Erosion–corrosion of aluminium alloys in ethylene glycol–water solutions in absence and presence of sand particles

Abstract

The erosion–corrosion of aluminium alloys in ethylene glycol–water solutions that simulated the automotive coolant was studied by a rotating cylinder electrode (RCE) through the measurements of potentiodynamic polarisation curves, electrochemical impedance spectroscopy and weight loss. In the absence of sand particles, the turbulent flow developed on RCE produces weakening effects and damage to the oxide film on the Al electrode, which becomes more active with the increasing fluid flow, as indicated by the negative shift of corrosion potential and the decreasing film resistance. In the presence of sand particles, both the turbulent flow of solution and the mechanical impingement of sand particles contribute to the weakening and damage to the oxide film. However, the interfacial reaction mechanism is not changed upon the sand addition. In the ethylene glycol–water–sand solution, weight loss of Al alloys is mainly due to the contribution of the mechanical erosion of sand particles. The corrosion induced weight loss is negligible.