DEVELOPMENT OF OXIDATION-RESISTANT HIGH-TEMPERATURE NBTIAL ALLOYS AND INTERMETALLICS

The effect of alloying elements like Ti, Al, Cr, V and Mo on the oxidation resistance of Nb at high temperature (between 700-degrees-C and 1400-degrees-C) has been studied. The value of the parabolic oxide growth constants, 0.1 g2/cm4 s < K(p) < 100 g2/cm4 s, depends on the nature and morphology of oxides formed in the external scale. The growth of protective oxides, like alumina, requires a high content of alloying elements, which usually means a lower melting point and the formation of brittle phases.