METHOD OF OBTAINING PROTECTIVE COATINGS ON MAGNESIUM ALLOYS Russian patent published in 2015 - IPC C25D11/30 

FIELD: chemistry.

SUBSTANCE: method includes plasma-electrolytic oxidation (PEO) of alloy surface in water electrolyte, which contains sodium silicate and sodium fluoride, for 10-15 min in bipolar mode with equal duration of anode and cathode polarisation periods, with effective current density 0.5-1.0 A/cm² and uniform increase of voltage from 0 to 250-270 W during the period of anode polarisation of alloy and constant value of voltage - 25-30 W during period of cathode polarisation. Alloy with applied PEO-coating is submerged at room temperature for 100-120 min into solution of 8-oxyquinoline C9H7NO, obtained by its dilution in water with heating to 90°C with addition of NaOH to pH value 12.0-12.5. Obtained coating is subjected to thermal processing at 140-150°C for 100-120 min.

EFFECT: reduced rate corrosion of obtained protective coatings and increase of their service term in atmosphere with high humidity, which contains chloride-ions, due to coating ability to self-recovery.

2 cl, 3 ex