Diffusion-bonded tool electrode for electrical discharge machining with microchannels for jetting dielectric liquid

In this paper, we describe the improvement of the machining characteristics of sinking electrical discharge machining (EDM) using a tool electrode that has microholes for jetting dielectric liquid over the working surface. The tool electrode was made by diffusion bonding copper plates, on the surface of which microgrooves for jetting the dielectric fluid were formed by electrolyte jet machining. The bonded tool electrode was finished by turning to obtain a hemispherical shape. When dielectric liquid was dripped from the microholes over the tool electrode surface, processing time was shortened and machining stability and accuracy were improved compared with the case of the conventional solid tool electrode.