Claims
- 1. A beta phase NiAl intermetallic alloy consisting essentially of, in atomic percent, about 45-59% Ni, about 0.1-10% of at least two elements selected from the group consisting of Ga, Hf, and Ti, up to 1% Zr, up to 5% Ta, up to 5% Nb, up to 5% V, with the balance Al and incidental impurities;
- when selected the:
- Ga being about 0.02-0.5%,
- Hf being about 0.2 to less than about 1%, and,
- Ti being about 0.1-10%,
- when included the:
- Zr being about 0.1-1%,
- Ta being about 0.1-5%,
- Nb being about 0.1-5%, and,
- V being about 0.1-5%;
- the intermetallic alloy characterized by having, in combination,:
- a) a microstructure consisting essentially of an NiAl beta matrix phase and at least one precipitate phase in the NiAl beta matrix, and
- b) an average stress rupture life of at least about 25 hours when tested at 1600.degree. F. under a stress of about 35 ksi.
- 2. The alloy of claim 1 in which about 0.02-0.5% Ga and about 0.25 to less than 1% Hf are selected.
- 3. The alloy of claim 1 in which about 0.02-0.5% Ga and about 0.1-10% Ti are selected.
- 4. The alloy of claim 1 comprising, in atomic percent, about 45-59% Ni, about 0.02-0.5% Ga, about 0.25 to less than 1% Hf, about 0.1-10% Ti, with the balance Al and incidental impurities.
- 5. The alloy of claim 4 in which the Ga is about 0.05-0.2%, the Hf is about 0.25-0.8%, and the Ti is about 1-8%.
- 6. The alloy of claim 5 in which the Ga is about 0.05-0.2%, the Hf is about 0.5%, and the Ti is about 1-5%.
- 7. A beta phase intermetallic article having the composition, microstructure and properties of claim 1.
- 8. The article of claim 7 in the form of a single crystal.
- 9. The article of claim 8 in which the article is at least an airfoil portion of a gas turbine engine turbine component.
Government Interests
The Government has rights in this invention pursuant to Contract No. F33615-90-C-2006 awarded by the Department of the Air Force.
US Referenced Citations (5)
Non-Patent Literature Citations (2)
Entry |
CAbs. 120:141287 1994. |
J of the Korean Inst. of Met. & Mater V 31, No. 6 (1993) 810-817. |