Classification of regimes determining ultrasonic cavitation erosion in solid particle suspensions

Although the factors that influence ultrasonic cavitation erosion in solid particle suspensions have been extensively studied, the role that solid particles play in the cavitation process remains poorly understood. The ultrasonic cavitation erosion of AISI 1045 carbon steel was studied in the presence of monodisperse silica particles (10-100 μm, 0.5-20 vol%) suspended in transformer oil. Based on our results, we propose an overview of the possible influencing mechanisms of particle addition for specific particle sizes and concentrations. Four major regimes, namely a viscosity-enhancing regime (V), a particle-impinging regime (I), a particle-shielding regime (S), and a nuclei-adding regime (A) are identified, and their dependence on suspended particle characteristics is analyzed. The VISA regimes, in essence, reflect the viscous and inertial effects of suspended particles, and the way in which particle-particle interactions and heterogeneous nucleation affect erosion. This regime-based framework provides a better understanding of the dominant factors controlling the erosive wear caused by cavitation in the presence of solid particles, and provides a guide for erosion prediction and prevention.