Investigation of the Influence of Tool Geometry in High-Pressure Wire Electrochemical Machining with Internal Radial Flushing on Process Stability and Productivity

Wire electrochemical machining (wire ECM) is a promising manufacturing process that combines the principle of anodic metal dissolution with the kinematic flexibility of a wire electrode. By using a wire instead of a task-specific tool, wire ECM enables the production of complex 2.5-dimensional contours without the costly and time-consuming tool design process. Process stability and productivity in wire ECM are strongly dependent on the effective flushing of the narrow working gap. A radial flushing method employs a perforated hollow wire electrode, allowing the electrolyte to be delivered directly into the machining zone. This approach improves removal of dissolved material and reduces the dependency of the flushing concept on workpiece thickness, unlike in axial flushing. Increasing the flushing pressure improves electrolyte exchange, which can enhance process stability and productivity. However, the influence of flushing pressures above 20 bar has not yet been sufficiently investigated for the radial flushing method. In this study, a high-pressure pump with operating pressures up to 100 bar is used to examine the role of flushing in wire ECM. Since the flushing regime is influenced by factors such as the internal diameter of the hollow wire electrode and perforation configuration, their effects on process stability, productivity, and surface quality in relation to workpiece thickness will be investigated.