This paper reports the findings of fatigue crack growth measurements on a 2014 aluminium alloy that had been anodised using the recently developed boric acidsulphuric acid process. The results demonstrate that fatigue crack growth rates in this alloy can be markedly enhanced by the presence of a thin anodic oxide film. This enhancement can be explained in terms of reduced plasticity induced closure assisted by surface cracking of the brittle oxide film ahead of the propagating fatigue crack.
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