Patterned Laser Shock Peened Residual Stress measurment via Energy Dispersive Diffraction and High energy x-ray diffraction

Residual Stress remains one of the greatest challenges in metal additive manufacturing (MAM) driving distortion, cracking, and reduced structural reliability in printed parts. Femtosecond laser shock penning (FLSP) is a technique that offers a post processing pathway towards surface residual stress reduction. However, understanding of spatial effects of FLSP at different processing parameters remains unknown. In this work, patterned FLSP are applied to thin wall additive manufacturing samples to determine the geometry of controllable residual stress distribution from precise FLSP.

Residual stress distribution was measured with both High Energy X-ray Diffraction and Energy Dispersive Diffraction to generate high resolution maps of residual stress and compare measurement techniques. Results demonstrate that surface FLSP-induced residual stress fields can be geometrically controlled, with clear changes measured stress distributions in the patterns scanned. These results establish FLSP for patterned residual stress control on the surface of thin wall samples. This work aims to provide a framework to determine geometric effect of FLSP to enable tailoring of shock peen scans for optimal stress distribution.