Abstract
Vaporization of several refractory metal-Al2O3systems have been investigated by mass spectrometry in order to assess compatibility of these systems in elevated temperature. Nearly neutral conditions are reached in both tungsten-and molybdenum- Al2O3system. In these systems, vapor species and their partial pressures have been in good agreement with previous works. While, some reactions have been observed in both tantalum-and niobium-Al2O3systems. The main components of the gaseous phase in these systems were Al, and some metal oxide molecules. The partial pressures of them were nearly one order higher than in tungsten-Al2O3system. The compatibility of these reducible refractory metals have been discussed relating with their oxigen solubility, free energy of formation of oxides and production of oxide solution.
