Investigation of the sintering behavior of SiC-5TiB2 composites reinforced by graphene quantum dots

The purpose of this research is to fabricate and investigate the properties of SiC-5TiB2 nano composites reinforced with graphene quantum dot nanoparticles by a pressureless sintering method. In this way, SiC, TiB2, and graphene quantum dots were used in nanometer dimensions. First, before performing any laboratory operation, the thermodynamic behavior of the system was checked using HSC software. The graphene quantum dots reinforcement amount was 0.6 wt%, and the sinter temperature was defined as 2000, 2050, 2100, 2150, and 2200 °C. After weighing the initial powders, the grinding process was carried out in an ethanol-based wet environmental and a polymer chamber, using zirconia balls, for two hours at a speed of 200 rpm. The sintering process was also carried out at certain temperatures in an argon atmosphere for two hours. Then, XRD, FESEM, and Raman analyses were performed, and density, microhardness, and fracture toughness tests were used for further investigations. The microstructure of the samples was also investigated to investigate the fracture toughness mechanisms. The results show that the sample sintered at 2150 °C with a relative density of 96.26%, and a hardness of 28.65 GPa and a fracture toughness of 4.1 MPa.m1/2 is the best case.