Abstract
Corrosion films formed on aluminum in hot salt water (100 to 177 C) after short time tests of thirty seconds to one hour were studied by transmission electron microscopy and diffraction. It was concluded from observation of 6061, 5454, 2024, Al-1.52Mn and Al-1.66Ni alloys that one controlling factor in the initiation and growth of the outer film of the duplex oxide film is the alloy composition. The outer film formed earlier on alloys containing copper and the film growth was also more rapid on these alloys. Additions of magnesium, manganese and nickel retarded this outer film formation but with nickel additions, pitting attack was more severe and deposition of copper from solution was increased. The formation and growth of the outer film was slowest on the 5454 alloy which was also the most resistant alloy tested.
