Fabrication of Polycrystalline Diamond Wheels by Micro Wire-EDM using a Novel Pulse Generator

This paper presents the application of micro wire electrical discharge machining (micro wire-EDM) for profile roughing and final dressing of polycrystalline diamond (PCD) wheels using a specific pulse generator. The pulse generator using anti-electrolysis circuitry and digital signal processor based pulse control circuit was developed to suppress damages on the machined surface of PCD while achieving stable machining. In comparison with wire-EDM, micro wire-EDM could achieve better surface quality and smaller thickness of damaged layer for the fabrication of PCD wheels. A grinding-edge thickness of 3 m could be sharpened by micro wire-EDM compared with an edge-thickness of 6 m for wire-EDM. Experimental results have verified the applicability of micro wire-EDM for the fabrication of PCD wheels.