Abstract
The preparation of ZrC powder from ZrO2 by reduction with Mg has been investigated from 500° to 1000°C for 2 to 5 molar ratio of Mg/ZrO2 under a flow of methane. ZrC was formed above 650°C. The reaction finished within 30min above 750°C.
The ZrC powder obtained at 1000°C was ultrafine (below 0.1μm) and had a C/Zr ratio of 0.96. The contents of 0 and Mg in the ZrC powder were 2.9 and 0.4wt%, respectively. The content of free carbon in the ZrC powder became 0.4wt% by decreasing the concentration of CH4 to 40%. The apparent activation energy for the formation of ZrC was approximately 83.3KJ/mol (750°-900°C).
