Metal soft magnetic composite material inductor and preparation method thereof

A preparation method for a metal soft magnetic composite material inductor, comprising the following steps of:

• 1) mixing and smelting Fe, Si and Cr according to a following proportion:
• 85-95 wt % of Fe, 4-10 wt % of Si and 1-5 wt % of Cr to obtain an alloy solution;
• 2) making the alloy solution into alloy powder in a water atomization or gas atomization means;
• 3) sifting the alloy powder into a first powder of 15-45 μm, a second powder larger than 45 μm and a third powder smaller than 15 μm according to particle size;
• 4) mixing the first powder, the second powder and the third powder according to a following proportion:
• 60-80 wt % of the first powder, 5-20 wt % of the second powder, 15-35 wt % of the third powder to obtain a mixed powder, and carrying out coating insulation on the mixed powder;
• 5) crushing, granulating and sifting insulated powder sequentially to obtain granulation powder, and pressing the granulation powder into a material cake;
• 6) placing a prefabricated hollow coil assembly in a mold cavity, placing the material cake in a storage bin, liquefying the material cake into the mold cavity in a transfer molding process, and coating the coil assembly;
• 7) curing and demolding, and removing a runner to obtain a semi-finished product;
• and
• 8) solidifying the semi-finished product and preparing an end electrode to obtain a finished inductor,
• wherein in step 4), the mixed powder is added into a resin mixed solution for coating insulation;
• wherein a dosage of the resin mixed solution accounts for 1-5.5 wt % of the mixed powder;
• the resin mixed solution is formed by mixing a solid resin with an organic solvent wherein the solid resin contains a curing agent and a release agent, and the solid resin accounts for 1-10 wt % of the resin mixed solution.