Oxidation–reduction processes upon interaction of aluminum oxide melt with molybdenum and tungsten in a hydrogen-containing atmosphere

Abstract

A thermodynamic analysis of the processes occurring in the Мо–W–Al₂O₃ system at T = 2400 K and a total pressure of 1 bar, set by controlled reducing Ar + H₂ atmosphere, has been performed. It is found that the basic components of the system do not interact directly, although may be actively involved in chemical reactions with participation of other components to undergo numerous cyclic oxidation–reduction processes. Particular attention is paid to the processes involving such chemically active reagents as Н₂O₂, HO₂, H₂ (H), gaseous Al, and its hydrides (AlH, AlH₂, AlH₃).