Abstract: In the process of sealing decorative anodized aluminum oxide coatings in hot aqueous solutions, superior results are obtained when the sealing solutions contain 1-phosphonopropane-1,2,3-tricarboxylic acid, 1,1-diphosphonopropane-2,3-dicarboxylic acid, and/or alkali metal and/or alkanolamine salts of these acids. The presence of these acids or their salts prevents the formation of bloom and allows shorter sealing times with equivalent quality, and the addition of as little as 1 ppm of aluminum ions to such solutions also prevents iridescence.

Abstract: A process and composition for producing colorless, cold-sealed, anodized aluminum or aluminum alloy surfaces. The composition comprises an aqueous solution containing nickel ions and a solution of at least one azo or azo metal dye, the colors imparted by the nickel ions and dye offsetting each other.

Abstract: A process for sealing anodically produced oxide layers on aluminum and aluminum alloys by treating them with an aqueous solution at a temperature between about 90.degree. C. and its boiling point, wherein the aqueous solution has a pH of from about 4 to about 8 and and contains from about 0.0005 to about 0.5 g/l of at least one phosphinocarboxylic acid or its water-soluble salt.

Abstract: In the process of treating an aluminum or aluminum alloy surface which comprises anodically oxidizing the surface and subsequently sealing the surface, the improvement consisting of sealing in an aqueous solution at a temperature between 90.degree. C and the boiling temperature of the solution, said aqueous solution having a pH value of from 4 to 8 and containing from 0.0005 to 0.2 gm per liter of cycloaliphatic or aromatic polycarboxylic acid or water-soluble salt thereof, said cycloaliphatic or aromatic polycarboxylic acid having 4 to 6 carboxyl groups.