Chemical reactions in the Mo-W-Al2O3 system at 2400 K and 100 Pa

We examine the behavior of the Mo-W-Al₂O₃ system at T = 2400 K and p = 100 Pa and identify the main chemical reactions that lead to the oxidation of Mo and W. The results indicate that, under these thermodynamic conditions, direct reaction between Mo, W, and molten Al₂O₃ is impossible, and oxidation processes are indirect and involve vapor species. For a Mo: W: Al₂O₃ molar ratio of 1: 1: 1, we calculate the gas-phase composition and demonstrate that the predominant vapor species are Al, AlO, Al₂O, MoO, MoO₂, and WO₃.