Influence of niobium additions on high-temperature-oxidation behavior of Ti{sub 3}Al alloys and coatings
- O.N.E.R.A. Direction Scientifique des Materiaux, Chatillon (France)
- Universite de Nancy, Vandoeuvre (France)
In this study, the oxidation properties of Ti{sub 3}Al + Nb bulk alloys, as well as IMI 829 alloy, coated with a Ti{sub 3}Al + Nb layer, have been considered. Model alloys have been prepared, with 5-25 at.% niobium contents; 50-{mu}m-thick Ti{sub 3}Al + 10 at.% Nb coatings have also been deposited on IMI 829 by triode sputtering. Bulk alloys and coated substrates have been exposed to cyclic and isothermal oxidation in air between 700 and 800{degrees}C. Niobium additions generally caused the oxidation rate of Ti{sub 3}Al to decrease significantly. In all cases rutile is the main oxide formed. It is believed that the ability of niobium to dissolve in the rutile lattice, and therefore to lower the oxygen diffusion rate through the oxide layer, is a contribution to the observed oxidation resistance enhancement. The formation of niobium oxide has also been envisaged for this matter.
- OSTI ID:
- 67833
- Journal Information:
- Oxidation of Metals, Vol. 42, Issue 1-2; Other Information: PBD: Aug 1994
- Country of Publication:
- United States
- Language:
- English
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