Development of micro-EDM-center with rapidly sharpened electrode

In single discharge machining of a 0.1 mm tungsten electrode with 30–50 A discharge current and several hundreds of microseconds duration, a needle of 20–40 μm in diameter has been formed instantaneously. The formed needle or thin axis’ tip radius is less than 100 nm. This new phenomenon is applied to making very thin electrodes for micro-EDM or as micro-probes for various on-the-machine measurements. Using a rapidly formed thin axis, micro-drilling was performed on-the-machine. Using the electrical discharge machine, the workpiece’s shape was measured in error of ±2 μm. Micro-EDM-machining-center with rapidly sharpened electrode was developed in order to implement precision micro-machining. With the proposed machining system, formation of micro-tool electrodes, micro-EDM and measurement of workpieces with sharpened probe can be carried out on the same machine.