Abstract

Ultra-High Temperature Ceramics are a family of compounds that display a unique set of properties, including extremely high melting temperatures (>3000A°C), high hardness and good chemical stability and strength at high temperatures. Structural materials for use in high-temperature oxidizing environments are presently limited mostly to SiC, Si3N4, oxide ceramics and composites of these materials. The maximum use temperatures of silicon-based ceramics is limited to ~1600A°C due to the onset of active oxidation (lower temperatures in water vapour environments), whilst oxides have exhibited high creep rates at higher temperatures. The development of structural materials for use in oxidizing and rapid heating environments at temperatures above 1600A°C is therefore of great engineering importance.