VAPORIZATION OF CUBIC CARBIDES OF VANADIUM, NIOBIUM, AND TANTALUM

A study is made of the vaporization of nonstoichiometric cubic carbides MC(Y) of vanadium, niobium, and tantalum in a vacuum within the temperature interval 2070-2670 K. It is established that an increase in temperature is accompanied by displacement of the composition of congruently vaporizing vanadium carbide toward the upper boundary of its homogeneous region and displacement of the compositions of the congruently vaporizing carbides of niobium and tantalum toward the lower boundary of the homogeneous regions of the corresponding cubic carbide phases. The rates of vaporization are determined and the partial pressures of the metals and the carbon above the investigated carbides are calculated.