High-Temperature Oxidation of Eutectic Alloy Nb-Si, Doped with Yttrium
Nb-Si composites with a high melting point and low density are of interest as a candidate material for use in aircraft engines. However, one major limitation in the application of composites Nb-Si is their poor corrosion resistance at elevated temperatures. The corrosion resistance of Nb-Si composites can be improved by alloying elements such as yttrium. This paper studied the effect of yttrium on the oxidation of eutectic alloy Nb-Si at 25-1000o in air by thermogravimetric method, X-ray diffraction analysis and electron-probe microanalysis. The oxidation products are the oxides of silicon and niobium, which are fixed at a temperature above 600oC. The positive effects of yttrium on the corrosion resistance of Nb-Si eutectic alloy up to 700oC shown. The content in the samples of more than 3%Y increases the oxidation rate of alloys and reduces their heat resistance at heated in air.