A review of advances in electrical discharge machining: From flow field to multi-physics coupled simulations

• Comprehensive review of EDM flow field simulation and core model equations. • Analysis of the impact of various electrode structures on debris removal and efficiency. • Discussion on the coupled effects of multi-physics fields including heat flow and electric current. • Summary of the development and future research trends in EDM flow field simulation. Electrical Discharge Machining (EDM) is a vital non-contact machining technology for processing high-hardness, high-strength conductive materials. However, the accumulation of erosion debris and bubbles in the machining gap significantly weakens dielectric strength, affecting discharge stability and machining quality. Flow field simulation, a critical tool for analyzing the movement of dielectric fluids, debris, and bubbles in EDM, has gained significant attention in academia. This paper comprehensively reviews advancements in flow field simulation for EDM, outlining the equations of fluid models and mathematical models of erosion debris. The application of these models in specific processes, such as EDM drilling, wire EDM (WEDM), and EDM milling, is analyzed, highlighting how flow field simulations reveal debris removal mechanisms under various conditions. It specifically investigates the impact of electrode structure design, ultrasonic vibration, and magnetic field assistance on enhancing dielectric flow and debris removal efficiency. Additionally, the paper emphasizes coupled simulation studies integrating flow fields with thermal, electric, and plasma fields, clarifying their effects on material removal, surface quality, and machining precision, thus offering a thorough understanding of EDM’s intricate physical mechanisms. By synthesizing recent progress in flow field modeling and multi-physics coupling, this study provides a comprehensive approach to enhancing machining stability, accuracy, and efficiency, distinguishing itself from earlier studies that focused narrowly on singular aspects. Finally, it evaluates the current limitations of flow field simulation and suggests future research directions, such as refining multi-physics models, investigating nanoscale phenomena, and leveraging artificial intelligence for smart process optimization.