Claims
- 1. A process for producing duplex microstructure in an article of gamma titanium aluminide alloy containing 0.05 to 1.0 atomic percent boron, which comprises the steps of:(a) hot working the article; (b) annealing the hot worked article at an annealing temperature in the range of Te+100° C. to Tα−25° C. for about 10 minutes to 15 hours; (c) cooling said article from said annealing temperature to a preselected temperature between said annealing temperature and about 700° C. at a first cooling rate of about 10° to 1000° C./min and then cooled at a second rate ranging from said first cooling rate to water quenching to room temperature, and (d) aging the so cooled article at an aging temperature in the range of 700° to 1050° C. for about 1 to 150 hours.
- 2. The process of claim 1 wherein said alloy has the composition Ti-(45.0-49)Al-(0-3)X-(0-6)Y-(0.05-1.0)B wherein X is Cr, Mn, V or any combination thereof, and Y is Nb, Ta, W, Mo, Zr, Hf, or any combination thereof.
- 3. The process of claim 2 wherein said alloy has the composition Ti-(46-47.5)Al-(1-3)Cr-(2-4)Nb-(0-0.3)W-(0.1-0.5)B.
- 4. A process for producing duplex microstructure in an article of gamma titanium aluminide alloy containing 0.05 to 1.0 atomic percent boron, which comprises the steps of:(a) hot working the article; (b) annealing the hot worked article at an annealing temperature in the range of Te+100° C. to Tα−25° C. for about 10 minutes to 15 hours; (c) cooling said article from said annealing temperature to an aging temperature in the range of 700° to 1050° C. at a cooling rate of about 5° to 1000° C./min; and (d) aging the so cooled article at said aging temperature for about 1 to 150 hours.
- 5. The process of claim 4 wherein said alloy has the composition Ti-(45.0-49)Al-(0-3)X-(0-6)Y-(0.05-1.0)B wherein X is Cr, Mn, V or any combination thereof, and Y is Nb, Ta, W, Mo, Zr, Hf, or any combination thereof.
- 6. The process of claim 5 wherein said alloy has the composition Ti-(46-47.5)Al-(1-3)Cr-(2-4)Nb-(0-0.3)W-(0.1-0.5)B.
- 7. A process for producing nearly-lamellar microstructure in an article of gamma titanium aluminide alloy containing 0.05 to 1.0 atomic percent boron, which comprises the steps of:(a) hot working the article; (b) annealing the hot worked article at an annealing temperature in the range of Tα−1° C. to Tα−25° C. for about 0.5 to 10 hours; (c) cooling said article from said annealing temperature to a preselected temperature between said annealing temperature and about 700° C. at a first cooling rate of about 5° to 1000° C./min and then cooled at a second rate ranging from said first cooling rate to water quenching to room temperature; and (d) aging the so cooled article at an aging temperature in the range of 700° to 1050° C. for about 1 to 150 hours.
- 8. The process of claim 7 wherein said alloy has the composition Ti-(45.0-49)Al-(0-3)X-(0-6)Y-(0.05-1.0)B wherein X is Cr, Mn, V or any combination thereof, and Y is Nb, Ta, W, Mo, Zr, Hf, or any combination thereof.
- 9. The process of claim 8 wherein said alloy has the composition Ti-(46-47.5)Al-(1-3)Cr-(2-4)Nb-(0-0.3)W-(0.1-0.5)B.
- 10. A process for producing nearly-lamellar microstructure in an article of gamma titanium aluminide alloy containing 0.05 to 1.0 atomic percent boron, which comprises the steps of:(a) hot working the article; (b) annealing the hot worked article at an annealing temperature in the range of Tα−1° C. to Tα−25° C. for about 0.5 to 10 hours; (c) cooling said article from said annealing temperature to an aging temperature in the range of 700° to 1050° C. at a cooling rate of about 5° to 1000° C./min; and (d) aging the so cooled article at said aging temperature for about 1 to 150 hours.
- 11. The process of claim 10 wherein said alloy has the composition Ti-(45.0-49)Al-(0-3)X-(0-6)Y-(0.05-1.0)B wherein X is Cr, Mn, V or any combination thereof, and Y is Nb, Ta, W, Mo, Zr, Hf, or any combination thereof.
- 12. The process of claim 11 wherein said alloy has the composition Ti-(46-47.5)Al-(1-3)Cr-(2-4)Nb-(0-0.3)W-(0.1-0.5)B.
