Chapters authored
Preparation of Ultra-High Temperature Ceramics–Based Materials by Sol-Gel Routes
Ultra‐high temperature ceramics (UHTCs) are a class of inorganic materials that have melting point over 3000°C and are typically borides, carbides, and nitrides of early transition metals. UHTCs are considered as the promising candidate used in the extreme environment involved with the hypersonic aviation thermal protective system. Synthesis of UHTC‐based materials can be divided into solid‐based and solution‐based protocols according to the state of the raw materials. A sol‐gel technique is one of the solution‐based protocols for the preparation of UHTC‐based materials, which involves the hydrolysis, condensation of the metal organic and/or metal inorganic compounds, gelation, and the posthigh temperature treatment of the dried gels. The sol‐gel technique enables the synthesis of UHTC‐based materials at 1300–1600°C. UHTC‐based materials with desired shapes, such as nanopowders, fibers, and porous monoliths, can also be prepared via sol‐gel routes.
Part of the book: Recent Applications in Sol-Gel Synthesis