Abstract
The rapid phenomenon happening at the interelectrode gap (IEG) of 50 microns in the micro electric discharge milling (μED-milling) is complex. Various techniques such as computational fluid dynamics (CFD), scanning electron microscope (SEM), and the high-speed camera is utilized to study the behavior. As multiple process occurs in microseconds, high-speed video camera is useful to capture rapidly occurring events. The actual process images at the interelectrode gap (IEG) of the micro electric discharge milling (μED-milling) is captured using a high-speed video camera pco. dimax HS4 highspeed CMOS camera. This camera can capture images at a maximum frame rate of 46746 fps at a lower resolution of 320 × 200. The images of spark and dielectric flow are captured at a high resolution and a frame rate of 2277 fps. The high-speed images show sparking to be continuous along the periphery of the tool which is unique in μED-milling. The obtained images of the spark are used to find the IEG size and the bubble motion is used to calculate the velocity of the dielectric. The dielectric motion is majorly vortex flow and is observed at the back of the tool due to tool rotation. The SEM images show spherical debris particles deposited on the machined surface. The size of the debris particles depends on the input energy. Larger crater is formed on the workpiece surface at high energy levels which eventually forms large size debris particles. All the techniques used provide useful information and shows close resemblance.
