Surface treatment for aluminum and aluminum alloys
AssigneeChemical Systems, Inc.
InventorsNarayan Das, Joy M. Schaefer
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Abstract
A low pH solution and a method for conversion coating aluminum and aluminum alloy surfaces, as well as the coated surfaces themselves, utilizing zirconium, fluoride and nickel and, optionally, fluorophosphate.
Claims15
An aqueous coating solution for forming a coating on aluminum and aluminum alloy surfaces consisting essentially of at least about 0.025 grams/liter of zirconium, at least about 0.050 grams/liter of fluoride ion, at least about 0.025 grams/liter of nickel and sufficient acid to adjust the pH to the range of about 1.2 to about 2.5.
An aqueous coating solution for forming a protective, flexible coating on aluminum and aluminum alloy surfaces consisting essentially of from about 0.05 to about 0.120 grams/liter of zirconium, from about 0.100 to about 0.150 grams/liter of fluoride, from about 0.075 to about 0.150 grams/liter of nickel, from about 0.100 to about 0.150 grams/liter of a fluorophosphate compound, from 0.075 to about 0.150 grams/liter of a polyhydroxy compound having up to 7 carbon atoms and sufficient acid to adjust the pH of the solution to the range of about 1.5 to about 2.0.
A method for coating aluminum and aluminum alloy surfaces comprising contacting said surfaces with an aqueous coating solution consisting essentially of at least about 0.025 of zirconium, at least about 0.050 of fluoride, at least 0.025 of nickel and sufficient acid to adjust the pH of said solution to the range of about 1.2 to about 2.5.
Dependencies are inferred from the claim text.