High Temperature And High Pressure Sintering Of TiCx-VC Based PCD Binder

Ti and Ti C were used as original materials, and nonstoichiometric compound Ti CX（x = 0.4, 0.5, 0.6） were synthesized by mechanical alloying（MA）, and then mixed with VC at different proportional ratio. The samples were prepared by high temperature and high pressure technology. The effects of sintering parameters, such as sintering temperature, pressure, soaking time, on the structure and properties of samples were discussed. The effect of different C content of nonstoichmetric compound Ti Cx on the properties of samples was also discussed.Firstly, Ti C₀.4-VC couple samples was prepared for diffusion behavior survey through energy dispersive spectrometer; The elements distribution near the interface area were analyzed and the phenomenon of C atom in VC transformed into Ti C0.4 vacancy was checked. Secondly, the sintering of mixture of Ti C0.4 and VC powders were subjected by the high temperature and high pressure. The Vickers hardness and fracture toughness of the sintered samples were measured by SEM observation of fracture morphology analysis of the sintered samples, the best ratio of VC is 30% volume fraction of mixture, the sintering temperature is 1500 ℃, which corresponds to a Vickers hardness of 22.5GPa, fracture toughness value of 3.69 MPa.m1/2. At the sintering temperature of 1600 ℃, the samples were over sintered. Thirdly, the effects of Ti Cx with different C contents, soaking time and sintering temperature on the structure and properties of Ti Cx/VC samples were discussed. The sintering temperatures were set as 1450 ℃, 1500 ℃, 1550 ℃, the value of x were 0.4, 0.5, and 0.6, the sintering holding time were 5min, 10 min, 15 min, respectively, The microstructure and phase composition of sintered samples were investigated by SEM and XRD. The Vickers hardness and fracture toughness of samples were also tested. The results showed that the Vickers hardness and fracture toughness of Ti C0.5/VC and Ti C0.6/VC were 21.13 GPa and 22.24 GPa, 3.87 MPa m1/2 and 3.73 MPa m1/2, respectively. The soaking time needed to sinter samples was shorten as the x value increased.