THIN-LAYER CERAMIC COATING AND METHOD OF MANUFACTURING THEREOF Russian patent published in 1997 - IPC

FIELD: coatings. SUBSTANCE: invention relates to applying ferrous and nonferrous metal wear-resistant coatings by the method of microarc oxidation which can be used in mechanical engineering, chemical, and petrochemical industries. One of electrode is aluminium-containing metal composition with 4-10% copper, and the other electrode consists of electrically insoluble metal. Into aqueous electrolyte containing 1-6 g/l alkali and 4-6 g/l liquid glass, powder containing 90% silicon oxide and 10% aluminium oxide with particle size 1-10 mcm is added to concentration 0.5-2.0 g/l. treatment is conducted for 60-180 min in anode-cathode mode with ratio of anode and cathode currents 1.1-1.2. Produced coating consists, at least partially, of coils of filamentary alfa-aluminium oxide crystals contained in small-crystal matrix of gamma-alumina and mullite and is characterized with wear intensity, 10^-10-10^-12; friction coefficient, 0.01-0.035 microhardness, 16-18 GPa; and critical fissuring loading, 2.5-3.0 N. EFFECT: improved physico-mechanical characteristics. 2 cl