Brazing composition and method for brazing parts made of alumina-based materials with said composition

• US 6,616,032 B1
• Filed: 06/22/2001
• Issued: 09/09/2003
• Est. Priority Date: 12/23/1998
• Status: Expired due to Fees

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Gasse, Adrien, Eustathopoulos, Nicolas
• Primary Examiner(s): Dunn, Tom
• Assistant Examiner(s): EDMONDSON, LYNNE RENEE
• Application Number:
  US09/869,022
• Time in Patent Office: 809 Days
• Field of Search: 228/248.1, 228/121, 228/122.1, 228/246, 228/262--26, 228/180.22, 228/245, 228/124.6, 420/528, 420/552, 420/585, 148/421, 148/430, 148/433, 148/22-24
• US Class Current: 228/248.1
• CPC Class Codes: B23K 1/19 taking account of the properties of the materials to be soldered
• CPC Class Codes: B23K 35/3033 Ni as the principal constituent
• CPC Class Codes: B23K 35/322 a Pt-group metal as principal constituent
• CPC Class Codes: B23K 35/325 Ti as the principal constituent
• CPC Class Codes: C04B 2235/656 characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/6581 Total pressure below 1 atmosphere, e.g. vacuum
• CPC Class Codes: C04B 2235/6582 Hydrogen containing atmosphere
• CPC Class Codes: C04B 2235/661 Multi-step sintering
• CPC Class Codes: C04B 2237/122 based on refractory metals
• CPC Class Codes: C04B 2237/123 based on iron group metals, e.g. steel
• CPC Class Codes: C04B 2237/125 based on noble metals, e.g. silver
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/402 Aluminium
• CPC Class Codes: C04B 2237/403 Refractory metals
• CPC Class Codes: C04B 2237/405 Iron metal group, e.g. Co or Ni
• CPC Class Codes: C04B 2237/408 Noble metals, e.g. palladium, platina or silver
• CPC Class Codes: C04B 37/006 consisting of metals or metal salts
• CPC Class Codes: C04B 37/026 consisting of metals or metal salts

Abstract

A refractory braze composition and process for assembling alumina-containing parts to another alumina-based material, metal or a metal alloy by reactive or non-reactive refractory brazing using a braze composition provide assemblies entirely of alumina or containing alumina and a metal or metal alloy. The braze composition is non-reactive with alumina or a reactive composition, whose reactivity with alumina is controlled, and it is formed of aluminium, of titanium, and of a matrix made up either of palladium, or of nickel, or of a nickel and palladium alloy.

Claims

1. Refractory braze composition, non-reactive with alumina, whose atomic percentage composition is 2 to 10% aluminium, 2 to 10% titanium and 80 to 96% of a matrix formed either of palladium, or of nickel, or of a nickel and palladium alloy in all proportions.

2. Refractory braze composition, non-reactive with alumina, according to claim 1, whose atomic percentage composition is 2 to 5% aluminium, 2 to 5% titanium, and 90 to 96% of a matrix formed either of palladium, or of nickel, or of a nickel and palladium alloy in all proportions.

6. A process of non-reactive refractory brazing of a first part of an alumina-based material to a second part of an alumina-based material, metal or metal alloy in which said parts are contacted with a non-reactive refractory braze composition according to either of claims 1 and 2, the assembly formed by the parts and the braze composition being heated to a sufficient brazing temperature to melt the braze composition in order to form a refractory joint.

8. Process according to claim 6, in which the brazing temperature ranges from 1400 to 1600°

C.

10. Process according to claim 6, in which the brazing time is 5 to 10 minutes.

11. Process according to claim 6, in which a powder of the braze composition is formed, this powder is placed in suspension with an organic binder and in that the assembly surfaces of the parts to be assembled are coated with the suspension obtained.

12. Process according to claim 6, in which the braze composition is made into foil or strip form.

13. Process according to claim 11, in which said braze composition is placed between the parts to be assembled and/or in their vicinity.

