Method for joining components in titanium aluminide by brazing

• US 7,781,696 B2
• Filed: 12/16/2003
• Issued: 08/24/2010
• Est. Priority Date: 12/24/2002
• Status: Active Grant

• Current Assignee: Rolls-Royce Deutschland Limited & Company KG (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce Deutschland Limited & Company KG (Rolls-Royce Holdings Plc)
• Inventors: Schreiber, Karl, Jakobi, Gunther
• Primary Examiner(s): Heinrich; Samuel M
• Application Number:
  US10/735,706
• Publication Number:
  US 20040182843A1
• Time in Patent Office: 2,443 Days
• Field of Search: 21912163-12166, 219/121.85, 228/234.1, 228/262.72
• US Class Current: 219/121.64
• CPC Class Codes: B23K 1/0008 specially adapted for particular articles or work
• CPC Class Codes: B23K 1/0056 soldering by means of beams, e.g. lasers, E.B.
• CPC Class Codes: B23K 2103/14 Titanium or alloys thereof

Abstract

A method for joining components in TiAl with a braze includes heating the braze with a laser.

Claims

1. A method for the joining of TiAl components with a braze having a melting temperature lower than a melting temperature of the TiAl components, comprising:

aligning the TiAl components to form a braze joint therebetween into which molten braze can be deposited;

depositing the braze into the braze joint;

directly heating only the braze with a laser beam to a temperature at which the braze is molten but which temperature is below a melting temperature of the TiAl components, so that the braze adheres to the TiAl components;

preventing primary heat input into the TiAl components and limiting heating of the TiAl components to an amount insufficient to

     1) change a structure of the components; and

     2) substantively change dimensions of the components due to thermal expansion.

2. A method in accordance with claim 1, wherein TiAl sheets are joined.

3. A method in accordance with claim 2, wherein the components are joined with a braze gap.

4. A method in accordance with claim 3, wherein the components are butt-joined.

5. A method in accordance with claim 4, wherein joining is accomplished under protective gas.

6. A method in accordance with claim 5, wherein the components are positioned relative to each other at room temperature and under atmospheric pressure.

7. A method in accordance with claim 6, wherein a ductile braze is used.

8. A method in accordance with claim 7, wherein the molten bath is protected from sagging by a backing bar.

9. A method in accordance with claim 8, wherein the braze is fed in the form of a wire.

10. A method in accordance with claim 8, wherein the braze is fed in the form of powder.

11. A method in accordance with claim 1, wherein the components are joined with a braze gap.

12. A method in accordance with claim 1, wherein the components are butt-joined.

13. A method in accordance with claim 1, wherein joining is accomplished under protective gas.

14. A method in accordance with claim 1, wherein the components are positioned relative to each other at room temperature and under atmospheric pressure.

15. A method in accordance with claim 1, wherein a ductile braze is used.

16. A method in accordance with claim 1, wherein the molten bath is protected from sagging by a backing bar.

17. A method in accordance with claim 1, wherein the TiAl components are joined with a filled joint.

18. A method in accordance with claim 1, wherein the TiAl components are joined by an overlapping joint.

19. A method in accordance with claim 1, wherein the TiAl components are joined without a braze gap.

20. A method in accordance with claim 2, wherein the TiAl components are joined with a filled joint.

21. A method in accordance with claim 2, wherein the TiAl components are joined by an overlapping joint.

22. A method in accordance with claim 2, wherein the TiAl components are joined without a braze gap.

23. A method in accordance with claim 1, wherein the braze is melted prior to deposition into the braze joint.

24. A method in accordance with claim 1, wherein the braze is melted after deposition into the braze joint.

25. A method in accordance with claim 1, wherein the braze is melted during deposition into the braze joint.