Researches On Behavior Of TiC_x Series Covalent Compound Binder And Different Category Diamonds In PCD

The properties of the binder and the grade of diamond powder are important factors affecting the properties of PCD.The traditional binder can not have both high toughness and high hardness.It is found by the former group that TiC_x powder can improve the toughness of sintered body and reduce sintering temperature,but make it brittle.On the basis,the metal Mo?addition volume of 5 vol.%-30 vol.%?is added to TiC_0.7 for improving the toughness of the binder,and compare the basic properties of different synthetic diamond powder and its performance under high pressure,with a view to the preparation of high performance PCD.In this paper,the effects of different milling time and sintering conditions on the high-pressure sintering of?TiMo?C_x powders were investigated.The results show that Mo can not completely enter into the TiC_0.7 lattice under the mechanical alloying.However,with the increase of the milling time,the diffraction peak intensity of Mo decreases,the lattice parameter of TiC_0.7 becomes larger,and Mo increases to TiC_0.7 lattice diffusion to deepen.When the addition of Mo is 10 vol.% the maximum hardness of the sintered body is 23.7 GPa appearing at 1400 ? under the high temperature and high pressure condition.When the Mo content is 25 vol.%,the sintered body attains the highest toughness that is 5.69 MPam1/2,and the sintered phase is?TiMo?C_x?X-ray diffraction?XRD?and energy dispersive spectrometer?EDS?were used to analyze the Primary diamond powder,impurities of the diamond powder prepared by the mechanical pulverization method and the sintered phase of the both.The structure and morphology of the diamond powder and sintered body were analyzed by field emission scanning electron microscopy?FESEM?.The oxidation resistance of diamond powder was analyzed by means of comprehensive thermal analysis?DSC-TG?.The results show that the primary diamond obtained by gravity separation has a certain amount of Si element on the surface,and the number of its inner catalyst inclusions is higher than that of the crushed diamond.The primary crystal of diamond is intact and the isosceles shape is the main one.The primary diamond with the same particle size has much higher oxidation resistance than crushed diamonds.For example,the starting oxidation temperature of the primary diamond is about 180 ? higher than the initial oxidation temperature of the crushed diamond.PCD was prepared by pulverized titanium primary diamond powder and titanium-plated crushed diamond powder,respectively.The former had low relative density and poor density.