Coupling bubble and material dynamics to model cavitation peening and pitting

Abstract

The effects of cavitation bubble dynamics on material peening and pitting is investigated numerically using a coupled fluid and material dynamics approach. The model is applied here to the study of peening and pitting of metallic materials resulting from non-spherical cavitation bubble collapse near the material. Bubble reentrant jet impact and shock wave emission from the jet impact and from the collapse of the remaining bubble ring can induce permanent micro-deformation, pitting, and residual stresses, which modify the roughness of the material and harden it through pre-stressing. These effects are investigated through a parametric study for different bubble material standoff distances. Quantities such as bubble collapse peak pressure, pit depth, and residual stresses depend strongly on bubble standoff distance, which is an important factor in whether hardening or erosion of the material occurs.