Soft Magnetic Metal Powder Coating for Resistivity and Low Coercivity

The insulating coating is divided into two distinct layers: a first insulating layer containing Si and O, and a second insulating layer containing P. This segmentation allows each layer to contribute differently to the overall performance, with the first layer providing base insulation and the second layer enhancing powder resistivity through phosphorus-containing compounds that increase inter-particle resistance.

The coating structure uses composite materials with different chemical compositions and properties. The first insulating layer (Si-O based) and second insulating layer (P-containing) form a composite coating system that combines the advantages of both materials, achieving both good insulating performance and high powder resistivity that neither layer could achieve alone.

Each insulating layer is designed with specific local qualities: the first insulating layer has optimized Si and O content for base insulation, while the second insulating layer has optimized P content for resistivity enhancement. The thickness and composition of each layer are locally optimized to achieve the desired balance between insulation and magnetic properties without excessive total coating thickness.

The invention optimizes specific parameters including the thickness of each insulating layer, the concentration ratios of Si, O, and P elements, and the structural characteristics of each layer. By precisely controlling these parameters, the coating provides sufficient insulation and resistivity while maintaining the soft magnetic properties of the underlying metal particles.