Electrochemical measurement of erosion from individual cavitation events generated from continuous ultrasound

Abstract

Passivated electrode surfaces of aluminium and lead have been employed to investigate individual erosion corrosion events produced by ultrasound. Individual events are recorded with a resolution within the sub-millisecond time scale. The probability of the recorded events was found to fit with the expected physical model of the system. Distance dependence of the erosion corrosion currents recorded are reported showing that the active transient cavitation zone of the sound field employed is within the first ca. 5 mm of the sound emitting surface. The electrode material is also shown to have a marked effect on the distance dependence of surface erosion. The extent of surface damage, as the result of individual cavitation events, are calculated from the current time transients recorded on passivated lead electrodes.