Development of Nb Based Alloys for High Temperature Oxidation Resistance in Air

DOI: 10.5176/2251-1857_M343

Authors: Shailendra Varma, Benedict Portillo, David Alvarez and Alma Vazquez

Abstract:

The oxidation resistance of several Nb based alloys have been determined in air from 700-1400oC. Pesting at low temperature and high temperature oxide spalling are the major problems encountered in these alloys. Some examples of the alloys from Nb-Cr-Si system containing, Mo, Al, Hf, and B have been discussed in this paper for presentation. B addition can be beneficial in the presence of Mo while Al introduces the problems of internal oxidation by the formation of Al2O3 at the interphase interfaces. Oxidation of Hf has been found to be detrimental to the overall oxidation of the alloys.

Keywords:

pesting; spallation; SEM; x-ray mapping; oxidation