Study on sequential machining of EDM and grinding for the end face of cemented carbide round bar using EC-PCD tool

摘要

A sequential machining method of EDM (Electro discharge machining) and grinding has been proposed by rotating a PCD (polycrystalline diamond) segment made of conductive diamond particles for machining cemented carbide materials. In this study, in order to achieve the on-machine forming of the end face of a cemented carbide round bar material used as a cutting tool for rotary cutting with a 5-axis multi-tasking lathe, sequential machining experiments are performed by rotating the cemented carbide round bar without rotating the PCD tool. First, in basic experiments using Die-sinking EDM machine, the end face of a rotating cemented carbide round bar is EDMed using a fixed arc PCD as an electrode, and then the rotating cemented carbide round bar is pressed against the PCD surface. As results, it is clarified that the heat-affected layer due to electric discharge remaining on the cemented carbide surface is removed by grinding action using PCD. In addition, it is shown that when an electro discharge function is installed in 5-axis cutting machine, on-machine forming of a cemented carbide round bar tool in the cutting machine is possible.