1. College of Mechanical Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
2. Shaanxi Taihe Intelligent Drilling Co., Ltd., Xi’an 712000, China
et al.
The performance of polycrystalline diamond composite sheet (PDC) is closely related to the diamond particle size, the dispersion uniformity of diamond particles and the distribution state of Co binder among diamond particles. PDC with diamond particle size of 3, 10, 16 and 25 μm were prepared by sintering at high temperature and high pressure. The phase composition, microstructure, thermal stability, friction coefficient and impact toughness of PDC with different diamond particle size were studied by X-ray diffractometer, scanning electron microscope, synchronous thermal analyzer, high-speed friction and wear test and impact resistance test. The results show that the strongest diffraction peaks of PDC prepared with different particle sizes are (111), (220), and (311). Moreover, the Co3O4 phase is found in the PDC with a diamond particle size of 25 μm. The Co binder of PDC with diamond particle sizes of 3, 10, 16 and 25 μm are distributed in the forms of fine particles, spherical and isolated shapes, vein-like and isolated shapes, and vein-like shapes, respectively. The PDC with a diamond particle size of 25 μm has the smallest friction coefficient, which is 0.049. The performance test results show that the PDC with particle size of 10 μm has the best performance, the wear ratio reaches 2.04×106, the impact toughness is 400 J, and the heat resistance temperature reaches 744 ℃.