Oxidation behavior of ZrB2 composites doped with various transition metal silicides

• Oxidation of ZrB2–MeSi2 (Me = Zr, Mo, Ta, W) at 1200–1800 °C.
• WSi2 and ZrSi2 have similar influence on the oxidation behavior of ZrB2 up to 1650 °C.
• TaSi2 could be adequately used up to 1500 °C, but above it is not suitable for ZrB2.
• MoSi2 was the best additive of ZrB2, due the formation of a stable subsurface layer.

This paper deals with the oxidation behavior of ZrB2-based composites sintered with different additives, namely ZrSi2, MoSi2, TaSi2 and WSi2. The oxidation mechanisms were investigated between 1200 and 1800 °C for 15 min in a bottom loading furnace. The scope of this study is to draw a classification of goodness for the 4 composites depending on the temperature range and understand how each cation influences the oxidation behavior of ZrB2 by acting either on glass or on ZrO2 modification. MoSi2 was the best additive for improving the oxidation resistance of ZrB2, even up to 1800 °C.

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