Research on the ultrasonic vibration-assisted short electric arc milling process of Inconel 718

This study introduced a new ultrasonic vibration–assisted short electric arc machining method to improve the machining quality of workpieces. This method mitigated abnormal discharge phenomena such as short circuits, partial discharge, and secondary discharge caused by particle bridges formed between electrodes and workpieces owing to ineffective chip removal in conventional short electric arc machining. After both standard short electric arc and composite processing, the macroscopic characteristics and microscopic morphology of the workpiece were compared through experiments. Moreover, the surface morphology, roughness, and elemental energy spectrum of the workpiece were examined and analyzed through ultra-depth-of-field microscopy, electron scanning, and other methods. The results revealed changes in the surface morphology of the workpiece after the integration of a short electric arc machining and ultrasonic vibration. With the introduction of ultrasonic vibration, the workpiece surface exhibited disorder and uniformity, along with a significant reduction in the number of electrical corrosion pits and surface microcracks. Consequently, the thickness of the recast layer decreased by half, and the surface roughness decreased by over 16%, achieving a maximum reduction of more than twice the original state. Additionally, the surface elements of the material were modified. This study introduces a new method for advancing short electric arc technology to improve processing quality, material modification, and technological coupling.