IMPROVED TRIVALENT CHROMIUM-CONTAINING COMPOSITION FOR USE IN CORROSION RESISTANT COATINGS ON METAL SURFACES

摘要

A low sludge trivalent chromium based conversion coating bath is provided which forms corrosion resistant coatings on aluminum and aluminum alloys by immersion in aqueous solutions containing trivalent chromium ions and fluor ometallate ions followed by optional rinsing. Trivalent chromium coated alum inum also serves as an effective base for paint primers.