END MILLS WITH PCD INSERTS SHARPENED BY DIFFERENT ELECTRICAL TECHNOLOGIES

Initially a natural diamond was used for cutting, but it was successively replaced by an man-made - synthetic diamond. Its application is limited only on non-ferrous materials, but also considering this limitation it is a very important cutting material. The most suited material based on diamond for milling operations is PCD - a synthetic polycrystalline diamond produced by HPHT (high-pressure high temperature) process, because the high fracture toughness of the tool is required [DAVIS 1995] [Tso 2002]. Four end mills with PCD inserts sharpened by different electrical technologies were produced for the experiment as stated in this article. Two milling tools were sharpened by WEDM and the remaining two by Electrical Discharge Machining Grinding. The aim of the experiment was to compare these technologies of sharpening. This was based on the surface roughness and topography analysis of sharpened surfaces of inserts, and in particular, on the force loading of the tools measured by the piezoelectric dynamometer 9257B over selected milling time slots.