Bubble-induced cavitation effect upon solid surfaces

The dynamic damage during cavitation erosion is of a spall nature and results from the interference of rarefaction waves. Spherical shock waves, which arise due to the collapse of cavitation bubbles, generate shock waves in the target. The rarefaction waves appear when the velocity of the contact boundary decreases below the sound velocity in the target material and the shock waves emerge at the free surface. The coordinate of the rarefaction wave formation site determines the zone of potential damage. The interference of rarefaction waves creates the spall channel crack, near which the coaxial cylindrical cracks are formed-as a rule, in the dynamic fatigue regime-in the course of subsequent loading.