FIELD: technological processes.
SUBSTANCE: invention relates to electrochemical coating of valve metals (aluminum, titanium, magnesium) and their alloys by microarc oxidation (MAO) for a wide range of application not only on new products, but also products after operation, for example, for recovery of coatings after wear. Method comprises immersing an article in a bath with an aqueous solution of electrolyte and MAO in a pulse anode-cathode mode, wherein MAO is carried out at a rate of coating growth on the edges and corners higher than in the center of the article, using a device, where the charge unit has a controlled pulse up-converting quasi-resonance converter with current and voltage operation mode, anode voltage is set from 350 to 500 V and gradually increasing it from 500 to 600 V, and cathode voltage is kept constant from 0 to 100 V, wherein duration of anode pulses is set from 50 to 300 mcs, cathode pulses - from 50 to 100 mcs, pulse repetition frequency from 30 to 500 Hz, and pause time between anode and cathode pulses from 0 to 5 ms, wherein the fraction of anode pulses with voltage amplitude from 350 to 500 V, duration from 50 to 300 mcs and repetition rate of pulses from 30 to 500 Hz and cathode pulses with voltage amplitude from 0 to 50 V, duration from 50 to 100 mcs and repetition frequency of pulses from 30 to 500 Hz is not more than 75 %, and the fraction of anode pulses with voltage amplitude from 500 to 600 V, duration from 50 to 300 mcs and repetition frequency of pulses from 30 to 500 Hz and cathode pulses with voltage amplitude from 0 to 100 V, with duration of 50 to 100 mcs and repetition frequency of pulses from 30 to 500 Hz is not less than 25 %.
EFFECT: controlling the rate of obtaining coating on different sections of the surface of the article, which enables to obtain uniform thickness of the coating on the article or the required thickness on its sections.
6 cl, 1 dwg, 2 tbl, 10 ex
