Polycrystalline cubic boron nitride was sintered under high temperature(1400℃)and high pressure(5.5 GPa)using an in situ synthesis method.The composition,microstructure,relative density and mechanical properties of t...Polycrystalline cubic boron nitride was sintered under high temperature(1400℃)and high pressure(5.5 GPa)using an in situ synthesis method.The composition,microstructure,relative density and mechanical properties of the polycrystalline cubic boron nitride(PcBN)with different contents of Gd_(2)O_(3) were studied by means of X-ray diffraction(XRD),scanning electron microscopy(SEM)and energy-dispersive spectroscopy(EDS).The results show that the phases of TiB_(2),TiN,AIN,AlTi_(2)N and GdB_(6) are formed through in situ synthesis of cBN-Al-Ti-Gd_(2)O_(3) system.With the Gd_(2)O_(3) content increasing,the relative density increases and mechanical properties of PcBN begin to increase and then decrease.Proper amount of Gd_(2)O_(3) can advance the formation of TiB_(2) and improve the aspect ratio of TiB_(2).When Gd_(2)O_(3) content is 1.0 wt%,the PcBN exhibits optimal comprehensive mechanical properties,with a microhardness of 33.35 GPa and a flexural strength of 972.37 MPa.展开更多
基金financially supported by the Innovation-Driven Development Special Fund Project of Guangxi Province,China(No.AA17204020)the Open Research Project of Key Laboratory of Superhard Materials of Guangxi Province,China(No.2017-K-01)。
文摘Polycrystalline cubic boron nitride was sintered under high temperature(1400℃)and high pressure(5.5 GPa)using an in situ synthesis method.The composition,microstructure,relative density and mechanical properties of the polycrystalline cubic boron nitride(PcBN)with different contents of Gd_(2)O_(3) were studied by means of X-ray diffraction(XRD),scanning electron microscopy(SEM)and energy-dispersive spectroscopy(EDS).The results show that the phases of TiB_(2),TiN,AIN,AlTi_(2)N and GdB_(6) are formed through in situ synthesis of cBN-Al-Ti-Gd_(2)O_(3) system.With the Gd_(2)O_(3) content increasing,the relative density increases and mechanical properties of PcBN begin to increase and then decrease.Proper amount of Gd_(2)O_(3) can advance the formation of TiB_(2) and improve the aspect ratio of TiB_(2).When Gd_(2)O_(3) content is 1.0 wt%,the PcBN exhibits optimal comprehensive mechanical properties,with a microhardness of 33.35 GPa and a flexural strength of 972.37 MPa.
