0000000000230195
AUTHOR
Olivier Neel
Numerical modelling of the galvanic coupling in aluminium alloys: A discussion on the application of local probe techniques
Abstract A discussion is proposed on the determination of the input values and the experimental validation of finite element modelling of the galvanic coupling in aluminium alloys by local probe techniques such as the Scanning Vibrating Electrode Technique (SVET) and the microcapillary electrochemical cell (microcell). Polarization curves obtained by the microcell were introduced as input conditions in the model based on Laplace or Nernst–Planck equation. SVET measurements were performed to determine the coupling current distribution on an Al/Al4%Cu bimetallic system. Agreement was found between simulated and experimental current distributions depending on the input conditions and the solve…
Simulation of pH-controlled dissolution of aluminium based on a modified Scanning Electrochemical Microscope experiment to mimic localized trenching on aluminium alloys
Abstract Some constituent intermetallic (IMPs) particles at the surface of aluminium alloys are considered as preferential sites for the initiation of structural corrosion resulting in localized trenching around the particles and the surrounding Al matrix. In this work, a modified scanning electrochemical microscope (SECM) experiment was used to induce such phenomena via a local alcalinisation on 200 nm thick aluminium coatings promoting their local dissolution in an aerated 0.1 M NaCl electrolyte. The local alcalinisation was induced by the oxygen reduction reaction on the tip of a SECM which mimics the surface of an isolated IMP. From a phenomenological point of view, reproducible cylindr…