Applied Surface Science, Vol.351, 997-1003, 2015
Corrosion resistance and high-cycle fatigue strength of anodized/sealed AA7050 and AA7075 alloys
AA7075 and AA7050 alloy bars were heat treated and prepared for different anodization treatments to obtain an anodic aluminum oxide (AAO) film with a thickness in the range 9-11 mu m. Subsequently, the samples were sealed in hot water. Potentiodynamic tests were conducted to obtain different E-corr and I-corr values. Factors affecting the corrosion resistance of different samples are discussed in this paper. They include the energy consumed in Steps 2 and 3 during anodization and constituted oxide phases and bubbles formed in the AAO film. The anodized and sealed 7075 samples showed corrosion resistance superior to that of the 7050 samples. However, the 7075 alloy samples absorbed more hydrogen from their matrix compared with the 7050 alloy samples, causing them to develop lower fatigue strength at 1 x 10(7) life cycles. (C) 2015 Elsevier B.V. All rights reserved.