Composite crucibles and methods of making and using the same

Patent metadata

Field	Value
Publication number	US-9771637-B2
Application number	US-201414564121-A
Country	US
Kind code	B2
Filing date	Dec 9, 2014
Priority date	Dec 9, 2014
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A composite crucible for growing single crystals comprises an outer crucible of a first material, and an inner liner of a second material having a coefficient of thermal expansion differing from the first material. The outer crucible comprises an inside bore. The inner liner is disposed in the inside bore without diffusion bonding or chemical bonding between the outer crucible and the inner liner. In certain non-limiting embodiments, the first material is one of molybdenum and a molybdenum alloy, and the second material is one of tantalum, niobium, a tantalum alloy, and a niobium alloy.

First claim

What is claimed is:

1. A composite crucible for growing single crystals, the composite crucible comprising:
an outer crucible of a first material, the outer crucible comprising an inside bore; and
an inner liner of a second material having an ASTM drain size of 7 to 14, and a coefficient of thermal expansion differing from the first material, the inner liner disposed in the inside bore without diffusion bonding or chemical bonding between the outer crucible and the inner liner.

2. The composite crucible of claim 1 , wherein the first material is one of molybdenum and a molybdenum alloy.

3. The composite crucible of claim 1 , wherein the second material is one of tantalum, niobium, a tantalum alloy, and a niobium alloy.

4. The composite crucible of claim 1 , wherein the second material is C-103 niobium alloy.

5. The composite crucible of claim 1 , wherein the inner liner is retained in the inside bore of the outer crucible by an interference fit.

6. The composite crucible of claim 1 , wherein the outer crucible and the inner crucible can expand and contract independent of one another in response to changes in temperature.

7. The composite crucible of claim 1 , wherein the outer crucible has a thickness greater than the inner liner.

8. The composite crucible of claim 1 , wherein the second material has an ASTM grain size of 10 to 14.

9. The composite crucible of claim 1 , wherein the second material is one of a tantalum alloy and a niobium alloy, and wherein the second material comprises at least one of silicon and thorium.

10. The composite crucible of claim 1 , wherein the second material is one of a tantalum alloy and a niobium alloy, and wherein the second material comprises greater than 0 up to 700 ppm silicon.

11. The composite crucible of claim 1 , wherein the second material is one of a tantalum alloy and a niobium alloy, and wherein the second material comprises greater than 0 up to 500 ppm thorium.

12. The composite crucible of claim 1 , wherein the inner liner is carburized prior to use.

13. The composite crucible of claim 12 , wherein the inner liner is carburized by heating the inner liner in a carbon-containing atmosphere.

14. The composite crucible of claim 12 , wherein the inner liner is carburized at a temperature of 2200° C. to 2500° C.

15. A method for forming a composite crucible for growing single crystals, the method comprising:
providing an outer crucible including an inside bore, wherein the outer crucible comprises a first material selected from molybdenum and a molybdenum alloy;
providing a preform blank of a second material selected from tantalum, niobium, a tantalum alloy, and a niobium alloy;
flowforming the preform blank at a temperature below the recrystallization temperature of the second material to provide an inner liner sized to fit in the inside bore of the outer crucible; and
disposing the inner liner in the inside bore without diffusion bonding or chemical bonding between the outer crucible and the inner liner.

16. The method of claim 15 , wherein the second material is C-103 niobium alloy.

17. The method of claim 15 , wherein the second material is one of a tantalum alloy and a niobium alloy, and wherein the second material further comprises at least one of silicon and thorium.

18. The method of claim 15 , wherein the second material is one of a tantalum alloy and a niobium alloy, and wherein the second material comprises greater than 0 up to 700 ppm silicon.

19. The method of claim 15 , wherein the second material is one of a tantalum alloy and a niobium alloy, and wherein the second material comprises greater than 0 up to 500 ppm thorium.

20. The method of claim 15 , further comprising, after flowforming the preform blank to provide the inner liner, carburizing the inner liner prior to use.

21. The method of claim 20 , wherein carburizing the inner liner comprises heating the inner liner in a carbon-containing atmosphere.

22. The method of claim 20 , wherein carburizing the inner liner comprises carburizing the inner liner at a temperature of 2200° C. to 2500° C.

23. The method of claim 15 , wherein the second material has an ASTM grain size of 7 to 14.

24. The method of claim 15 , wherein the second material has an ASTM grain size of 10 to 14.

25. A method for growing single crystals, the method comprising:
melting a feed material in an inner liner of a composite crucible to provide a molten composition, wherein the composite crucible comprises an outer crucible including an inside bore, the outer crucible comprises a first material, the inner liner comprises a second material having an ASTM grain size of 7 to 14, and a coefficient of thermal expansion differing from the first material, and the inner liner is disposed in the inside bore without diffusion bonding or chemical bonding between the outer crucible and the inner liner; and
crystallizing at least a portion of the molten composition to form single crystals.

26. The method of claim 25 , wherein the first material is one of molybdenum and a molybdenum alloy.

27. The method of claim 25 , wherein the second material is one of tantalum, niobium, a tantalum alloy, and a niobium alloy.

28. The method of claim 25 , wherein the second material is C-103 niobium alloy.

29. The method of claim 25 , wherein the inner liner is retained in the inside bore of the outer crucible by an interference fit.

30. The method of claim 25 , wherein the outer crucible has a thickness greater than the inner liner.

31. The method of claim 25 , wherein the second material is one of a tantalum alloy and a niobium alloy, and wherein the second material comprises at least one of silicon and thorium.

32. The method of claim 25 , wherein the second material is one of a tantalum alloy and a niobium alloy, and wherein the second material comprises greater than zero up to 700 ppm silicon.

33. The method of claim 25 , wherein the second material is one of a tantalum alloy and a niobium alloy, and wherein the second material comprises greater than 0 up to 500 ppm thorium.

34. The method of claim 25 , wherein the inner liner is a flowformed inner liner.

35. The method of claim 25 , wherein the inner liner is a carburized inner liner.

36. The method of claim 25 , wherein the inner liner is a carburized flowformed inner liner.

37. The method of claim 25 , wherein the second material has an ASTM grain size of 10 to 14.

38. The method of claim 25 , wherein the single crystals are selected from sapphire crystals, aluminum nitrate, silicon, and ruby crystals.

39. A composite crucible for growing single crystals, the composite crucible comprising:
an outer crucible of a first material comprising an inside bore; and
an inner liner of a second material having a coefficient of thermal expansion differing from the first material, the inner liner disposed in the inside bore without diffusion bonding or chemical bonding between the outer crucible and the inner liner, wherein the second material is one of tantalum, niobium, a tantalum alloy, and a niobium alloy.

40. The composite crucible of claim 39 , wherein the first material is selected from molybdenum and a molybd

Assignees

• Ati Properties Llc

Inventors

• Fonte Matthew V

Classifications

• B32B15/01

  all layers being exclusively metallic {(making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00)} · CPC title

• C30B35/002

  Crucibles or containers · CPC title

• C22C27/04

  Alloys based on tungsten or molybdenum · CPC title

• C22C27/02 Primary

  Alloys based on vanadium, niobium, or tantalum · CPC title