Micro-electrical discharge machining

Micro electrical discharge machining (EDM) is primarily used for hard metals and other electrically conductive materials. When two electrodes separated by a dielectric medium come close, the dielectrical medium breaks down and suddenly becomes conductive. Sparks generated between the electrodes release energy and remove metal by melting and evaporation [30], Murali and Yeo combined micro electro-discharge machining with ultrasound electrode vibration for improved surface quality, and achieved micro features as small as 25 pm on titanium with 20 pm diameter electrodes [30]. 

The die for the rubber forming process was manufactured by micro electrical discharge machining on a stainless steel plate of 25xl0xl.5mm. The microgrooves on the die were about 0100 (xm as shown in Figure 1. 

Uhlmann E, Piltz S, Doll U (2005) Machining of micro/miniature dies and moulds by electrical discharge machining - recent development. J Mater Process Technol 167 488-493... 

Two different sized features are examined in this study (1) parts molded from micro-featured dimensioned surfaces with dimensions ranging in a few hundred microns molded on Stainless Steel grade 304 by Wire Electric Discharge Machining (EDM), and (2) nano-featured parts with dimension ranging up to a few hundred nanometers formed on silicon (Si) wafers through Deep Reactive Ion Etching (DRIE). 

---