METHOD OF PRODUCING OF BLACK WEAR-RESISTANT ANTI-CORROSION COATING ON ALUMINIUM AND ALUMINIUM BASED ALLOYS BY METHOD OF MICROARC OXYDATION

摘要

FIELD: metallurgy.SUBSTANCE: method includes microarc oxidation of the part in alkali-silicate electrolyte at alternating current density from 8 to 40 A/dmof microarc oxidation, wherein to the electrolyte additionally alkali metal ferrocyanide and alkali metal hexametaphosphate are added at the following components content, g/l: alkali 1-4, alkali metal ferrocyanide 5-10; alkali metal hexametaphosphate 2-4, technical liquid glass with content of c=15/m±0.25, where m is modulus of the , technical liquid glass, wherein after electricity passage through one litre of electrolyte in amount of 7.5-8.5 A·h the alkali metal ferrocyanide is added in amount of c, determined from ratio c=0.13·c, where cand care initial and added content of the alkali metal ferrocyanide in the alkali-silicate electrolyte, wherein the process of microarc oxidation continues upon completion of the coating growth, and stop of burning of the microarc discharges during time period ?, determined as per the equation: ?=6000/(|i|·|t|)±1, min, where |i|, |t| are absolute densities of set alternating current in A/dmand electrolyte temperature in °C, respectively.EFFECT: increased coating uniformity through thickness, increased corrosion strength, adhesion, coating hardness and duration of the electrolyte operability upon use of simple unit and high process capacity.4 cl, 2 ex