Abstract: Composition and process for treating aluminum, aluminum alloys and anodized aluminum substrates to improve the corrosion resistance and adhesive bonding strength of the aluminum substrates. The process comprises pre- or post-treating said aluminum with an acidic aqueous solution comprising, per liter of solution, from about 0.1 to 22 grams of at least one fluorometallate, about 0.1 gram up to the solubility limit of a water soluble cationic or divalent zinc compound and, optionally, effective amounts of water soluble thickeners and/or surfactants.

Abstract: Process of seal coating phosphoric acid anodized aluminum and aluminum alloys to improve the corrosion resistance and maintain the adhesive bonding properties. The process comprises post-treating phosphoric acid anodized aluminum and its alloys with an acidic aqueous solution comprising, per liter of acidic solution, from about 0.01 to 22 grams of a water soluble trivalent chromium compound, about 0.01 to 12 grams of an alkali metal hexafluorozirconate, about 0.0 to 12 grams of at least one alkali metal tetrafluorosilicate and/or an alkali metal hexafluoroborate, from about 0.001 to 10 grams of at least one water soluble divalent zinc compound and from 0.0 to 10 grams of a water soluble thickener and/or water soluble surfactant.