Accelerated precision manufacturing through electro discharge machining with ultrasonic vibration assistance

Electro Discharge Machining (EDM) is an established process in the die- and toolmaking sector. Since it is independent of material hardness, brittleness or toughness and can use easy to machine tool electrode material, it is especially suitable for micro machining [1]. It is widely used in the production of nozzles such as applied in high-pressure diesel common rail or gasoline injection systems. Typical other applications are spinnerets or micro cavities in injection moulding tools. However, for deep and high-aspect-ratio bores, the insufficient flushing is limiting performance and precision. Especially for bore diameters of less than 150µm the machining speed is dramatically reduced [2]. The application of ultrasonic vibration to the workpiece was investigated and proven to affect the micro-EDM process in a very positive way. Not only a major stabilisation, but also a speed enhancement of up to 50% compared to an optimised conventional process could be achieved.