Synthesis of ZrB2 Powders from ZrO2, BN,and C

Submicrometer (200–800 nm) ZrB₂ powders have been successfully prepared via a new ZrO₂–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 ZrB₂ 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 ZrB₂, indicating that the pathway involving the formation of intermediate phase ZrC determined the formation mechanism.