Si3N4/BN fibrous monoliths: Mechanical properties and tribological responses

Ceramic fibrous monoliths (FMs) consist of fiber-like cells that surround a weaker matrix phase called the cell boundary. FMs based on Si3N4/BN exhibit many excellent mechanical properties, and much work has been done to characterize and understand the relations among their processing, microstructure, and properties. The following body of data and understanding for Si3N4/BN FMs are discussed in this paper: processing, elastic constants, in-plane fracture and modeling of fracture, thermal stresses, interfacial shear strength and tailoring of gross interface structure, creep, impact erosion resistance, and sliding wear resistance. Possibilities to improve their properties are also presented.