Synthesis of ZrB 2 Powders from ZrO 2 , BN , and C

Submicrometer (200–800 nm) ZrB 2 powders have been successfully prepared via a new ZrO 2 –C– BN precursor powder system at a relatively low temperature (1550°C) for 1.5 h. As a moderate cost boron source, BN has a well‐defined stoichiometry and low impurity. Both thermodynamic and experimental results indicated that ZrC was formed below 1300°C, a temperature required for ZrB 2 formation. Moreover, the reaction of ZrC– BN mixture at 1300°C indicated that the ZrC acted as an effective direct reducing reagent for BN to form ZrB 2 , indicating that the pathway involving the formation of intermediate phase ZrC determined the formation mechanism.