METHOD OF FIRMING ANODE-OXIDE COATING OF ITEM OUT OF ALUMINIUM AND ITS ALLOYS Russian patent published in 2010 - IPC C25D11/20 

FIELD: metallurgy.

SUBSTANCE: invention refers to method of firming anode-oxide coating on surface of items out of aluminium and its alloys and is designed for upgrading their corrosion resistance with simultaneous detection of surface defects of metal. The invention can be implemented in aircraft, air space engineering, in instrument making industry and in building for production of protective coating on items out of aluminium alloys. The method consists in treatment of an item corresponding to a cathode at constant current in electrolyte of the following composition, g/l: sulphuric magnesium ((MgSO₄) 5-20, iron chloride (FeCl₂) 0.1-0.3, acetic ammonium (NH₄CH₃COO) 0.001-0.1 and water up to 1 litre. Treatment of the item is carried out on a cathode at density of constant current 0.1-0.2 A/dm² during 3-5 minutes and temperature 18-22°C.

EFFECT: facilitating high protective properties of coating and possibility of detecting defects of surface of anode-oxidisable items.

2 cl, 1 tbl, 1 ex