Influence of addition of microsized alumina particles on material damage induced by vibratory cavitation erosion

It is well-recognized that the presence of solid particles in cavitating liquids can modify the hydrodynamic conditions that operate in hydraulic machinery, increasing surface damage and mass removal of the affected materials. This effect is commonly attributed to the combined contribution of both cavitation and solid particle erosion. In this work, alpha-brass and an aluminum alloy exposed to ultrasound-induced cavitating media containing different concentrations of microsized alumina particles were studied. In order to characterize the response of the material under cavitation attack, mass loss rate, surface hardening and microstructural morphologies in the incubation period were examined. The influence of the addition of microsized particles on mechanical degradation induced by cavitation is discussed in this paper in connection with the effect of direct particle impingements and alterations of cavitation conditions.