Experimental studies and modeling of the oxidation of multiphase niobium-base alloys

A three-phase oxidation model has been developed for study the oxidation behavior of multiphase alloys. This model has been utilized to identify the oxidation behavior of three-phase Nb-base alloys and successfully predicted the critical value for the exclusive formation of CrNbO 4. It has shown that the exclusive formation of CrNbO 4 on the Nb-base alloys can be achieved by the volume fraction increasing and the particle size decreasing for NbCr 2 phase. Moreover, the barrier effect of Nb 5Si 3 phase on the diffusion of Cr in Nb-base alloys has also been deduced in this work.