In this paper, some results on surface machining by EDM are treated in which several kinds of powder are suspended in working fluid.
The attainment of fine surface on large area with electrically conductive electrode such as copper is difficult because of its gap electrostatic capacity between electrode and work surface. Silicon electrode method was derived to break through these difficulties. But it is difficult to shape the raw material as a complex formed electrode in this silicon electrode method.
Several kinds of powder including silicon powder were suspended to dielectric fluid for use of work oil. We have got very fine and uniform surface of 1-2μm Rmax on the work of 100cm2 with copper or graphite electrode.
The dispersion of discharge current was confirmed widely throughout the whole area of electrode owing to powder suspension.
EDM by conductive electrode with powders in working oil is very practical in industry.
