Surface Strengthening by Water Jet Peening

Abstract

Fatigue strength improvement of metallic components can be obtained by generating compressive residual stresses in sub-surface layers, for example by shot peening. The main drawback of conventional shot peening technique is related to surface integrity deterioration. Water Jet Peening is an innovative surface strengthening process which has the main advantage of a negligible influence on surface roughness and texture. Moreover the high accessibility of water jet could also offer the opportunity of processing parts with complex geometry. Since inaccurate choice of parameters could cause erosion, the improvement of fatigue strength could be neutralized by the presence of micro-cracks on the surface. The present study introduces an experimental analysis on water jet peening parameters. Results show that parameters can change in a wide range without affecting surface integrity. This result could be considered as an important step toward industrial application of this new technology. Moreover the paper analyses parameters influence on residual stress induced by the process.