Microstructure of reaction-bonded silicon nitride prepared with Si3N4 additions

O. J. Gregory, Brown University
M. H. Richman, Brown University


The nitridation of silicon compacts containing small amounts of fully reacted silicon nitride powder was investigated. The enhanced microstructural control provided by these Si3N4 particles produced a reaction-bonded silicon nitride material with a greater density and fracture toughness. In particular, more effective control over the unreacted silicon and α β ratio in the nitrided compact was possible. Detailed microstructural examination of the resulting reaction-bonded silicon nitride provided further insight into the controlling reaction mechanisms and the role that these Si3N4 particles play in producing more fully reacted bodies with improved properties. © 1984.