Conductive element and method of making

• US 20060022595A1
• Filed: 07/27/2004
• Published: 02/02/2006
• Est. Priority Date: 07/27/2004
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Bewlay, Bernard Patrick, Knudsen, Bruce Alan, Jackson, Melvin Robert, Brewer, James Anthony
• Granted Patent: US 7,358,674 B2
• Time in Patent Office: Days
• US Class Current: 313/623
• CPC Class Codes: C23C 28/021 including at least one metal alloy layer
• CPC Class Codes: C23C 28/023 only coatings of metal elements only
• CPC Class Codes: C23C 28/321 with at least one metal alloy layer
• CPC Class Codes: C23C 28/322 only coatings of metal elements only
• CPC Class Codes: C23C 28/34 including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: H01B 1/023 Alloys based on aluminium
• CPC Class Codes: H01J 61/36 Seals between parts of vessels; Seals for leading-in conductors; Leading-in conductors
• CPC Class Codes: H01J 9/28 Manufacture of leading-in conductors
• CPC Class Codes: Y10T 428/12438 Composite
• CPC Class Codes: Y10T 428/12826 Group VIB metal-base component
• CPC Class Codes: Y10T 428/12875 Platinum group metal-base component

Abstract

A conductive element comprises a metal core and a coating, wherein the coating comprises at least one layer of aluminum, an aluminum alloy, an aluminide, silicon, a silicon alloy, a silicide, and combinations thereof, and wherein the at least one layer has a predetermined thickness. A method of making a conductive element comprises depositing a coating material on a metal core to form a coated metal core and heating the coated metal core to a predetermined temperature to form at least one layer of aluminum, an aluminum alloy, an aluminide, silicon, a silicon alloy, a silicide, and combinations thereof.

Claims

1. A conductive element comprising a metal core and a coating, wherein the coating comprises at least one layer of aluminum, an aluminum alloy, an aluminide, silicon, a silicon alloy, a silicide, and combinations thereof, and wherein the at least one layer has a predetermined thickness.

2. The conductive element according to claim 1, wherein the metal core comprises a metal that is selected from the group consisting of niobium, tungsten, molybdenum, combinations thereof, and alloys thereof.

3. The conductive element according to claim 1, wherein the aluminide comprises an aluminide of at least one of chromium, titanium, niobium, zirconium, hafnium, iron, tin, yttrium, combinations thereof, and alloys thereof.

4. The conductive element according to claim 3, wherein the aluminide is a titanium aluminide.

5. The conductive element according to claim 3, wherein the aluminide is a niobium aluminide.

6. The conductive element according to claim 1, wherein the aluminide layer is formed from a layer of an aluminum coating on the metal core.

7. The conductive element according to claim 1, wherein the aluminide layer has been formed from a layer of an aluminum alloy coating on the metal core.

8. The conductive element according to claim 1, wherein the silicide comprises a silicide of at least one of aluminum, chromium, titanium, germanium, niobium, iron, hafnium, zirconium, combinations thereof, and alloys thereof.

9. The conductive element according to claim 8, wherein the silicide is niobium-chromium-titanium silicide.

10. The conductive element according to claim 8, wherein the silicide is niobium-chromium-titanium-iron silicide.

11. The conductive element according to claim 1, wherein the silicide layer has been formed from a layer of a silicon coating on the metal core.

12. The conductive element according to claim 1, wherein the silicide layer has been formed from a layer of a silicon alloy coating on the metal core.

13. The conductive element according to claim 1, wherein the predetermined thickness of the at least one layer is about 5 micrometers to about 500 micrometers.

14. The conductive element according to claim 13, wherein the predetermined thickness of the at least one layer is about 30 micrometers to about 300 micrometers.

15. The conductive element according to claim 14, wherein the predetermined thickness of the at least one layer is about 50 micrometers to about 150 micrometers.

62. An article of manufacture comprising the conductive element of claim 1.

63. The article of manufacture according to claim 62, wherein the article of manufacture is selected from a group consisting of lamps, electric motors, sensors, and thermocouples.

16. A structure comprising:

a sealed envelope that is transparent or translucent;

at least two electrode tips disposed within the sealed envelope; and

at least two conductive feedthroughs, each of which is coupled to one of the at least two electrode tips, comprising a metal core and a coating, wherein the coating comprises at least one layer of aluminum, an aluminum alloy, an aluminide, silicon, a silicon alloy, a silicide, and combinations thereof, and wherein the at least one layer has a predetermined thickness.

17. The structure according to claim 16, wherein the sealed envelope comprises a material selected from the group consisting of quartz, polycrystalline alumina, micro grain polycrystalline alumina, yttria, yttrium aluminum garnet, and ytterbium aluminum garnet.

18. The structure according to claim 16, wherein the at least two electrode tips comprises molybdenum.

19. The structure according to claim 16, wherein the at least two electrode tips comprises tungsten.

20. The structure according to claim 16 further comprising a dosing substance disposed within the sealed envelope.

21. The structure according to claim 20, wherein the dosing substance comprises a luminous gas.

22. The structure according to claim 16, wherein the metal core comprises a metal selected from the group consisting of niobium, tungsten, molybdenum, combinations thereof, and alloys thereof

23. The structure according to claim 16, wherein the aluminide comprises an aluminide of at least one of chromium, titanium, niobium, zirconium, hafnium, iron, tin, yttrium, combinations thereof, and alloys thereof.

