| 摘要 |
<p>A composition for imparting a corrosion-resistant coating to aluminium or aluminium alloys comprises an acid aqueous solution containing as its sole coating-forming ingredients ions of hexavalent chromium and fluorine in proportions sufficient to form a continuous adherent coating, the solution also containing zirconium, titanium and/or tin. The latter may be added as fluozirconic, fluotitanic, or fluostannic acids or soluble salts thereof. Examples include aqueous solutions of chromic acid, potassium fluozirconate and ammonium borofluoride; chromic acid, potassium fluozirconate, boric acid and ammonium bifluoride; chromic acid, hydrofluoric acid and titanium trichloride; ammonium bifluoride, chromic acid and stannic chloride with or without titanium trichloride and/or zirconium nitrate; diammonium silicofluoride, chromic acid and zirconium nitrate. Specification 328,485, [Class 82 (ii)], is referred to.</p> |
