnetic Properties of Fe-6.5wt%Si Magnetic Powder Cores

Fe 100-x Co x -6.5wt%Si (x=0, 1, 3, 5, 7, 10, 15, 35, 50) magnetic powder cores (MPCs) were prepared by gas atomization,insulation, compression molding, and heat treatment. The effects of Co element on microstructure and magnetic properties of the Fe-6.5wt%Si MPCs were investigated. The results showed that the addition of Co element doesn’t change the phase structure of Fe-6.5wt%Si alloy powders. The saturation magnetization of the powders decreased after the first increase with the increase of the Co content, reaching the maximumfor Fe 90 Co 10 -6.5wt%Sipowder sample.The saturation magnetization of the MPCs decreased after the first increase with the increase of the Co content, reaching the maximumfor Fe 93 Co 7 -6.5wt%Si sample.The effective permeability of the MPCsdecreased after the first increase with the increase of the Co content, reaching the maximum for Fe 95 Co 5 -6.5wt%SiMPCs. The core loss of the MPCsincreased after the first decrease with the increase of the Co content, reaching the minimumfor Fe 97 Co 3 -6.5wt%SiMPCs. A small amount of Co element can improve effectively the whole magnetic properties of the Fe-6.5wt%Si MPCs.