14th International Conference on Shot Peening

A hybrid approach for simultaneous ultrasonic peening and polishing of selective laser melted Inconel 625 components

Arun Prasanth Nagalingam, Nikhil Godsay, Hemanth Kumar, Sharan Gopasetty, Vijay Santhanam, Abhay Gopinath, Yeo Swee Hock.

Abstract

Fatigue failure of aerospace components due to the surface and sub-surface defects is critical. Compressive residual stress resulting from peening and surface roughness reduction through polishing improves a component’s fatigue life. However, peening and polishing are time-consuming and costly. This work investigates a hybrid approach to simultaneously peen and polishes the selective laser melted Inconel 625 components using ultrasonic methods. This hybrid approach improves a previously developed ultrasonic cavitation abrasive polishing (UCAF) process. Steel shots are added to the working chamber of the existing UCAF process. Ultrasonic excitation of steel shots and micro abrasives targeted to bombard the component surface is thought to induce compressive residual stresses and simultaneously reduce surface roughness. The residual stress, surface texture, material removal, microstructure characteristics, and fatigue life of the component are investigated and discussed.