METHOD OF MICRO ARC OBTAINING OF COMPOSITE COATING ON ALUMINIUM AND ITS ALLOYS Russian patent published in 2012 - IPC C25D15/00 C25D11/12 

FIELD: metallurgy.

SUBSTANCE: method involves micro plasma oxidation in pulse anodic-cathodic mode with duration of groups of anodic pulses of 50 ms, cathodic pulses of 40 ms, pauses between them of 10 ms and ratio of average anodic and cathodic currents of 1.1 : 0.9 in water solution of electrolyte, which consists of three solutions, series oxidation in them during 10 minutes, at the following component ratio, g·l^-1, in the first solution: sodium hydroxide 0.3-0.5, sodium metasilicate 3.0-4.0, water suspension of Teflon F-4MD or F-4D 44.0-50.0; in the second solution: sodium hydroxide 0.8-1.0, sodium metasilicate 6.0-8.0, water suspension of Teflon F-4MD or F-4D 44.0-50.0; in the third solution: sodium hydroxide 1.8-2.0, sodium metasilicate 11.0-15.0, water suspension of Teflon F-4MD or F-4D 44.0-50.0.

EFFECT: simplification of the technology of the process for obtaining oxide composite coatings; increasing corrosion resistance, wear resistance and antifriction properties of aluminium surface and its alloys.

1 tbl, 1 dwg, 2 ex