AQUEOUS CHEMICAL CONVERSION TREATMENT AGENT FOR ALUMINUM OR ALUMINUM ALLOY, CHEMICAL CONVERSION TREATMENT METHOD, AND CHEMICAL-CONVERSION-TREATED ALUMINUM AND ALUMINUM ALLOY

摘要

[Problem] To provide a hexavalent chromium-free chemical conversion treatment technique which can steadily impart excellent corrosion resistance to aluminum and aluminum alloys, particularly an aluminum die cast material, which have various surface conditions. [Solution] An aqueous chemical conversion treatment agent for treating the surface of aluminum or an aluminum alloy, said aqueous chemical conversion treatment agent being characterized by being prepared by adding a chitosan compound (A), at least one component (B) selected from the group consisting of a water-soluble trivalent chromium compound, a water-soluble titanium compound and a water-soluble zirconium compound and a nitrate ion (C) together, and also characterized by additionally containing a soluble fluorine component (D).