Molten glass corrosion resistance of MoxRuySiz compounds at 1350 °C in an alkali borosilicate glass

Corrosion of Mo-silicides and Mo_xRu_ySi_z compounds in molten glass is studied by electrochemical techniques at 1350 °C, metallographic observations (SEM) and chemical analysis (EPMA). The open circuit potential measurements (free-potential) enabled the determination of the reactions responsible for the degradation of the materials.The degradation of Mo-silicide occurs through selective oxidation of Si. Mo_xRu_ySi_z compounds were subjected to reactions leading to the successive oxidation of silicon and molybdenum. The progressive depletion of Si and Mo resulted in the more or less quick formation of a thick, porous and low adherent Ru-layer. Therefore, Ru-additions had no positive effect on the molten glass corrosion resistance of MoSi₂-based materials and should even accelerate the degradation kinetics of the later through galvanic coupling.