The Effect of Al on Phase Stability and Oxidation Behavior in Ternary Nb-Ti-Si Alloys

Abstract

In this paper, we report a significant improvement in mechanical and oxidation properties of near eutectic Nb–Si alloys by the addition of aluminum (Al) and control of microstructural length scale. Thus in order to develop new alloys, we have to choose proper alloying elements keeping all the above issues in mind. Among the non-transition elements such as Al, Ga, Ge, Sn, and Al is most attractive from the point of view of enhancing the oxidation resistance and room temperature ductility due to substitution of Si with metallic Al . Al forms oxides which are even more thermodynamically stable than Si and Nb based oxides. Al is also soluble in Nb to a greater degree in conjunction with other refractory elementsFig.1 The figure shows composite X-ray diffraction patterns of each sample exposed to air for one hour in a TGA furnace at above mention temperatures.