Multistage anodising process of aluminium.

摘要

Multiple anodising of an aluminium element is carried out by (a) surface polishing degreasing or pickling and water rinsing, (b) anodising in an aq. electrolyte contg. 180-200 g/l sulphuric acid and 5-10 g/l aluminium sulphate at 12-15 V d.c., followed by cleaning by immersion in water; (c) colouring in a demineralised water bath contg. (in)-organic pigments (for chemical colouring) or metal salts (for electrolytic colouring), followed by cleaning by immersion in water; (d) sealing in boiling demineralised water; (e) selectively removing the anodised layer and rinsing by immersion in water; (f) re-anodising under the same conditions as in step (b) with corresponding colouring of the new anodised layer; and (g) sealing in boiling demineralised water.