METHOD FOR OBTAINING COATINGS ON SURFACES OF BLIND HOLES OF PARTS FROM ALUMINIUM ALLOYS Russian patent published in 2013 - IPC C25D11/06 

FIELD: machine building.

SUBSTANCE: method involves electrochemical oxidation of parts with blind holes, which is implemented during 30-100 minutes; at that, the solution, in which oxidation is performed, is pumped during the half of the specified oxidation period of time to the part hole through a stainless steel nozzle located inside the part hole, so that the solution flows to the bath through the gaps between surfaces of the part hole and nozzle, and during the second half of the specified time the solution is pumped off the part hole through the nozzle so that the solution is taken from the bath to the above gaps; at that, part and nozzle are connected to opposite poles; flow of the solution inside the part hole is maintained in laminar mode at the solution flow rate of 0.1-1.6 l/min per 1 dm² of the surfaces of the hole; at that, nozzle is inserted into the part hole so that a gap of 4-6 diameters of the nozzle hole can be provided between end of nozzle and bottom of the part hole when the solution is being pumped to the part hole and 1-3 diameters of the nozzle hole when the solution is being pumped off.

EFFECT: increasing thickness, breakdown voltage and electric resistance of coatings in holes of parts.

6 tbl, 5 dwg, 2 ex