24. The structure according to claim 23, wherein the aluminide is a titanium aluminide.

25. The structure according to claim 23, wherein the aluminide is a niobium aluminide.

26. The structure according to claim 16, wherein the aluminide layer has been formed from a layer of an aluminum coating on the metal core.

27. The structure according to claim 16, wherein the aluminide layer has been formed from a layer of an aluminum alloy coating on the metal core.

28. The structure according to claim 16, wherein the silicide comprises a silicide of at least one of aluminum, chromium, titanium, germanium, niobium, iron, hafnium, zirconium, combinations thereof, and alloys thereof.

29. The structure according to claim 28, wherein the silicide is niobium-chromium-titanium silicide.

30. The structure according to claim 28, wherein the silicide is niobium-chromium-titanium-iron silicide.

31. The structure according to claim 16, wherein the silicide layer has been formed from a layer of a silicon coating on the metal core.

32. The structure according to claim 16, wherein the silicide layer has been formed from a layer of a silicon alloy coating on the metal core.

33. The structure according to claim 16, wherein the predetermined thickness of the at least one layer is about 5 micrometers to about 500 micrometers.

34. The structure according to claim 33, wherein the predetermined thickness of the at least one layer is about 30 micrometers to about 300 micrometers.

35. The structure according to claim 34, wherein the predetermined thickness of the at least one layer is about 50 micrometers to about 150 micrometers.

36. The structure according to claim 16, wherein the structure is a high intensity discharge lamp.

37. The structure according to claim 16, wherein the structure is a ceramic metal halide lamp.

38. The structure according to claim 16, wherein the structure is a high-pressure sodium lamp.

39. The structure according to claim 16, wherein the structure is an automotive lamp.

40. The structure according to claim 16, wherein the sealed envelope and the conductive feedthrough are exposed to air.

41. A method of making a conductive element, the method comprising:

providing a metal core;

providing a coating material comprising at least one of aluminum and silicon, and combinations thereof;

depositing the coating material on the metal core to form a coated metal core; and

heating the coated metal core to a predetermined temperature in an inert atmosphere to form at least one layer of aluminum, an aluminum alloy, an aluminide, silicon, a silicon alloy, a silicide, and combinations thereof.

42. The method according to claim 41, wherein the coating material further comprises at least one of chromium, titanium, germanium, niobium, iron, tin, yttrium, and combinations thereof, and alloys thereof.

43. The method according to claim 41, wherein the metal core comprises a metal that from a group consisting of niobium, tungsten, molybdenum, combinations thereof, and alloys thereof.

44. The method according to claim 41, wherein the depositing comprises a method selected from the group consisting of chemical vapor deposition, physical vapor deposition, slurry coating, spray coating, pack cementation, and combinations thereof.

45. The method according to claim 41, wherein the predetermined temperature is in a range from about 100°

C. to about 1500°

C.

46. The method according to claim 41, wherein the inert atmosphere comprises argon, helium, neon, krypton, xenon, and combinations thereof.

47. A method of making a conductive feedthrough for a lamp, the method comprising:

providing a niobium alloy core;

providing at least one precursor of a coating material in a slurry;

depositing the slurry on the niobium alloy core such that the niobium alloy core is covered by the slurry; and

heating the niobium alloy core covered by the slurry at a predetermined temperature in an inert atmosphere for a predetermined period of time to form a coating on the niobium alloy core.

48. The method according to claim 47, wherein the at least one precursor of a coating material comprises a metal elemental powder.

49. The method according to claim 47, wherein the metal elemental powder comprises at least one of aluminum, chromium, silicon, titanium, germanium, niobium, iron, tin, and yttrium.

50. The method according to claim 47, wherein the coating material comprises at least one alloy precursor.

51. The method according to claim 47, wherein the metal precursor comprises at least one of aluminum, chromium, silicon, titanium, germanium, niobium, iron, tin, and yttrium, combinations thereof, alloys thereof.

52. The method according to claim 47, wherein the slurry is formed by mixing the at least one precursor with a medium.

53. The method according to claim 52, wherein the medium comprises at least one of acid, alcohol, water, and combinations thereof.

54. The method according to claim 47, wherein the method further comprises adding a binder to the slurry.

55. The method according to claim 54, wherein the binder is magnesium oxide.

56. The method according to claim 47, wherein the depositing comprises immersing the metal core in the slurry for a time in a range from about 30 seconds to 1 hour.

57. The method according to claim 47, wherein the heating is carried out in a vacuum heating furnace.

58. The method according to claim 47, wherein the predetermined temperature is in a range from about 100°

C. to about 1500°

C.

59. The method according to claim 47, wherein the predetermined period of time is in a range from about 30 minutes to about 5 hours.

60. The method according to claim 59, wherein the predetermined period of time is in a range from about 1 hour to about 3 hours.

61. The method according to claim 47, wherein the inert atmosphere comprises argon, helium, neon, krypton, xenon, and combinations thereof.