US2677873A - Method of making nickel sponge cathodes - Google Patents
Method of making nickel sponge cathodes Download PDFInfo
- Publication number
- US2677873A US2677873A US640277A US64027746A US2677873A US 2677873 A US2677873 A US 2677873A US 640277 A US640277 A US 640277A US 64027746 A US64027746 A US 64027746A US 2677873 A US2677873 A US 2677873A
- Authority
- US
- United States
- Prior art keywords
- sleeve
- mixture
- cathode
- particles
- nickel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 title description 30
- 238000004519 manufacturing process Methods 0.000 title description 5
- 239000000203 mixture Substances 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 11
- 239000002245 particle Substances 0.000 claims description 11
- 238000003754 machining Methods 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 6
- 238000000465 moulding Methods 0.000 claims description 5
- 238000005245 sintering Methods 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 description 13
- 229910052751 metal Inorganic materials 0.000 description 8
- 239000002184 metal Substances 0.000 description 8
- 239000011230 binding agent Substances 0.000 description 7
- 235000021355 Stearic acid Nutrition 0.000 description 4
- 239000002131 composite material Substances 0.000 description 4
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 4
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 4
- 239000008117 stearic acid Substances 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000010276 construction Methods 0.000 description 2
- PCLIRWBVOVZTOK-UHFFFAOYSA-M 2-(1-methylpyrrolidin-1-ium-1-yl)ethyl 2-hydroxy-2,2-diphenylacetate;iodide Chemical compound [I-].C=1C=CC=CC=1C(O)(C=1C=CC=CC=1)C(=O)OCC[N+]1(C)CCCC1 PCLIRWBVOVZTOK-UHFFFAOYSA-M 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000008240 homogeneous mixture Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- BDAGIHXWWSANSR-NJFSPNSNSA-N hydroxyformaldehyde Chemical compound O[14CH]=O BDAGIHXWWSANSR-NJFSPNSNSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 229910000018 strontium carbonate Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J23/00—Details of transit-time tubes of the types covered by group H01J25/00
- H01J23/02—Electrodes; Magnetic control means; Screens
- H01J23/04—Cathodes
- H01J23/05—Cathodes having a cylindrical emissive surface, e.g. cathodes for magnetrons
Definitions
- FIG.2 METHOD OF MAKING NICKEL SPONGE CATHODES Filed Jan. 10, 1946 FIG.2
- Sparking can be loose1y defined as the boilin of cathode material to the anode.
- the impe cathode sleeve and of the coatin 3 oh the sparking may possibly be due to e of, or a combination of, the following:
- her object to constr rial can be impregnated.
- This homogeneous mixture was pressed into a steel collar-shaped die or mold, labeled Ill on the accompanying drawings, which die is fitted onto object to construct a cathode supporting nickel sleeve II, this sleeve becoming part of the finished cathode structure.
- the metal chosen for the sleeve is the same as that used for the mixture to avoid, among Other things, trouble arising from different coefficients of expansion.
- the mixture is fired in a hydrogen furnace to volatilize the stearic acid and to sinter the flat nickel flakes together and to the nickel sleeve. Die IE is then removed to leave the sintered structure forming a porous metal collar on sleeve l I.
- the sintcred structure as seen underv a low power microscope, consists of layers of the flat nickel flakes l2 tightly bonded together as shown in Fig. 2.
- the discontinuities-in. the arrangemerit of the flakes, as shown atlitof Fig. 2 are eliminated by machining the sintered structure to a desirable thickness.
- the thickness of the porous structure after the mold was removed was approximately .020
- the porous structure has a large free volume and a large interracial area, resulting in high electrical and thermal conductivity.
- the use of the fiat nickel flakes allows for a larger interfacial area of contact between metal and coating.
- 11 similarly porous structure can be prepared by utilizing flakes which'have random shapes, and the volatile binder may be omitted. These changes of method are made, however, at a sacriflce of interfacial area;
- the porous structure so prepared is impregnated with the ordinarily used alkaline earth carbonates such as barium, calcium, or a strontium carbonate, the coating being-applied with a brush in the present case, and heat-treated as a conventional cathode.
- alkaline earth carbonates such as barium, calcium, or a strontium carbonate
- the method of constructing a cathode which method includes-mixing particles of metal with a volatile binder molding the mixture to form a hollow tube fitted onto a supporting sleeve, holding the molded mixture in contact with the sleeve while heating the mixture thereby removing the volatile substance and sintering said particles or metal together and to said supporting sleeve, machining the outer surface of the composite structure so formed to remove discontinuities in the arrangement of particles, impregnating the composite structure so prepared with an alkaline earth carbonate, and heating until predetermined emission characteristics are obtained.
