Innovative Approaches to Increase Productivity in Sink Electrical Discharge Machining

Abstract

Electrical Discharge Machining (EDM) is a non-conventional machining process which utilizes spark erosion to remove workpiece material. Sink EDM refers to the use of prismatic or volumetric electrodes to create cavities or pockets within a workpiece. Sink EDM offers benefits over traditional forms of subtractive manufacturing such as Milling or Drilling due to its non-contact material removal mechanism which allows for hard materials and difficult cavity geometries such as sharp corners, thin features, or high aspect ratios to be machined easily. Despite these advantages, Electrical Discharge Machining suffers from low Material Removal Rates (MMR) and high-power consumption. The research presented introduces two innovative approaches to improve productivity in Sink EDM. The first of which is related to the enhancement of dielectric fluid flow (flushing) to aid in the evacuation of debris between the electrode and workpiece. This concept was found to improve machining conditions and increase MRR by as much as 2.45 times. The second topic relates to the use of simultaneous discharges to maximize the effectivity of using multiple tools when machining. The MRR for the tested “Series Multi-Tool” was found to be 1.74 times faster than conventional single tool machining, with promising potential of further MRR increases and greater energy efficiency by adding more tools in the future.