Effect of sintering additives and reinforcement on microhardness values of Si3N4 Ceramics and Composites
Journal: Journal of Advanced Research in Mechanical Engineering
In this research study, microhardness value of silicon nitride ceramics and its composites have been obtained by using Vickers and Knoop indenters. Samples of six silicon nitride ceramics were used for this study. These are Si3N4 + Y2O3, Si3N4 + MgO, Si3N4 + TiC, Si3N4 +TiN, Si3N4 +BN and Nano- Si3N4 + Nano-BN. Samples of Silicon nitride ceramics ( Y2O3 and MgO) and its composites of TiC, TiN and BN were prepared by hot pressing. Nano-Si3N4 + Nano-BN ceramic composite was developed by Spark Plasma Sintering. Vickers and Knoop hardness values were obtained under high load of 0.05Kg to 2.0 Kg. Fracture toughness of Si3N4 ceramics and its composites was also obtained by Vickers micro-indentation method. Higher hardness and higher fracture toughness was observed in nano-Si3N4 + Nano -BN, as compared to other Si3N4 ceramics and its composites.