Characterization of a water peening process

A traversing water jet was used to impact the surface of 1100 series aluminum specimens in an effort to generate compressive residual stresses on the surface. Stresses induced by the water peening operation were measured using X-ray diffraction, and compressive stress increases as large as 60 percent of the monotonic yield strength resulted Surface roughness and hardness were also measured Finite element modeling of a stationary water jet impinging on an elastic-plastic half-space was performed to characterize the water peening process. Surface residual stresses were found to be a result of sub-surface plastic deformations.