Interaction of scandium sesquioxide with carbon

In the range of 2350-2470 degrees K at a PCO = 0.0 MPa, interaction in Sc/sub 2/O/sub 3/ with carbon mixtures initially occurs by CO chemisorption at the scandium oxide surface and disproportionation into CO/sub 2/ and C, with subsequent replacement of oxygen in the oxide anion sublattice by carbon to form ScC. The carbide melt, creating a contact between the reagents, then transforms the process to a diffusion-based one. At 1820-2220 K in vacuum, reduction of the studied mixtures occurs by dissociative vaporization of the oxide, with precipitation of ScC at the carbon surface and generation of CO. The appearance of CO in the vapors of mixture leads to formation of an oxycarbide phase and to the partial occurrence of oxide dissociation.