Enhancing surface treatment performance of water cavitation jet peening by dissolving CO2

Abstract

Inducing compressive residual stress into surface layer is believed to enhance fatigue strength of materials. Water cavitation jet peening (WCJP) is recommended because of its high efficiency and uniform processing. This work proposes an enhanced WCJP technology by dissolving carbon dioxide (CO₂). Mass loss, Vickers hardness, surface profile, residual stress, cavitation pit and grain size of the processed Aluminum were investigated. Results indicate that appropriate CO₂ dissolution promotes cavitation peening with less surface distortion. The induced compressive residual stress is 28.6 % larger than pure waterjet peening. CO₂ content of 200 mg/L is recommended to obtain a desired peening performance.