Abstract
This paper deals with machining methods of fine graphite electrode for EDM by Q-switched Nd: YAG laser. Graphite is a superior material as an electrode for EDM and has widely been used. However, it is difficult to make a complicated shape of thin graphite plate less than 1mm by the conventional machining methods because of its brittleness. In this paper, Q-switched Nd: YAG laser is used for machining the micro rectangular parallelepiped graphite electrode whose thickness is 0.35mm.
Main conclusions obtain are as follows:
1. The rectangular parallelepiped whose sections is about 0.35mm square can be machined precisely by Q-switched YAG laser.
2. Cutting off method of 2 plates of workpieces together leads to a better rectangular parallelepiped shape of the lower plate.
3. The roughness of machined surface is improved by another scanning with lower power laser.
4. In normal polarity EDM with RC circuit in deionized water, a better rectangular hole can be generated with copper impregnated graphite electrode.
