Volume 8, Issue 2 (February 2011)
Evaluation of Cutting Edges Made of Nanocrystalline Cemented Carbides Sintered by the Pulse Plasma Method
In our investigations, nanocrystalline WC-5 wt % Co was consolidated by the pulse plasma sintering method at various temperatures between 1320 and 1560 K under a pressure of 60 MPa for 300 s. The cemented carbides sintered at 1520 K have a relative density of 100 %, hardness of 2100 HV30, and tungsten carbides (WC) crystallite size of about 150–300 nm. An increase of the sintering temperature to 1560 K results in the increase of the WC crystallite size to about 300–500 nm and the hardness being decreased to 1980 HV30. The tool life of the cutting edges made of nanocrystalline cemented carbides sintered by the pulse plasma method is increased about two times in comparison with cutting edges made of standard and fine-grained cemented carbides during the turning of EN1.45.40 (1H18N9T) austenitic steel.