| 摘要 |
PROBLEM TO BE SOLVED: To provide a composition for surface treatment of aluminum and an aluminum alloy, which is excellent in corrosion resistance, especially pitting corrosion resistance. SOLUTION: The chromium-free composition for surface treatment of aluminum and the aluminum alloy contains a lithium compound, a carbonate compound and at least one oxidizing agent chosen from the group consisting of lithium, sodium, potassium or ammonium salts of peroxodisulfuric acid, nitric acid, nitrous acid and bromic acid. Reduction treatment using the composition differs from a conventional reduction treatment technique using lithium ion and is characterized by developing conversion film within a passivation potential range of the aluminum alloy in a liquid mixture of strong alkaline lithium and carbonate ion. COPYRIGHT: (C)2005,JPO&NCIPI
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