Study on EDM Technics of Polycrystalline Cubic Boron Nitride Cutting Tool and PcBN Cutting Tool's Life

摘要

The samples of Polycrystalline cubic boron nitride (PcBN) cutting tool were machined by adjusting the main parameters of electrical discharge machining (EDM). After the machining, the phases were analyzed by X-ray diffraction analyzer and the surface layer microstructure was observed by scanning electronic microscope. The fundamental component of machined PcBN cutting tool affected layer was obtained and the reason of begetting affected layer was analyzed. The relationship curves between pulse width, working electric current and thickness of affected layer, blade surface roughness were summarized. The relationship between PcBN cutting tool's life that was machined by EDM and cutting tool flank width, workpiece surface roughness were analyzed. The results showed that to adjust electrical discharge machining parameters, such as decreasing pulse width or machining electric currents, can reduce the thickness of affect layer, improve blade surface roughness and extend the service life of PcBN cutting tool. These researches provide valuable test reference for drawing up electrical discharge machining technics of PcBN cutting tool and forecasting cutting tool's life.