In-situ formation of reinforcement phases in ultra high temperature ceramic composites

摘要

A tough ultra-high temperature ceramic (UHTC) composite comprises grains of UHTC matrix material, such as HfB₂, ZrB₂ or other metal boride, carbide, nitride, etc., surrounded by a uniform distribution of acicular high aspect ratio reinforcement ceramic rods or whiskers, such as of SiC, is formed from uniformly mixing a powder of the UHTC material and a pre-ceramic polymer selected to form the desired reinforcement species, then thermally consolidating the mixture by hot pressing. The acicular reinforcement rods may make up from 5 to 30 vol % of the resulting microstructure.