14. Process according to claim 13, in which capillary brazing is conducted.

15. Process according to claim 6, in which said alumina-based material has an alumina content of 90% by weight or more.

16. Process according to claim 6, in which said alumina-based material is chosen from among sapphire, sintered alumina and alumina-based compositions.

17. Process according to claim 16, in which said alumina-based composites are chosen from among Al₂O₃/ZrO₂ composites, Al₂O₃/mullite composites, Al₂O₃/SiC composites and Al₂O₃/Si₃N₄ composites, with Al₂O₃ matrices.

18. Process according to claim 6, in which said metal or metal alloy is chosen from among Ti, Al, Ni, Pt, Mo, Zr and their alloys.

19. Process according to claim 18, in which said metal or metal alloy is chosen from among the refractory intermetallic compounds containing titanium and aluminium;

metal and aluminium;

titanium-based alloys;

platinum and molybdenum.

20. Process according to claim 6, in which brazing is conducted in a vacuum or in a neutral gas or reducing gas atmosphere.

21. Process according to claim 20, in which said gas is chosen from among hydrogen, argon, nitrogen and mixtures thereof.

22. Assembly formed with the process according to claim 6.

3. Reactive refractory braze composition, whose reactivity with alumina is controlled and whose atomic percentage composition is 2 to 48% aluminium, 10 to 96% titanium and 2 to 80% of a matrix formed either of palladium, or of nickel or of a nickel and palladium alloy in all proportions, provided that the atomic percentage of titanium is greater than the atomic percentage of aluminium.

4. Reactive refractory braze composition, according to claim 3, whose reactivity with alumina is controlled and whose atomic percentage composition is 15 to 30% aluminium, 20 '"'"'to 35% titanium and 45 to 60% nickel.

5. Reactive refractory braze composition according to claim 3, whose reactivity with alumina is controlled and whose atomic percentage composition is 2 to 10% aluminium, 35 to 50% titanium, and 45 to 55% nickel.

7. A process of reactive refractory brazing of a first part of an alumina-based material to a second part of an alumina-based material, metal or metal alloy in which said parts are contacted with a refractory braze composition whose reactivity with alumina is controlled, according to any one of claims 3 to 5, and the assembly formed by the parts and the braze composition is heated to a sufficient brazing temperature to cause the braze composition to metal in order to form a refractory joint.

9. Process according to claim 7, in which the brazing temperature ranges from 1000 to 1750°

C.

23. Process according to claim 7, in which the brazing time is 5 to 10 minutes.

24. Process according to claim 7, in which a powder of the braze composition is formed, this powder is placed in suspension with an organic binder and in that the assembly surfaces of the parts to be assembled are coated with the suspension obtained.

25. Process according to claim 23, in which the braze composition is made into foil or strip form.

26. Process according to claim 24, in which said braze composition is placed between the parts to be assembled and/or in their vicinity.

27. Process according to claim 26, in which capillary brazing is conducted.

28. Process according to claim 7, in which said alumina-based material has an alumina content of 90% by weight or more.

29. Process according to claim 7, in which said alumina-based material is chosen from among sapphire, sintered alumina and alumina-based compositions.

30. Process according to claim 29, in which said alumina-based composites are chosen from among Al₂O₃/ZrO₂ composites, Al₂O₃/mullite composites, Al₂O₃/SiC composites and Al₂O₃/Si₃N₄ composites, with Al₂O₃ matrices.

31. Process according to claim 7, in which said metal or metal alloy is chosen from among Ti, Al, Ni, Pt, Mo, Zr and their alloys.

32. Process according to claim 31, in which said metal or metal alloy is chosen from among the refractory intermetallic compounds containing titanium and aluminium, metal and aluminium, titanium-based alloys;

platinum and molybdenum.

33. Process according to claim 7, in which brazing is conducted in a vacuum or in a neutral gas or reducing gas atmosphere.

34. Process according to claim 33, in which said gas is chosen from among hydrogen, argon, nitrogen and mixtures thereof.

35. Assembly formed with the process according to claim 7.