Ultrahigh temperature Ceramics for Thermal Protection systems, Propulsion and Energy: From densification to thermo mechanical properties

Ultra high temperature ceramics (UHTC) include borides and carbides of early transition metals and are presently considered a class of promising materials for several applications, the most appealing ones being in the aerospace and energy sectors. Once densification problems are properly addressed, a crucial issue for application in severe environment is the improvement of fracture toughness and thermal shock resistance. To this purpose incorporation of SiC or C short fibers in UHTC matrices is adopted and effects on densification, microstructure and thermo-mechanical properties are studied. The present talk will show the latest developments in UHTC research at ISTEC, including processing and characterization aspects of composites containing different kinds of commercially available fibers. Transmission electron microscopy is used as a fundamental technique for microstructural characterization and for a deeper comprehension of densification mechanisms and microstructure/thermo-mechanical properties relationship.