High-speed imaging of cutting and electrical discharge machining (EDM) in thin metals and fluids using high-intensity 100 keV x rays

Conventional machining methods, such as cutting and electrical discharge machining (EDM), have significantly contributed to the manufacturing industry for a long time. Despite their extensive development history, the underlying machining mechanisms remain unclear because direct observation of actual cutting and EDM processes inside metals and fluids has been impossible. In this study, we employed an intense, high-energy x-ray beam from an undulator source to visualize the motion of tools and the processing surfaces during cutting and EDM processes. The 100-keV x rays with a flux density of 1013 photons/mm2 enabled non-destructive observation inside metals at a high frame rate of 5000 fps. This study demonstrates that conventional metal machining processes, including interactions under fluids, the motion of tools, and the change of the processing surface during drilling and small-hole EDM, can be observed clearly. The developed x-ray imaging system can be applied to analyzing various actual machining phenomena in both traditional and non-traditional processes.