A new type of sintered diamond reinforced by diamond MWCNTs composite fibers which were randomly orientated and even distributed in the diamond matrix was synthesized by using 3wt% mulhi-walled carbon nanotubes(MWCNTs) as starting additive under high pressure of 5.8 GPa at temperature of 1500 ℃ for 1 min. A special polycrystalline diamond structure of direct bonding of both diamond to diamond and diamond to diamond-MWCNTs composite fiber was observed. The testing results show that it possesses not only high hardness (49～52 GPa) and Youngs modulus (878 GPa) but also high bending strength (1320 ～ 1540 GPa)and fracture toughness (9.0 ～ 9. 2 MPa · m1/2) as it was theoretically predicted. The high performances of the composite were contributed by the fiber strengthening effect and the special structure which can offer more extensive diamond to diamond bonding.
mullti-walled carbon nanotubes (MWCNTs) nano-polycrystalline diamond fiber high pressure high temperature (HP-HT) properties
Deng Fuming Lu Xuejun Liu Ruiping Xu Guojun Chen Quwu Li Wenzhu
Department of Materials Science and Engineering, China;University of Mining and Technology, Beijing Department of Materials Science and Engineering, China;University of Mining and Technology, Beijing Department of Materials Science and Engineering, China;University of Mining and Technology, Beijing Beijing Institute of Electro-machining, Beijing, 100083, China Department of Materials Science and Engineering, China University of Mining and Technology, Beijing Department of Physics, Zhejiang University, Hangzhou, 310027, China