- the method of constructing a base structure for a cathode including the steps of mixing particles of metal with a mouldable, volatile binder, molding the mixture to form a molded hollow tube fitted onto a metallic sleeve, heating said mixture while supported in intimate contact with said sleeve thereby. removing the volatile binder and sintering said particles of metal together and to said metallic sleeve, and machining the outer surface of the base structure so formed to remove the outermost layer of particles.
- the method of constructing a base structure for a cathode including the steps of mixing flat flakes of nickel or 100-200 mesh size with stearic acid, pressing the mixture into a collar-shaped mould fitted onto the supporting sleeve to give a thickness of the mixture of approximately .020 inch on said sleeve, heating said mixture with said mould in place thereby removing the stearic acid, sintering said nickel flakes together and to said supporting sleeve with said mould in place, and machining said sintered nickel flakes with said mould removed to leave a thickness of approximately .010 inch of sintered flakes on said supporting sleeve.
- the method of manufacturing a cathode comprising the steps of mixing flat flakes of metalwitha volatile binder, molding the mixture to form a hollow tube covering a metallic sleeve, supporting the molded mixture in place while heatingthe tube and sleeve to remove the volatile binder and to sinter the metallic flakes togethcr and to said supporting sleeve, machining said composite structure to remove particles at the outer surface, and impregnating the machined structure with an electron emitting material.
- the method of producing a porous nickel base structure for a cathode comprising the steps of mixing flat flakes of nickel powder with stearic acid, the proportions being determined by the desired free volume in the final porous structure, molding the mixture to form a hollow tube covering a nickel sleeve, supporting the molded m'ixture in place while heating the tube and sleeve to remove the volatile binder and to sinter the nickel flakes together and to said nickel sleeve, and machining said composite structure to remove particles at the outer surface.
Description
IN My y 11, 1954 J. G. BUCK 2,677,873
METHOD OF MAKING NICKEL SPONGE CATHODES Filed Jan. 10, 1946 FIG.2
INVENTOR JAMES G. BUCK ATTORNEY Patented May 11, 1954 UNITED STATES TENT OFFICE METHOD OF MAKING NI CATHODE James G. Buck, Meriden,
assignments, to the Un as represented by the This invention relate tubes, and more particu of cathodes therein.
Considerable research ha production or" cathod and with long life un s to electronic vacuum larly to the construction s been done on the es which will operate stably der pulsed operation in magnsmitting tubes.
pulsed performance.
One of the principal requiremen magnetron cathode is that it have good sparking properties. Sparking can be loose1y defined as the boilin of cathode material to the anode.
ts for a pulsed a prescribed Improvement are: (1) the impe cathode sleeve and of the coatin 3 oh the sparking may possibly be due to e of, or a combination of, the following:
electron path means drop, with a resulting discharge similar to that of a dielectric breakdown It is questionable whether the mechanism involved in (1) and (2) immediately above are actually difierent. In any event, concern is with the cause and not the method.
Of the several impedances it appears that. 86
N. H., assignor,
Secretary of Application January 10, 1946, Serial No.
5 Claims. (Cl.
SCKEL SPONGE by mesne of America the Navy ited States when the cathode is sub tion, the impedance at the interface of the oathode sleeve and its coating is most important.
his interfaci jected to pulsed operaover, the heat dis ture are improved It is, accordingly, the object of the present invention to improve the physical structure of cathodes.
It is another which will have good sparking properties.
her object to constr rial can be impregnated.
In the present embodiment sisting of flat flakes of nickel powder con- 200 mesh size was substituted for being non-criti the nickel, cal. Similarly, inder, the ments being that it b due, and has a high 111 principal requiree volatile, will leave no resielting point. r
This homogeneous mixture was pressed into a steel collar-shaped die or mold, labeled Ill on the accompanying drawings, which die is fitted onto object to construct a cathode supporting nickel sleeve II, this sleeve becoming part of the finished cathode structure. The metal chosen for the sleeve is the same as that used for the mixture to avoid, among Other things, trouble arising from different coefficients of expansion. The mixture is fired in a hydrogen furnace to volatilize the stearic acid and to sinter the flat nickel flakes together and to the nickel sleeve. Die IE is then removed to leave the sintered structure forming a porous metal collar on sleeve l I.
The sintcred structure, as seen underv a low power microscope, consists of layers of the flat nickel flakes l2 tightly bonded together as shown in Fig. 2. The discontinuities-in. the arrangemerit of the flakes, as shown atlitof Fig. 2 are eliminated by machining the sintered structure to a desirable thickness. In the present embodiment the thickness of the porous structure after the mold was removed was approximately .020
inch, this being machined down to .010 inch in the final product.
