Experimental study and modeling of high temperature oxidation of Nb-base in situ composites

The oxidation behavior of Nb-base in situ composites in static air at 1100, 1200 and 1250 °C has been studied. The reaction followed the parabolic rate law. The oxide scales were mainly composed of TiNb2O7, TiNb10O29, TiO2, Nb2O5 and SiO2. The theoretical oxidation model proposed by Gesmundo et al. has been applied to analyze existing oxidation data of Nb-base in situ composites. The result shows that oxidation rate of the Nb-base in situ composites is basically accordance with the analytical results predicted by the theoretical oxidation model to a good approximation.