Enhancing mechanical properties of hydroxyapatite-reduced graphene oxide nanocomposites by increasing the spark plasma sintering temperature

In this study, the reduced graphene oxide (rGO)-Hydroxyapatite (HA) powders were first synthesized by a hydrothermal method. The amount of graphene in these powders was 1.5% by weight. Subsequently, these powders were consolidated at 900, 930, and 950 degrees C by spark plasma sintering (SPS) method, while the pressure applied in the process was 50 MPa. The sintered samples were characterized by X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and Vickers indentation methods. The results of this study showed that increasing the sintering temperature increased the relative density of the samples. Mechanical properties such as elastic modulus and hardness increased with increasing sintering temperature. The results of the microscopic analysis confirmed the presence of rGO sheets in the final nanocomposites. According to the findings of this study, considering the applied conditions, the best temperature for sintering was 950 degrees C.