Hot pressing of SiC additivated with Al2O3 and Y2O3

This work investigated the sintering of silicon carbide (SiC) with alumina (Al2O3) and yttria (Y2O3) additives by hot pressing. Mixtures of SiC with 1% and 5% Al2O3 and Y2O3 were used, pressed at 1800 °C and 1850 °C, resulting in specimens that were characterized in terms of density, microstructure, Vickers hardness and fracture toughness. The addition of 5% oxide additives provided greater densification and better mechanical properties. The temperature of 1800 °C proved to be the most effective for sintering due to the microstructure presented. The analysis revealed a homogeneous distribution of additives and grains, concluding that the 5% additive is considerably superior for increasing the densification and mechanical strength of SiC.