Inelastic damages by stress wave on steel surface at the incubation stage of vibration cavitation erosion

In cavitation erosion, stress waves will be generated and propagated in the solid when a collapse impingement is acted on it. The cavitation damages on the solid surface are considered to be under the effect of the stress waves. An ultrasonic vibration cavitation erosion experiment was performed on a polished steel specimen, and not only the plastic deformations but also the brittle fractures appeared on the surface at the incubation stage of cavitation erosion. Some characteristics such as the hemispherical shape of the crater, intergranular fractures and subsurface comminution make the damages distinguishable from the common plastics deformations, and they are thought to be the results of shear waves. Thus, stress waves are proved to take part in the cavitation erosion, and they bring some special damage styles depending on the conditions of the impaction and mechanical properties of the specimen. (C) 2008 Elsevier B.V. All rights reserved.