Statistical Modeling of Minimum Intergranular Corrosion Path Length in High-Strength Aluminum Alloy

In this article a brick wall model is developed to describe the relationship between the minimum intergranular corrosion path length and the aspect ratio of grains of high-strength wrought aluminum alloy AA2024-T3. We study the distribution of the horizontal distance that a corrosion path will travel in the metal and fit the model to an actual corrosion dataset using the method of moments. The distribution of the horizontal distance of a corrosion path along a given grain is assumed to be uniformly distributed given the length of the grain, which is itself modeled by a gamma distribution. A modified brick wall model is proposed that also imposes a distribution on the vertical distance traveled by the corrosion path. Computer simulation is used to evaluate the fit of these models.