Micro electro-discharge machining and its applications

A micro electro-discharge machining (MEDM) technology is presented. It allows machining of micro holes and shafts as small as 5 mu m in diameter with a best surface roughness of 0.1 mu m R/sub max/ and of roundness of 0.5 mu m, as well as a variety of complex shapes of equivalent accuracy. In the MEDM, machining for silicon with 10-100 Omega -cm resistivity is possible; machining up to a depth of 10 times the electrode diameter is easy, and the electrode wear is small. A prototype microair turbine of 2.2 mm external diameter, which is able to rotate at a speed of approximately 1000 r.p.m., is discussed.<
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