Micro EDM (Electro Discharge Machining) is a known nonconventional process for the machining of hard to cut materials.
Due to its ablating nature based on melting and evaporation through heat induced by electrical discharges, it can function independently of the hardness, toughness or brittleness of the workpiece.
Because of these benefits, EDM is widely used in tool- and mould making; micro-EDM, with its much lower discharge energies, has been successfully applied to micromachining of high-accuracy parts.
The precision manufacturing of high aspect ratio micro geometries such as deep micro bores relies on stable process conditions in the discharge gap.
Its minimization – a precondition for minimal feature size and higher accuracy – limits the effectiveness of conventional flushing techniques, leading to a higher fraction of unwanted discharge states (open and short circuit), lower process speed, and geometrical errors. New hybrid technology approaches, such as ultrasonic or low frequency superposition, significantly raise the process stability and speed.