Claims
- 1. A method for producing articles of gamma titanium aluminide alloy having improved properties which comprises the steps of:
- (a) shaping said article at a temperature in the approximate range of about 130.degree. C. below the titanium-aluminum eutectoid temperature of said alloy to about 20.degree. C. below the alpha-transus temperature of said alloy;
- (b) heat treating the thus-shaped article at about the alpha-transus temperature of said alloy for about 15 to 120 minutes;
- (c) cooling the heat-treated article at a rate of about 30.degree. to 500.degree. C. per minute; and
- (d) aging the article at a temperature between about 750.degree. and 1050.degree. C. for about 4 to 300 hours.
- 2. The method of claim 1 wherein said article is shaped by extrusion at a temperature in the approximate range of 130.degree. C. below said titanium-aluminum eutectoid to about 20.degree. C. below said alpha-transus.
- 3. The method of claim 1 wherein said article is shaped by isothermal forging at a temperature in the approximate range of 130.degree. C. below said titanium-aluminum eutectoid to about 100.degree. C. above said eutectoid.
- 4. The method of claim 1 wherein said article is shaped by hot die forging at a temperature in the approximate range of 130.degree. C. below said titanium-aluminum eutectoid to about 20.degree. C. below said alpha-transus.
- 5. The method of claim 1 wherein said heat treatment step (b) is carried out at a temperature about 5.degree. below to 20.degree. C. above said alpha-transus.
- 6. A method for producing extruded articles of gamma titanium aluminide alloy having improved properties which comprises the steps of:
- (a) extruding said article at a temperature in the approximate range of 0.degree. to 20.degree. C. below the alpha-transus temperature of said alloy, at an extrusion ratio of about 4:1 to 16:1 and an extrusion rate of about 1-2 cm/second, and
- (b) aging the thus-extruded article at a temperature between about 750.degree. and 1050.degree. C. for about 4 to 300 hours.
RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
US Referenced Citations (4)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0171862 |
Jul 1988 |
JPX |
Non-Patent Literature Citations (3)
Entry |
Maeda et al, Abstract (English): Autumn Symp. Japan Inst. Metals, 1989, pp. 1-8. |
Kim Jour. of Metals, Jul. 1989, p. 24. |
Binary Alloy Phase Diagrams, ed. Massalski et al, ASM, 1986, p. 173 |