Synthesis and Performance of Hf- based Ceramics

Abstract

HfC and HfB2 are known to be important ceramics for high-temperature applications due to their high thermal stabilities and oxidation resistance. HfC/HfB2 ceramic composite along with monolithic HfC was prepared from corresponding oxides in the form of nano powders by high-energy milling and boro/carbothermal process. The powders were consolidated by Spark Plasma Sintering method. Uniform microstructures were obtained with high densities, which are attributed to in-situ formation of carbide and boride particles from oxides. The uniformity in microstructure and properties is notable advantage of this in-situ process. In this paper the systems will be compared and discussed in terms of thermal stability and high-temperature performance.