Improved coating for amorphous alloy with low loss deterioration

Insulation coating for Fe-based amorphous ribbon was studied with emphasis on loss deterioration and interlayer insulation resistivity. An aluminum oxide coating was prepared by the solution anodic deposition process so that the coating thickness could be controlled in a range that did not decrease the packing factor. Even thin aluminum oxide coatings were found to have a high resistivity. Additional coating of one or more inorganic substances on the aluminum oxide results in low loss deterioration both in straight ribbon and toroidal cores. Magnetic domain observation reveals that stress induced by the aluminum oxide coating is relieved by the additional coating, which also enhances the corrosion resistance in a moist atmosphere.<
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