Ultra - High Temperature and -Hard Materials

Principal investigator: F. Inam
Co-investigator(s): B. Milsom and Mike REECE

Carbides, nitrides and borides ceramics are of interest for many applications because of their high melting temperatures, good mechanical properties, including high hardness, and low density. For example the material with the highest known melting temperature is the carbide Ta4HfC5 at 4215 °C. While boron dicarbonitride (BC2N) is classed as the fourth hardness material known to man, with the commercially used boron nitride (B4C) sixth. These materials require high temperatures and pressures to densify them. Even under these conditions they may not fully densify. Nanoforce is investigating the potential of SPS to densify these materials to close to theoretical density. Nanoforce is working with Dstl and the Centre for Advanced Structural Ceramics (CASC) at Imperial College London to develop the next generation of ultrahigh temperature ceramics based on the diborides of zirconium and hafnium (ZrB2, HfB2). These may find application in the leading edges of hypersonic vehicles (fig. 6), where they may need to operate at temperatures above 2000 °C while maintaining structural integrity.