Corrosion Behavior of 7A04 and 2A12 Aluminum Alloys in Hot and Dry Atmosphere Environment in Turpan

The corrosion behavior and mechanism of 7A04 and 2A12 aluminum alloys exposed for 1 year in the hot and dry atmosphere environment in Turpan were studied. The results of weight lose tests showed that the corrosion rate of 7A04 aluminum alloy was greater than that of 2A12. The results of scanning electron microscopy(SEM) and energy dispersive spectra showed that the corrosion products on the surface of the aluminum alloys were composed of aluminum oxides and hydroxides. After removal of corrosion products, the number of corrosion pits on 7A04 aluminum alloy was more than that on 2A12. The results of electrochemical impedance spectroscopy showed that the resistance and capacitance of corrosion product layer had large difference between the two kinds of aluminum alloys, 2A12 aluminum alloy with corrosion products had better corrosion resistance than 7A04 aluminum alloy.