Aluminum products having improved corrosion resistance

Abstract From the Canadian patent

1-, Abstract, A corrosion resistant aluminum article is described. It includes a main body portion formed of an aluminum alloy containing no more than 0.4% iron, no more than 0.15% silicon, from about 0.1% to about 0.6% copper and from about 0.7% to about 1.5% manganese. The corrosion resistance is provided by a silicon-rich band of dense precipitate formed in the alloy adjacent at least one face thereof. This band has a thickness of about 20-50 µm and there is substantially less manganese in solid solution in the band than in the alloy outside the band. To form the band a silicon-, containing layer is applied to a surface of the alloy body to be protected and the composite thus formed is …