Coated Electrode Performance in µEDM of Alloy Steel: A Parametric Optimization Study

Micro-Electrical Discharge Machining (µEDM) precisely creates micron-scale holes, vital for components like fuel injectors and nozzles. The process relies on controlled electrical discharges between the tool (typically the cathode) and the workpiece (anode). High-temperature (up to 10,000 Kelvin) pulses generated by the µEDM process melt and vaporize the workpiece This research work investigates the impact of various parameters on µEDM, including input current, pulse duration (on and off times), aiming to optimize these for a specific tool-workpiece combination (brass tool and a carburized alloy steel workpiece) to achieve the highest Material Erosion Rate (MERT) while minimizing Tool Erosion Rate (TERT). Experiments explored the effects of three parameters – current, pulse-on time, and pulse-off time on both MERT and TERT. Furthermore, the investigation explores the impact of a TIN coating on the tool's wear behavior during micro hole fabrication. The comparative optimization study revealed a significant 70% reduction in tool wear.