- 13. A process for producing fully TMT lamellar microstructure in an article of gamma titanium aluminide alloy containing 0.05 to 1.0 atomic percent boron, which comprises the steps of:(a) hot working the article; (b) pre-annealing the hot worked article at a temperature in the range of Tα−12 C. to Tα−100° C. for about 1 minute to 2 hours; (c) heating the pre-annealed article to annealing temperature at a rate greater then 20° C./min; (d) annealing the hot worked article at an annealing temperature in the range of Tα to Tα+60° C. for about 1 minute to 10 hours; (e) cooling said article from said annealing temperature to a preselected temperature between said annealing temperature and about 700° C. at a first cooling rate of about 5° to 1000° C./min and then cooled at a second rate ranging from said first cooling rate to water quenching to room temperature; and (f) aging the cooled article at an aging temperature in the range of 700° to 1050° C. for about 1 to 150 hours.
- 14. The process of claim 13 wherein said alloy has the composition Ti-(45.0-49)Al-(0-3)X-(0-6)Y-(0.05-1.0)B wherein X is Cr, Mn, V or any combination thereof, and Y is Nb, Ta, W, Mo, Zr, Hf, or any combination thereof.
- 15. The process of claim 14 wherein said alloy has the composition Ti-(46-47.5)Al-(1-3)Cr-(2-4)Nb-(0-0.3)W-(0.1-0.5)B.
- 16. A process for producing fully TMT lamellar microstructure in an article of gamma titanium aluminide alloy containing 0.05 to 1.0 atomic percent boron, which comprises the steps of:(a) hot working the article; (b) pre-annealing the hot worked article at a temperature in the range of Tα−1° C. to Tα−100° C. for about 1 minute to 2 hours; (c) heating the pre-annealed article to annealing temperature at a rate greater than 20° C./min; (d) annealing the hot worked article at an annealing temperature in the range of Tα to Tα+60° C. for about 1 minute to 10 hours; (e) cooling said article from said annealing temperature to an aging temperature in the range of 700° to 1050° C. at a cooling rate of about 5° to 1000° C./min; and (f) aging the cooled article at said aging temperature for about 1 to 150 hours.
- 17. The process of claim 16 wherein said alloy has the composition Ti-(45.0-49)Al-(0-3)X-(0-6)Y-(0.05-1.0)B wherein X is Cr, Mn, V or any combination thereof, and Y is Nb, Ta, W, Mo, Zr, Hf, or any combination thereof.
- 18. The process of claim 17 wherein said alloy has the composition Ti-(46-47.5)Al-(1-3)Cr-(2-4)Nb-(0-0.3)W-(0.1-0.5)B.
- 19. A process for producing fully lamellar microstructure in an article of gamma titanium aluminide alloy containing 0.05 to 1.0 atomic percent boron, which comprises the steps of:(a) hot working the article; (b) heating the said article to annealing temperature at a rate greater than 20° C./min; (c) annealing the hot worked article at an annealing temperature in the range of Tα to Tα+60° C. for about 1 minute to 10 hours; (d) cooling said article from said annealing temperature to a preselected temperature between said annealing temperature and about 700° C. at a first cooling rate of about 5° to 1000° C./min and then cooled at a second rate ranging from said first cooling rate to water quenching to room temperature; and (e) aging the cooled article at an aging temperature in the range of 700° to 1050° C. for about 1 to 150 hours.
- 20. The process of claim 19 wherein said alloy has the composition Ti-(45.0-49)Al-(0-3)X-(0-6)Y-(0.05-1.0)B wherein X is Cr, Mn, V or any combination thereof, and Y is Nb, Ta, W, Mo, Zr, Hf, or any combination thereof.
- 21. The process of claim 20 wherein said alloy has the composition Ti-(46-47.5)Al-(1-3)Cr-(2-4)Nb-(0-0.3)W-(0.1-0.5)B.
- 22. A process for producing fully lamellar microstructure in an article of gamma titanium aluminide alloy containing 0.05 to 1.0 atomic percent boron, which comprises the steps of:(a) hot working the article; (b) heating the said article to annealing temperature at a rate greater than 20° C./min; (c) annealing the hot worked article at an annealing temperature in the range of Tα to Tα+60° C. for about 1 minute to 10 hours; (d) cooling said article from said annealing temperature to an aging temperature in the range of 700° to 1050° C. at a cooling rate of about 5° to 1000° C./min; and (e) aging the cooled article at said aging temperature for about 1 to 150 hours.
- 23. The process of claim 22 wherein said alloy has the composition Ti-(45.0-49)Al-(0-3)X-(0-6)Y-(0.05-1.0)B wherein X is Cr, Mn, V or any combination thereof, and Y is Nb, Ta, W, Mo, Zr, Hf, or any combination thereof.
- 24. The process of claim 23 wherein said alloy has the composition Ti-(46-47.5)Al-(1-3)Cr-(2-4)Nb-(0-0.3)W-(0.1-0.5)B.
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 (7)