Simulation of Flow Field and Experimental Study on the Electric Discharge Machining of Small Holes in Renewable Dielectrics

Vegetable oil is regarded as a medium that can replace kerosene in electrical discharge machining (EDM) hole processing due to its renewability and environmental friendliness. Meanwhile, numerical simulation serves as an effective means to study the behavior of the gap flow field during EDM processing. Based on this, this study explored the influence of hole size and different vegetable oil dielectrics (sunflower seed oil, canola oil, and soybean oil) on the movement of electro-corrosion residues in the processing gap. The simulation results demonstrate that the viscosity of the oil affects the escape rate of the particles. In holes of 1 mm and 4 mm of size, the escape rate of canola oil at any time period is superior to that of sunflower seed oil and soybean oil. In a 1 mm hole, its average escape rate reached 19.683%, which was 0.24% and 0.19% higher than that of sunflower seed oil and soybean oil, respectively. Subsequently, experiments were conducted in combination with the simulation results to explore the influence of current, pulse width, and pulse interval on hole processing. This further confirmed the application potential of vegetable oil in electrical discharge micro-hole processing and provided theoretical support and experimental basis for optimizing the green manufacturing process.