چكيده به لاتين
In this study, cemented carbides (94 - x) wt% WC - xwt% TiC - 6wt% Co were fabricated using Spark plasma sintering at three temperatures of 1200℃, 1300 ℃ and 1400℃ for 5 and 10 minutes. Initially, the primary powders were investigated using scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) and dynamic light scattering(PSA-DLS) and Then, the effect of titanium carbide nanoparticles and sintering temperature were evaluated on the microstructure, hardness, density and fracture surface of this type of hardmetals. The results show that the addition of titanium carbide nanoparticles from 1 to 3 wt% can decrease the average grain size of tungsten mono carbide. At temperatures of 1300℃ and 1400℃ for samples with no titanium carbide nanoparticles The average tungsten carbide grain size was obtained 0.95μm and 1.0μm, respectively By adding titanium carbide nanoparticles, this number decreased to 0.38μm and 0.75μm, respectively. Phase analysis results show that the addition of titanium carbide causes the addition of tungsten monocarbide (WC), cobalt (Co) and titanium carbide (TiC) phases, and other new phases in this type of cemented carbide One of the most important of these phases is the solid solution created by dissolution of tungsten carbide particles in titanium carbide.With the addition of titanium carbide nanoparticles the hardness increased from 1679/985 HV to 2280/37 HV in this type of hardmetals This is due to the formation of a solid solution of titanium tungsten carbide( Ti3/3W6/7C7) between tungsten carbide and titanium carbide, with a much higher hardness than any of the tungsten carbide and titanium carbide phases as well as inhibiting the abnormal growth of tungsten carbide.The density results show that by increasing the titanium carbide content, the density values from 14.99 g/cm3 to 14.23 g/cm3 for the sintered samples at 1300℃ and from 14.81 g/cm3 to 14.20 g/cm3 for sintered samples at 1400℃ is reduced.Investigating the fracture surface of samples with different percentages of titanium carbide also shows that the fracture surface of these materials is a brittle fracture, but it is clearly seen that the percentage of fractures of the type intergranular fracture is far more than the percentage of transgranular fracture.
