METHOD FOR OBTAINING WEAR-RESISTANT COATINGS ON ALUMINUM ALLOYS Russian patent published in 2022 - IPC C25D11/06 

FIELD: metal processing.

SUBSTANCE: invention relates to the electrochemical processing of metals, specifically to the application of wear-resistant coatings on aluminum alloys by plasma-electrolytic oxidation, and can be used to create protective coatings with high wear-resistant and anti-friction properties on the wearing surfaces of bearings, sliding bearings, guides and other machine parts made of aluminum alloys used in machine-building, metalworking, machine tool and other industries. The method includes processing the surface of aluminum alloy products by plasma-electrolytic oxidation in borate electrolyte for 90-120 minutes using the anode-cathode mode at pulsed current with pulse duration from 0.0033 to 0.4 s, wherein the anode-cathode mode is combined with galvanostatic, while during processing alternating five-minute oxidation in the anode-cathode mode and five-minute in the galvanostatic or five-minute oxidation in the anode-cathode mode cathode mode and ten-minute in the galvanostatic mode, either ten-minute oxidation in the anode-cathode mode and five-minute in the galvanostatic mode with an effective current density of 15-18 A/dm² in both modes, and an aqueous solution containing 15-25 g/l of potassium tetraborate К₂B₄O₇⋅4Н₂О is used as a borate electrolyte.

EFFECT: increase in the wear-resistant of protective coatings due to the predominant formation of a high-temperature phase of aluminum oxide α-Al₂O₃ in the coating, which has high wear resistance and anti-friction properties.

1 cl, 3 dwg, 3 ex