Abstract
The oxidation characteristics of Ti-14Al-21Nb has been studied with an emphasis on the influence of nitrogen. The oxidation curve in N2-21%O2 is significantly lower than in O2 or in Ar-21%O2 at 1300 K. At the scale/substrate interface, two thin continuous layers and an Al-enriched layer were formed. These three layers were identified as/TiN/Nb2Al/TiAl/ by XRD, EPMA, SEM, and optical observation. The oxidation rate is reduced by the formation of the TiN layer, although the oxidation of bulk material of TiN is as fast as Ti Alloy. This difference can be explained by such a low oxygen partial pressure at the interface that the TiN layer is kept intact.
