ES342176A1 - Dispenser cathode made of tungsten powder having a grain size of less than three microns - Google Patents

Dispenser cathode made of tungsten powder having a grain size of less than three microns

Info

Publication number
ES342176A1
ES342176A1 ES342176A ES342176A ES342176A1 ES 342176 A1 ES342176 A1 ES 342176A1 ES 342176 A ES342176 A ES 342176A ES 342176 A ES342176 A ES 342176A ES 342176 A1 ES342176 A1 ES 342176A1
Authority
ES
Spain
Prior art keywords
mixture
powder
slurry
tungsten
less
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
Application number
ES342176A
Other languages
Spanish (es)
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Publication of ES342176A1 publication Critical patent/ES342176A1/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/13—Solid thermionic cathodes
    • H01J1/20—Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment
    • H01J1/28—Dispenser-type cathodes, e.g. L-cathode

Landscapes

  • Solid Thermionic Cathode (AREA)
  • Powder Metallurgy (AREA)

Abstract

A dispenser cathode emissive body is manufactured by preparing a homogeneous mixture of barium carbonate, calcium carbonate and aluminium oxide by co-precipitation from a single solution, making a slurry of the mixture and a soluble organic compound, e.g. sucrose, drying the slurry and grinding the dried slurry to form a powder, mixing the powder with a tungsten powder having a maximum particle size of less than 3 Á, then pressing the tungstencontaining mixture using a pressure of at least 20,000 kgm/sq. cm. to form a body and finally heating the body to degas the material and convert the co-precipitated mixture into an aluminate and to form a sintered body. In addition the co-precipitated mixture may be dried and the slurry prepared using a solution of the soluble organic compound. In an example the tungsten-containing mixture comprises 93% by weight W powder of particle size less than 0À5 Á, 0À2% by weight sucrose and 6À8% by weight of co-precipitated BaCO 3 , CaCO 3 and Al 2 O 3 in molar ratio of 5: 3: 2 respectively, and a pressure of at least 25,000 kgm/sq. cm. is used. The very fine tungsten particles may be prepared by the reduction of gaseous tungsten chloride with hydrogen.
ES342176A 1966-06-24 1967-06-22 Dispenser cathode made of tungsten powder having a grain size of less than three microns Expired ES342176A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL6608782A NL6608782A (en) 1966-06-24 1966-06-24

Publications (1)

Publication Number Publication Date
ES342176A1 true ES342176A1 (en) 1968-10-01

Family

ID=19796967

Family Applications (2)

Application Number Title Priority Date Filing Date
ES342176A Expired ES342176A1 (en) 1966-06-24 1967-06-22 Dispenser cathode made of tungsten powder having a grain size of less than three microns
ES353888A Expired ES353888A1 (en) 1966-06-24 1968-05-14 Dispenser cathode made of tungsten powder having a grain size of less than three microns

Family Applications After (1)

Application Number Title Priority Date Filing Date
ES353888A Expired ES353888A1 (en) 1966-06-24 1968-05-14 Dispenser cathode made of tungsten powder having a grain size of less than three microns

Country Status (8)

Country Link
US (1) US3458749A (en)
AT (1) AT270820B (en)
BE (1) BE700464A (en)
CH (1) CH489111A (en)
ES (2) ES342176A1 (en)
GB (1) GB1131586A (en)
NL (1) NL6608782A (en)
SE (1) SE318031B (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3534455A (en) * 1968-05-03 1970-10-20 Us Army Method of making thermionic cathodes
US3656020A (en) * 1970-11-18 1972-04-11 Spectra Mat Inc Thermionic cathode comprising mixture of barium oxide, calcium oxide and lithium oxide
US3760218A (en) * 1972-04-10 1973-09-18 Spectramat Inc Thermionic cathode
JPS5046058U (en) * 1973-08-27 1975-05-08
JPS5150955U (en) * 1974-10-16 1976-04-17
US4837480A (en) * 1988-03-28 1989-06-06 Hughes Aircraft Company Simplified process for fabricating dispenser cathodes
US5092805A (en) * 1988-11-11 1992-03-03 Samsung Electron Devices Co., Ltd. Manufacturing method for dispenser code
KR930014673A (en) * 1991-12-20 1993-07-23 김정배 Impregnated Cathode Structure and Manufacturing Method Thereof
US7406268B2 (en) * 2003-08-27 2008-07-29 Avago Technologies Limited Optical receiver circuit

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL97850C (en) * 1953-08-14
US2975320A (en) * 1958-12-03 1961-03-14 Rca Corp Low-temperature plasma source
US3076916A (en) * 1959-01-21 1963-02-05 Semicon Associates Inc Impregnated tungsten cathode structures and methods for fabricating same

Also Published As

Publication number Publication date
AT270820B (en) 1969-05-12
SE318031B (en) 1969-12-01
DE1614256A1 (en) 1970-05-27
BE700464A (en) 1967-12-27
US3458749A (en) 1969-07-29
DE1614256B2 (en) 1975-09-11
CH489111A (en) 1970-04-15
GB1131586A (en) 1968-10-23
ES353888A1 (en) 1969-10-01
NL6608782A (en) 1967-12-27

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