Processing and properties of pressureless-sintered Si3N4-SiC composites

Silicon nitride (Si3N4) ceramics are potential candidates for structural application where their high temperature strength and resistance to oxidation and corrosion properties can be utilized. Despite these good properties, the brittle nature of silicon nitride ceramics limits their applications. Reinforcement of ceramics by second phases (whiskers, platelets, fibres, powders) can improve their fracture toughness by the mechanisms related to fibre sliding, crack deflection, crack boving and micro-crack formation.