0000000000064397
AUTHOR
R. Bonzom
Droplet cell investigation of intergranular corrosion on AA2024
An original method combining a droplet cell with direct optical interrogation of the reverse side of a 50μm thick foil AA2024 has been tested to evaluate the possible analysis of the current during intergranular corrosion tests. The foil microstructure and the selected orientation were suitable for recording the current generated during the propagation in volume of a well-defined grain boundary trace. Even if it is impossible to reach a charge and mass balance from these preliminary attempts, it was demonstrated that it is possible, despite hydrogen evolution, to record a current transient resulting from the full penetration of an intergranular path. Keywords: Intergranular corrosion, Alumi…
Real-Time Monitoring of Intergranular Corrosion Damage on AA2024
The total porosity induced by the intergranular corrosion was selected as a monitoring parameter to follow in real-time the defect propagation of AA2024. The pertinence of eddy current (EC) probing has been tested on very thin foils of AA2024 (30 μm in thickness) in immersion conditions under potentiostatic control and in atmospheric conditions simulated by controlled salt spray experiments. Combining this nondestructive evaluation technique with a direct optical interrogation of the backside of the test specimen (derived from the foil penetration technique) allows one to discuss the contribution of both the dissolution in the depth and along the grain boundaries to the total porosity. In i…