Transmission electron microscopy of interfaces in structural ceramic composites

Ceramic composites based either on a particulate, fibre or a lamellar archi tecture are potentially useful as damage-tolerant high-temperature engineer ing materials. The ability of the interfaces in such systems to deflect cra cks is vital to the damage tolerance of these materials. Transmission elect ron microscopy techniques enable the chemical and physical characterization of these interfaces, providing information on interlayer thicknesses, chem ical species, local bonding and the microstructural features which give ris e to the interfacial properties, thereby enabling a full understanding not only of composites after processing, but also after exposure to aggressive environments such as air at high temperature. Examples of the application o f transmission electron microscopy to all three composite architectures are described.