Claims
- 1. Method of forming a thermionic cathode with an active region comprising the steps of:
- forming a porous billet;
- impregnating said porous billet with impregnants having a predetermined stoichiometry and in such a quantity such that the active region includes a mixture of at least first and second compounds exhibiting properties of an oxygen deficient material and at least one third compound exhibiting properties of an oxygen sufficient material and an emissive material after sintering said billet and impregnant at a predetermined temperature; and
- sintering said billet and impregnant at a predetermined temperature.
- 2. Method according to claim 1 wherein an emissive surface is formed on said active region.
- 3. Method according to claim 2 wherein said active region is formed using an active metal.
- 4. Method according to claim 3 wherein said active region is formed with at least one impregnant.
- 5. Method according to claim 4 wherein a plurality of layers are formed.
- 6. Method according to claim 5 wherein one of said layers being formed is Y.sub.2 WO.sub.6.
- 7. Method according to claim 5 wherein one of said layers being formed is Al and Sc.
- 8. Method according to claim 5 wherein one of said layers being formed is Ba.
- 9. Method according to claim 5 wherein one of said layers being formed is selected from the group consisting of Ir, O.sub.3, Ru and Rh.
- 10. Method according to claim 5 wherein one of said layers being formed is Ba in the presence of BaO.
- 11. Method according to claim 5 wherein one of said layers being formed is AlWO.sub.4 and Ba.
- 12. Method according to claim 1 wherein a plurality of metal oxide additives are added during the impregnating step.
- 13. Method according to claim 12 said porous billet provides a site for said active region.
- 14. Method according to claim 13 wherein said impregnant is regenerated.
- 15. Method according to claim 12 wherein one of said metal oxide additives include Al.sub.2 (WO.sub.4).sub.3.
- 16. Method according to claim 12 wherein one of said metal oxide additives include Sc.sub.2 (WO.sub.4).sub.3.
- 17. Method according to claim 12 wherein one of said metal oxide additives include R.sub.2 (WO.sub.4).sub.3 which forms RWO.sub.4 when R=M.sup.3+.
- 18. Method according to claim 12 wherein one of said metal oxide additives include BaGa.sub.4.
- 19. Method according to claim 12 wherein one of said metal oxide additives include Ba.sub.10 Ga.
- 20. Method according to claim 12 wherein one of said metal oxide additives include WAl.sub.12.
- 21. Method according to claim 12 wherein one of said metal oxide additives include Al.sub.6 W.
- 22. Method according to claim 12 wherein one of said metal oxide additives include W-Ir.
- 23. Method according to claim 12 wherein one of said metal oxide additives include WOs.sub.2.
- 24. A method of making a thermionic cathode having an active region comprising the steps of:
- boring a billet;
- mixing at least a first compound of a material exhibiting the properties of oxygen deficient compounds, at least a second compound exhibiting the properties of oxygen sufficient compounds, and at least one emissive material within said billet; and
- sintering said billet.
- 25. Method according to claim 24 further including the step of mixing active metal oxides and metals in the billet prior to sintering.
- 26. Method according to claim 25 wherein the second compound is Ba.sub.3 Al.sub.2 O.sub.6.
- 27. Method according to claim 25 wherein the second compound is a mixture of BaIrO.sub.3 and Ba.sub.2 Sc.sub.2 O.sub.6.
- 28. Method according to claim 1 wherein said impregnants include BaTiO.sub.3, Ba, and BaWO.sub.4.
- 29. Method according to claim 1 wherein said impregnants include Ba.sub.2 Y.sub.2 O.sub.5.
- 30. Method according to claim 1 wherein said impregnants include BaSc.sub.2 O.sub.4, BaWO.sub.4 and Ba.
- 31. Method according to claim 1 wherein said impregnant includes a compound selected from the group of barium chromates consisting of BaCr.sub.2 O.sub.4, Ba(CrO.sub.4), Ba.sub.3 Cr.sub.2 O.sub.6, BaCrO.sub.4 and BaCrO.sub.3 which react to form Cr.sub.2 O.sub.2.
