Study On The Effect Of Synthesis Pressure On The Polycrystalline Diamond Compact

In the last century,the artificial diamond has went to a wide field of industrial applications from the laboratory with the rapid development of high temperature and high pressure technology,providing a solid impetus for the modern advanced manufacturing industry.One of the important inventions was the Polycrystalline Diamond Compact(PDC),which diamonds are sintered with Tungsten Carbide under high temperature and high pressure(HTHP).PDC has the characteristics of high wear resistance and high hardness,and the diamonds are isotropic,that makes the PDC have impact resistance,as well as the weldability and high toughness of the Tungsten Carbide.Therefore,PDC has been concerned and praised,and widely used in oil drilling,coal mining,geological research,grinding materials and cutting tools.The research and development of PDC has always been a hot field.Pressure and temperature are the key parameters for the synthesis of PDC.This paper focuses on the study of the performance differences of the PDC synthesized under different pressures.The method of synthesizing PDC is cobalt diffusion.Cobalt in the Tungsten Carbide substrate melts at high temperature,and then diffuses from the substrate to the whole diamond layer under high pressure,so the diamonds can bond to each other.In this experiment,6×36500KN cubic press was used,the temperature of synthesis was 1450?,and the heating time was 600 s.PDCs were synthesized under three different pressures of 6.72 GPa,6.97 GPa and 7.14 GPa,respectively.Before the synthesis experiment,the temperature and pressure of the synthesis were accurately measured.In this paper,when the pressure and temperature were measured,the assembly method was consistent with the actual assembly method of the sample synthesis,so as to ensure the accuracy of the experimental measurement.The wear ratio of the PDC synthesized under different pressures was tested,and it showed the effect of the synthetic pressure on the wear resistance.The density of the polycrystalline diamond layer can reflect the diffusion of Cobalt and Tungsten from the substrate to the diamond layer during synthesis.The samples were analyzed by SEM and EDX to judge the microscopic influence of different pressures on the PDC.The experiment clearly shows that although the pressure change is small,it has a great influence on the PDC.The higher the pressure is,the higher the density of the PDC is,and correspondingly the wear ratio of the PDC is also increased.