Electrochemical Corrosion of an Aluminum Alloy in Cavitating Ethylene Glycol Solutions
SourceAluminum alloys that are used in engine cooling systems with high velocity fluids are particularly susceptible to damage by cavitation. Electrochemical methods were used successfully to determine the contribution of corrosion to the total metal damage caused by ultrasonically-induced cavitation. Measurements were made for an aluminum casting alloy immersed in hot ethylene glycol solutions, which were either well-inhibited or poorly inhibited against corrosion. Results of controlled-potential tests showed that the resistance of aluminum to cavitation damage in various media may be evaluated electrochemically, and that the magnitude of the effect of corrosion on cavitation damage can be as high as 75 percent of the total damage when cavitation is induced by ultrasonics. The metal potential, the corrosivity of the medium, and the inhibitor content of the ethylene glycol solution affect the nature and degree of cavitation damage.