| 摘要 |
<p>1291607 Colour anodizing aluminium CEGEDUR G P 19 Dec 1969 [23 Dec 1968] 61895/69 Heading C7B An article of Al or Al alloy, e.g. containing Si, Mg, Mn, is provided with a coloured (e.g. yellow or brick) protective layer by anodizing it to form a porous alumina layer on the article, electro-depositing coloured particles of a metal or metal compound in its pores using A.C. in a bath containing in solution a salt of the metal to provide a temporary colour effect, modifying this effect by anodic treatment using D.C. or rectified unfiltered current in an aqueous sodium thiosulphate solution, and sealing the alumina pores with boiling water to fix the final colour finish. Anodizing may be effected in an aqueous H 2 SO 4 bath and colouring in a H 2 SO 4 solution of a metal salt, e.g. of Cu, Ni, Co, such as CuSO 4 ; the boiling water preferably contains nickel acetate. In colouring, the counter-electrode may be of the constituted metal of the particles or of steel. Prior to coating, the article surface may be polished or satinized.</p> |
