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 CrNbO4. It has shown that the exclusive formation of CrNbO4 on the Nb-base alloys can be achieved by the volume fraction increasing and the particle size decreasing for NbCr2 phase. Moreover, the barrier effect of Nb5Si3 phase on the diffusion of Cr in Nb-base alloys has also been deduced in this work.