METHOD OF PREPARING ELECTROINSULATING COATING ON AMORPHOUS AND NANOCRYSTALLINE ALLOY TAPES, COMPOSITION FOR APPLYING COATING, AND METHOD OF PREPARATION THEREOF

摘要

FIELD: metallurgy and electrical engineering. SUBSTANCE: method of preparing coating includes applying composition onto a surface to be treated, thermal treatment in air in gradient condition from 25 to 250-320 C with velocity of tape movement 0.3-0.4 m/min and tempering at temperature of crystallization of tape material or at temperature by 80-120 C lower than that temperature. Tempering can be performed upon exposure to longitudinal stationary magnetic field with intensity more than 50 H from tape material. Composition contains, wt. -%: phosphorus pentoxide, 24.5-28.0; zinc oxide, 11-12; lithium carbonate, 9.5-10; water, the balance. Composition is prepared by mixing initial components in the following order. Zinc oxide is first added to phosphoric acid. After zinc oxide is completely dissolved, lithium carbonate is portion-wise entered under rigorous stirring. When carbon dioxide release stops, mixture is allowed to stand for 8-10 h and then diluted with water to density 1.25-2.33 g/cu.cm. EFFECT: increased degree of reduction of squareness coefficient and specific magnetic loss at elevated back magnetization frequencies, and improved adhesion characteristics. 3 cl, 4 tbl