Low temperature corrosion resistant aluminum and aluminum coating composition

A concentrated aluminum alloy or aluminum conversion coating composition for dilution to provide a low temperature conversion coating composition having a pH of from about 1.0 to about 4.0 comprising:

• 0% hexavalent chromium,
• alkali metal permanganate in an amount to provide a final aqueous conversion coating composition having at least 760 ppm of permanganate, and
• a halide in an amount to provide a halide ion concentration of at least about 100 ppm of halide.

A method of providing a corrosion resistant aluminum alloy or aluminum article that has no pitting when shortly after being coated is placed in a salt-spray at 95.degree. F. according to ASTM specification B-117-94 for 100 hours of exposure comprising;

• providing a low temperature conversion coating composition having as essential ingredients, water, 0% hexavalent chromium, an alkali metal permanganate providing at least 760 ppm permanganate, alkali metal or aluminum halide providing at least 100 ppm of halide, and a pH of from about 1.0 to about 4.0
• coating at said low temperature an aluminum alloy or aluminum article with said coating composition.

A method of providing a corrosion resistant aluminum alloy article comprising:

• providing a low temperature conversion coating having as essential ingredients, water, 0% hexavalent chromium, an alkali metal permanganate providing at least 760 ppm permanganate, alkali metal or aluminum halide providing at least 100 ppm of halide, and a pH of from about 1.0 to about 4.0;
• and
• coating at said low temperature an aluminum alloy or aluminum article with said coating composition to provide the aluminum alloy or aluminum article that has no pitting when placed in a salt-spray at 95.degree. F. according to ASTM specification B-117 for 100 hours of exposure within 10 minutes of being coated.