Soft magnetic iron-based powder, method for manufacturing the same, and method for manufacturing a soft magnetic composite

A method for manufacturing a soft magnetic iron-based powder, the method comprising:

• preparing an iron-based core powder;
• preparing a first coating solution containing phosphoric acid;
• forming a first layer coated with an inorganic material containing phosphate on a surface of the iron-based core powder by spraying the first coating solution on the surface of the iron-based core powder;
• preparing a second coating solution in which sodium silicate, mica fine particle, and bismuth (III) oxide fine particle are dispersed;
• forming a second layer in which the sodium silicate, the mica fine particle, and the bismuth (III) oxide fine particle are distributed on the surface of the first layer by spraying the second coating solution on the iron-based core powder on which the first layer is formed;
• preparing a third coating solution in which an organic lubricant and an inorganic lubricant are dispersed;
• and
• forming a third layer in which the organic lubricant and the inorganic lubricant are distributed on the surface of the first layer or the second layer whose surface is exposed by spraying the third coating solution on the iron-based core powder on which the second layer is formed.

A method for manufacturing a soft magnetic composite, the method comprising:

• preparing an iron-based core powder, the iron-based core powder including
• a first layer coated with an inorganic material containing phosphate formed on a surface of the iron-based core powder,
• a second layer in which sodium silicate, mica fine particle, and bismuth (III) oxide fine particle are distributed on a surface of the first layer, and
• a third layer formed on the surface of the first layer or a surface of the second layer whose surface is exposed, in which an organic lubricant and an inorganic lubricant are distributed;
• compression molding the iron-based core powder into a molded article having a predetermined shape using a mold heated to room temperature or 80° C. or less;
• and
• heat-treating the molded article at a temperature in a range of 600 to 700° C.