Mechanical properties of cubic BC2N, a new superhard phase

A new superhard phase, cubic BC2N, has very recently been synthesized by direct conversion of graphite-like BN-C solid solutions at 25 GPa and 2100 K. The hardness. Young's modulus, fracture toughness and structure of this phase have been examined using micro- and nanoindentation and transmission electron microscopy. The hardness and elastic modulus values (E, G) of the c-BC2N are intermediate between diamond and cubic boron nitride. which makes this new phase the hardest known solid after diamond. (C) 2001 Elsevier Science B.V. All rights reserved.