Experimental Investigation of Electric Discharge Machining of Nimonic C-263 Using Circular Shaped Copper Tool Electrode

This study focuses on Electric Discharge Machining (EDM) of Nimonic C-263, a nickel-based superalloy known for its high strength, corrosion resistance, and performance at elevated temperatures. The research emphasizes the use of a circular copper electrode to evaluate machining performance indicators such as Material Removal Rate (MRR) and Tool Wear Rate (TWR). Key EDM process variables—including discharge current, pulse on-time, and pulse off-time—were systematically varied to observe their impact. Results indicate that discharge current is the most influential parameter affecting MRR, followed by pulse on-time and pulse off-time. A Taguchi L9 orthogonal array was utilized to optimize process conditions. The best machining setup was determined to be a 10 A current, 7 µs pulse on-time, and 5 µs pulse off-time. These results offer practical guidance for efficient EDM of Nimonic C-263 and contribute to a deeper understanding of the machining mechanisms involved.