- 32. Method according to claim 1 wherein said impregnant includes Gd.sub.2 Ir.sub.2 O.sub.7.
- 33. Method according to claim 1 wherein said impregnant includes Al.sub.2 (WO.sub.4).sub.3 and Ba.
- 34. Method according to claim 1 wherein said impregnant includes Al.sub.2 (WO.sub.4).sub.3 and Sc.
- 35. Method according to claim 1 wherein said impregnant includes Al.sub.2 WO.sub.4, WO.sub.2 and Ba.
- 36. Method according to claim 1 wherein said impregnant includes ScWO.sub.4, WO.sub.2 and Ba.
- 37. Method according to claim 1 wherein said impregnant includes ScWO.sub.4, WO.sub.2 and Sc.
- 38. Method according to claim 1 wherein said impregnant includes ScWO.sub.4, WO.sub.2 and Ba.
- 39. Method according to claim 1 wherein said impregnant includes Ga.sub.2 (WO.sub.4).sub.3 and Ba.
- 40. Method according to claim 1 wherein said impregnant includes Ga.sub.2 (WO.sub.4).sub.3 and Sc.
- 41. Method according to claim 1 wherein said impregnant includes Ga.sub.2 WO.sub.4 and Ba.
- 42. Method according to claim 1 wherein said impregnant includes Ga.sub.2 WO.sub.4 and Sc.
- 43. Method according to claim 1 wherein said impregnant includes RE(WO.sub.4).sub.3 and Ba, wherein RE is a rare earth metal.
- 44. Method according to claim 1 wherein said impregnant includes RE(WO.sub.4).sub.3 and Sc, wherein RE is a rare earth metal.
- 45. Method according to claim 1 wherein said porous billet is formed of MoO.sub.2.
- 46. Method according to claim 1 wherein said porous billet is formed of UO.sub.2.
- 47. Method according to claim 1 wherein said porous billet is formed of any combination of MoO.sub.2 and UO.sub.2.
- 48. Method according to claim 1 wherein said porous billet is formed of BaAl.
- 49. Method according to claim 1 wherein said porous billet is formed of W.
- 50. Method according to claim 1 wherein a top layering of emissive material coats an upper surface of said porous billet said top layering being formed of W mixed directly with BaW, said oxygen deficient material and said oxygen sufficient material.
- 51. Method according to claim 1 wherein said porous billet is being shaped as a rectangle.
- 52. Method according to claim 1 wherein said porous billet is being shaped as a disc.
- 53. Method according to claim 1 further comprising the step of depositing a layer of emission enhancing metal selected from the group consisting of Ir, Os, Ru, Rh and U.
DIVISIONAL APPLICATION
This application is a divisional application of U.S. patent application Ser. No. 08/647,502 filed on May 14, 1996, which was allowed and issued as U.S. Pat. No. 5,828,164, which was a continuation in part of U.S. Patent and Trademark Office application No. 08/218,533, now abandoned, originally entitled, "Improved Thermionic Cathode and Method of Making Same," filed on Mar. 28, 1994, which title was amended to "Improved Thermionic Cathode Using Oxygen Deficient and Fully Oxidized Material to Enhance Emissions." That application is a continuation in part of U.S. Patent and Trademark Office application No. 07/866,773, entitled, "Method of Preparing an Impregnated Cathode with an Enhanced Thermionic Emission from a Porous Billet and Cathode so Prepared," filed Apr. 3, 1992, and issued as U.S. Pat. No. 5,298,830 on Mar. 29, 1994. This divisional application is being filed under 37 C.F.R. .sctn.1.53 and priority from U.S. Patent and Trademark Office application No. 07/866,773 is hereby claimed.
GOVERNMENT INTEREST
The invention described herein may be manufactured, used, and licensed by or for the Government of the United States of America without the payment to us of any royalty thereon.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
5132081 |
Lee |
Jul 1992 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
647502 |
May 1996 |
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Continuation in Parts (2)
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Number |
Date |
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Parent |
218533 |
Mar 1994 |
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Parent |
866773 |
Apr 1992 |
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