Model to predict intergranular corrosion propagation in three dimensions in AA5083-H131

Abstract

A three-dimensional (3-D) granular model that has the capability of predicting time-dependent intergranular corrosion (IGC) damage propagation depths in AA5083-H131 exposed to 0.6 M NaCl solution under potential control is presented. The geometry of grains and degree of sensitization (DoS) of grain boundaries were utilized as inputs, organized in a database, which informed the model to produce IGC depth distributions. The dependencies of IGC depth with exposure time, DoS, and orientation of propagation, both in terms of propagation kinetics and damage morphology, are outputs from the model. The model was calibrated by comparing outputted damage depths to IGC depth data from experiments. Model validation was achieved by comparing the predicted to experimental IGC depths based on image analyses of metallographic cross-section of AA5083-H131 exposed under the same conditions. The relevance and limitations of the current version of the model are discussed.

The influence of Zn2+ on stress corrosion cracking severity in a highly sensitised Al–Mg alloy

“…The acidification of the crack tip that occurs through the metal cation hydrolysis reactions increases the hydrogen overpotential at the crack tip which, in turn, enables local hydrogen adsorption and diffusion into the fracture process zone, where the hydrogen promotes decohesion of the grain boundary and/or at the interface of the intergranular β particle and the matrix. This mechanism has been recently supported through experimental work in a variety of saline environments and alloy sensitisation conditions [17,25,26,28,32,33] and has been theoretically supported through hydrogen-enhanced decohesion modelling [17,25,26].…”

Influence of the grid cell geometry on 3D cellular automata behavior in intergranular corrosion

“…Results showed that SROMs are more computationally efficient than Monte-Carlo simulations and then constitute an accurate alternative for this purpose. Other models focused on the material microstructure, having as input parameters the geometries and grain orientation [7][8].…”

Intergranular Corrosion and Microstructural Evolution in a Newly Designed Al-6Mg Alloy

“…The β-phase formation is usually observed at grain boundaries (GB), sub-grains, intermetallics, dislocations and other defects. Generally, the sequences of β precipitation have been reported as follows [14][15][16]:…”