PROCEDURE FOR APPLICATION OF COATING Russian patent published in 2010 - IPC C25D11/08 C25D15/00 

FIELD: metallurgy.

SUBSTANCE: invention refers to electroplating. The procedure consists in micro-arc oxidation (MAO) during 55-85 min in solutions containing caustic potassium, boric acid and methylene blue at density of current 25…35 A/dm². Parts are transferred and oxygen is supplied to their surface. Laser radiation is applied to a jet of oxygen at distance of 1-2 mm off oxidised surface. Further parts are heated. Also prior to MAO, solutions are heated to 70…80°C, mixed and cooled to 15…20°C. MAO is performed in four stages: during 10 min in solution of caustic potassium 6…8 g/l, boric acid 40…50 g/l and methylene blue 0.5…0.8 g/l, further 15…20 min in solution of caustic potassium 6…8 g/l, boric acid 40…50 g/l, methylene blue 0.5…0.8 g/l, corundum (3…5 mcm) 40…60 g/l and chromium oxide 1…2 g/l, then 20…30 min in solution of caustic potassium 6…8 g/l, boric acid 40…50 g/l, methylene blue 0.5…0.8 g/l corundum (5…7 mcm) 40…60 g/l and chromium oxide 1…2 g/l, and finally in solution of caustic potassium 6…8 g/l, boric acid 40…50 g/l, methylene blue 0.5…0.8 g/l corundum (7…10 mcm) 40…60 g/l and chromium oxide 1…2 g/l. Further parts are heated to 380…400°C, and conditioned during 25…30 min at gradual drop of pressure 10…30 Pa at rate 3500…4000 Pa/min.

EFFECT: decreased power consumption, increased efficiency, thickness, hardness, breakdown voltage and electrical resistance of produced coating.

2 tbl, 6 dwg, 1 ex