Cutting-edge surface generation on super Co 605 high entropy alloy using EDM process approach

• HEAs like Super Co 605 excel in aerospace for thermal stability & fracture toughness. • EDM evaluates MRR, MH, SR & TWR on Super Co 605 using copper & graphite tools. • Graphite electrodes (negative polarity) give 96.79% MRR & 41.53% MH boost over copper. • Copper electrodes offer better surface finish & tool life than graphite. • Graphite tools increase MH & self-lubrication via carbon deposition, enhancing HEA use. High-entropy alloys (HEAs) are a unique class of materials developed over the past two decades. These alloys leverage optimized entropy to achieve low free energy, offering exceptional properties such as high thermal stability and superior fracture toughness. Among these, cobalt-based HEAs are particularly promising for applications in aerospace, warranting further exploration of their machining characteristics. This study focuses on the surface generation of the Super Co 605 high-entropy alloy using the electric discharge machining (EDM) technique. Three trials experiments were conducted under varying conditions, evaluating material removal rate (MRR), micro-hardness (MH), surface roughness (SR), and tool wear rate (TWR) using copper and graphite electrodes. The results reveal that for maximum MRR and MH, a negative tool polarity with a graphite electrode yields the best performance compared to copper electrodes. Conversely, superior surface finish and minimal tool erosion are achieved with a copper electrode of negative polarity. The increased carbon content on the machined surface with the graphite electrode enhances micro-hardness and provides self-lubricating properties. Scanning electron microscope (SEM) analysis confirms improved surface quality with the copper electrode compared to the graphite electrode. These findings demonstrate the potential of cobalt-based HEAs for innovative applications in advanced engineering, particularly in aerospace technologies.