Abstract
A mold material is required strength, machinability, lightness, and corrosion resistance. However, both is difficult for single material. Therefore, a surface treatment technology is demanded. In the EDM, the tool electrode material is adhered to the workpiece. In the case of the using a tungsten tool electrode, it is possible that high hardness machined surface. In this study, in order to obtain high hardness EDMed surface, the effect of discharge current and tungsten powder grain size on the Vickers hardness was investigated. Spark plasma sintered compact was used as the tool electrode. The hardness of the EDMed surface was increased with an increase in discharge current. The coated layer of the EDMed surface was contained by tungsten. The coated layer thickness of the EDMed surface was increased with an increase in discharge current. In the case of the large tungsten powder grain size, the EDMed surface was indicated high hardness.