The porous structure has a large free volume and a large interracial area, resulting in high electrical and thermal conductivity. The use of the fiat nickel flakes allows for a larger interfacial area of contact between metal and coating. 11 similarly porous structure can be prepared by utilizing flakes which'have random shapes, and the volatile binder may be omitted. These changes of method are made, however, at a sacriflce of interfacial area;
The porous structure so prepared is impregnated with the ordinarily used alkaline earth carbonates such as barium, calcium, or a strontium carbonate, the coating being-applied with a brush in the present case, and heat-treated as a conventional cathode.
In summary, the novel features, as sought to be outlined in the following claims, are the construction of a porous metal sponge having a larger interracial area than the previously used screen type of cathode. The structure, there-- fore, provides for higher electrical andv thermal conductivity, with resulting sparking properties which are more desirable for pulsed operation.
What is claimed is:
1. The method of constructing a cathode, which method includes-mixing particles of metal with a volatile binder molding the mixture to form a hollow tube fitted onto a supporting sleeve, holding the molded mixture in contact with the sleeve while heating the mixture thereby removing the volatile substance and sintering said particles or metal together and to said supporting sleeve, machining the outer surface of the composite structure so formed to remove discontinuities in the arrangement of particles, impregnating the composite structure so prepared with an alkaline earth carbonate, and heating until predetermined emission characteristics are obtained.
2. The method of constructing a base structure for a cathode, said method including the steps of mixing particles of metal with a mouldable, volatile binder, molding the mixture to form a molded hollow tube fitted onto a metallic sleeve, heating said mixture while supported in intimate contact with said sleeve thereby. removing the volatile binder and sintering said particles of metal together and to said metallic sleeve, and machining the outer surface of the base structure so formed to remove the outermost layer of particles.
3. The method of constructing a base structure for a cathode, said method including the steps of mixing flat flakes of nickel or 100-200 mesh size with stearic acid, pressing the mixture into a collar-shaped mould fitted onto the supporting sleeve to give a thickness of the mixture of approximately .020 inch on said sleeve, heating said mixture with said mould in place thereby removing the stearic acid, sintering said nickel flakes together and to said supporting sleeve with said mould in place, and machining said sintered nickel flakes with said mould removed to leave a thickness of approximately .010 inch of sintered flakes on said supporting sleeve.
l. The method of manufacturing a cathode comprising the steps of mixing flat flakes of metalwitha volatile binder, molding the mixture to form a hollow tube covering a metallic sleeve, supporting the molded mixture in place while heatingthe tube and sleeve to remove the volatile binder and to sinter the metallic flakes togethcr and to said supporting sleeve, machining said composite structure to remove particles at the outer surface, and impregnating the machined structure with an electron emitting material.
5. The method of producing a porous nickel base structure for a cathode comprising the steps of mixing flat flakes of nickel powder with stearic acid, the proportions being determined by the desired free volume in the final porous structure, molding the mixture to form a hollow tube covering a nickel sleeve, supporting the molded m'ixture in place while heating the tube and sleeve to remove the volatile binder and to sinter the nickel flakes together and to said nickel sleeve, and machining said composite structure to remove particles at the outer surface.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,051,814 Lowendahl Jan. 28, 1913 1,902,478 Wiegand Mar. 21, 1933 2,172,207 Kolligs Sept. 5, 1939 2,289,658 Koehring July 14, 1942 2,337,588 Calkins I Dec. 28, 1943
Claims (1)
- 2. THE METHOD OF CONSTRUCTING A BASE STRUCTURE FOR A CATHODE, SAID METHOD INCLUDING THE STEPS OF MIXING PARTICLES OF METAL WITH A MOULDABLE, VOLATILE BINDER, MOLDING THE MIXTURE TO FORM A MOLDED HOLLOW TUBE FITTED ONTO A METALLIC SLEEVE, HEATING SAID MIXTURE WHILE SUPPORTED IN INTIMATE CONTACT WITH SAID SLEEVE THEREBY REMOVING THE VOLATILE BINDER AND SINTERING SAID PARTICLES OF METAL TOGETHER AND TO SAID METALLIC SLEEVE, AND MACHINING THE OUTER SURFACE OF THE BASE STRUCTURE SO FORMED TO REMOVE THE OUTERMOST LAYER OF PARTICLES.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US640277A US2677873A (en) | 1946-01-10 | 1946-01-10 | Method of making nickel sponge cathodes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US640277A US2677873A (en) | 1946-01-10 | 1946-01-10 | Method of making nickel sponge cathodes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2677873A true US2677873A (en) | 1954-05-11 |
