A STUDY ON THE PERFORMANCE OF COPPER-GRAPHITE AS TOOL MATERIAL IN MICROMACHINING BY MICRO ELECTRO DISCHARGE MACHINING

摘要

Experiments were carried out to asses the performance of copper-graphite as tool electrode in Micro EDM. Comparison of the results suggests that the productivity can be improved when copper-graphite is used as tool electrode. The machined surface is also smoother than that achieved with tungsten electrode. Hence copper-graphite can be used as tool electrode in applications such as through hole drilling. On the other hand, the tool wear and the spark gap are much lower when tungsten is used. Hence it is preferable to use tungsten as tool electrode for applications such as three-dimensional sculpture machining and micro mould machining where profile accuracy is important. Theoretical prediction . and SEM image show that the typical crater size in the machined surface using copper-graphite electrode is smaller than that obtained with tungsten electrode.