High Entropy Alloy machining by EDM and ECM

The thermal, mechanical and chemical stability of a material can theoretically be estimated by the Gibbs free energy of formation. Based on this, a new class of alloys - High Entropy Alloys (HEAs) - was designed in the past two decades, maximizing the entropy for a minimum free energy and consequently outstanding material properties. However, the machinability by conventional cutting is limited due to the increased stability. Therefore, electrical discharge machining (EDM) as well as electrochemical machining (ECM) are investigated as alternatives. This includes the fundamental analysis of surface morphology as well as resulting subsurface properties for two state-of-the-art second generation HEAs.