Microstructure, mechanical properties and oxidation behavior of Nb–Si–Al and Nb–Si–N powder compacts prepared by spark plasma sintering

First tentative Nb–Si–Al and Nb–Si–N ternary phase diagrams were constructed by investigating microstructures of spark plasma sintered compacts of these systems. The microstructure, mechanical properties and oxidation behavior of compacts with some different compositions in the two systems were then examined. Nb3Si5Al2 matrix compact showed extremely good oxidation resistance at 1573 K, although the compact showed poor oxidation resistance at 1023 K.