摘要 |
Compositions and process for post-treating aluminum and aluminum alloy coated steel substrates to improve the corrosion resistance and adhesive bonding strength of the aluminum coated substrates. The composition comprises treating the aluminum or aluminum alloy coated steel substrates with an acidic aqueous solution comprising, per liter of solution, from about 0.1 to 22 grams of a hexafluorozirconate, from about 0.1 gram up to the solubility limit of a water soluble cationic zinc compound and, optionally, effective amounts of water soluble thickeners and/or surfactants.
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