Study on Micro-EDM (3rd Report)
Fabrication of Micro-mechanical Elements
1994 Volume 28 Issue 59 Pages 1-10
Details
1994 Volume 28 Issue 59 Pages 1-10
Several important features of micro-EDM were tested and the feasibility to the parts production for micromachines was confirmed through the fabrication of practical micro components.
Main results are as follows.
It was clarified that silicon wafers which have the resistivity range of 0.02 to 50ohm-cm are machinable by micro-EDM. Machining time and electrode wear are less than those in the case of metals. The reason is assumed to be that the machining mechanism mainly involves the generation of microcracks and fracture rather than melting.
Through the analysis of electrode wear, a process sequence was found to be preferable for machining complex shapes. That is:1. The rough shape is machined by the axial movement of the electrode repeated along the contour. 2. The side wall is finished by a continuous movement of the electrode along the surface.
A micro-air turbine with 2.2mm diameter and a micro-polygon mirror with 2mm side length are successfully manufactured with the developed micro-electrodischarge machine and the shaft-making machine using the principle of wire electrodischarge grinding (WEDG).
