Investigation of wire electrical discharge machining of thin cross-sections and compliant mechanisms

The wire electrical discharge machining (EDM) of cross-section with minimum thickness and compliant mechanisms is studied. Effects of EDM process parameters, particularly the spark cycle time and spark on-time on thin cross-section cutting of Nd-Fe-B magnetic material, carbon bipolar plate, and titanium are investigated. An envelope of feasible wire EDM process parameters is generated for the commercially pure titanium. The application of such envelope to select suitable EDM process parameters for micro feature generation is demonstrated. Scanning electron microscopy (SEM) analysis of EDM surface, subsurface, and debris are presented. SEM observations lead to a hypothesis based on the thermal and electrostatic stress induced fracture to explain the limiting factor for wire EDM cutting of thin-sections. Applications of the thin cross-section EDM cutting for manufacture of compliant mechanisms are discussed.