Family
ID=24567584
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US640277A Expired - Lifetime US2677873A (en) | 1946-01-10 | 1946-01-10 | Method of making nickel sponge cathodes |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2677873A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3010826A (en) * | 1951-03-22 | 1961-11-28 | Philips Corp | Method of making dispenser type cathodes |
| US3076915A (en) * | 1954-12-24 | 1963-02-05 | Egyesuelt Izzolampa | Cathode assembly and method of making same |
| US3128531A (en) * | 1959-10-22 | 1964-04-14 | Nat Res Dev | Dynodes for electron discharge tubes and methods of making same |
| US3184636A (en) * | 1961-06-15 | 1965-05-18 | Sylvania Electric Prod | Cold cathode |
| US3226806A (en) * | 1960-03-18 | 1966-01-04 | Eitel Mccullough Inc | Method of making a cathode heater assembly |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1051814A (en) * | 1909-11-11 | 1913-01-28 | Victor Loewendahl | Process of manufacturing porous metal blocks. |
| US1902814A (en) * | 1930-08-25 | 1933-03-28 | Crowther Frederick Kenneth | Recording of sounds |
| US2172207A (en) * | 1936-09-19 | 1939-09-05 | Siemens Ag | Glow cathode |
| US2289658A (en) * | 1939-05-01 | 1942-07-14 | Gen Motors Corp | Method of making composite metal elements |
| US2337588A (en) * | 1939-11-10 | 1943-12-28 | Chrysler Corp | Composite porous metal article |
-
1946
- 1946-01-10 US US640277A patent/US2677873A/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1051814A (en) * | 1909-11-11 | 1913-01-28 | Victor Loewendahl | Process of manufacturing porous metal blocks. |
| US1902814A (en) * | 1930-08-25 | 1933-03-28 | Crowther Frederick Kenneth | Recording of sounds |
| US2172207A (en) * | 1936-09-19 | 1939-09-05 | Siemens Ag | Glow cathode |
| US2289658A (en) * | 1939-05-01 | 1942-07-14 | Gen Motors Corp | Method of making composite metal elements |
| US2337588A (en) * | 1939-11-10 | 1943-12-28 | Chrysler Corp | Composite porous metal article |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3010826A (en) * | 1951-03-22 | 1961-11-28 | Philips Corp | Method of making dispenser type cathodes |
| US3076915A (en) * | 1954-12-24 | 1963-02-05 | Egyesuelt Izzolampa | Cathode assembly and method of making same |
| US3128531A (en) * | 1959-10-22 | 1964-04-14 | Nat Res Dev | Dynodes for electron discharge tubes and methods of making same |
| US3226806A (en) * | 1960-03-18 | 1966-01-04 | Eitel Mccullough Inc | Method of making a cathode heater assembly |
| US3184636A (en) * | 1961-06-15 | 1965-05-18 | Sylvania Electric Prod | Cold cathode |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US2543728A (en) | Incandescible cathode | |
| US2912611A (en) | Thermionic cathodes | |
| US4518890A (en) | Impregnated cathode | |
| US2488731A (en) | Electron-emitting electrode for electric discharge tubes | |
| US2677873A (en) | Method of making nickel sponge cathodes | |
| US2619706A (en) | Electrode for electric discharge devices | |
| US3879830A (en) | Cathode for electron discharge device having highly adherent emissive coating of nickel and nickel coated carbonates | |
| US2447038A (en) | Cathode structure | |
| US4982133A (en) | Dispenser cathode and manufacturing method therefor | |
| US2858470A (en) | Cathode for electron discharge devices | |
| US3015560A (en) | Method of fabricating cathode for electron discharge devices | |
| US3238596A (en) | Method of fabricating a matrix cathode | |
| KR920003185B1 (en) | Dispensor cathode and the manufacturing method of the same | |
| US2995674A (en) | Impregnated cathodes | |
| JPS59169034A (en) | Matrix cathode and its manufacture | |
| US2123686A (en) | Tubular cathode for electron discharge devices | |
| US1980675A (en) | Method and means for preventing heater-cathode leakage in a radio tube | |
| US2585534A (en) | Secondary electron emissive electrode and its method of making | |
| US3710161A (en) | Quick-heating impregnated planar cathode | |
| US1851699A (en) | Space-current discharge device | |
| US3722045A (en) | Methods of improving adherence of emissive material in thermionic cathodes | |
| US2757308A (en) | Emissive cathode | |
| US3441781A (en) | Microwave tube cathode of the bariumcalcium aluminate type | |
| JP3720913B2 (en) | Impregnated cathode structure, cathode substrate used therefor, and electron tube using the same | |
| US2538873A (en) | Electric discharge tube |