GB919419A - Improvements in or relating to impregnated cathodes suitable for use in electric discharge tubes - Google Patents

Improvements in or relating to impregnated cathodes suitable for use in electric discharge tubes

Info

Publication number
GB919419A
GB919419A GB208260A GB208260A GB919419A GB 919419 A GB919419 A GB 919419A GB 208260 A GB208260 A GB 208260A GB 208260 A GB208260 A GB 208260A GB 919419 A GB919419 A GB 919419A
Authority
GB
United Kingdom
Prior art keywords
carbon
layer
carbide
carbonized
tungsten
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
GB208260A
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.)
Philips Electrical Industries Ltd
Original Assignee
Philips Electrical Industries Ltd
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 Electrical Industries Ltd filed Critical Philips Electrical Industries Ltd
Publication of GB919419A publication Critical patent/GB919419A/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
    • 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
    • H01J9/042—Manufacture, activation of the emissive part
    • H01J9/047—Cathodes having impregnated bodies
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249955—Void-containing component partially impregnated with adjacent component

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Solid Thermionic Cathode (AREA)

Abstract

919,419. Cathode materials and processing. PHILIPS ELECTRICAL INDUSTRIES Ltd. Jan. 20, 1960 [Jan. 23, 1959], No. 2082/60. Class 39 (1). In a method of making an impregnated cathode, at least part of the surface of a porous refractory body 10 is carbonized or provided with a layer of carbon and the body is impregnated through the resulting carbide or carbon layer 15 with pre-molten barium aluminate. The body 10 is afterwards incorporated into a cathode structure 17, at least part of its surface being free of carbon and carbide to constitute a high-emission area 12. Non-porous parts of the cathode structure, e.g. molybdenum cylinder 17, may also be carbonized to reduce emission therefrom. Carbonization of porous body 10, which may be of tungsten, or a tungsten-molybdenum alloy, or a tantalum-molybdenum alloy, may be effected by embedding it in carbon or graphite powder and heating to a temperature of 1200‹ to 1700‹ C. for 5 to 15 minutes to form a carbide layer 10 to 40 microns thick, the area 12 being protected against carbonization by a templet or having its carbide coating removed afterwards by mechanical treatment or by heating alternately in a reducing and in an oxidizing atmosphere. Alternatively, a layer of carbide may be sprayed or painted on to the surface of body 10 and caused to adhere thereto by sintering, or the porous body may be heated in naphthalene vapour. As a further alternative a layer of carbon or graphite powder or a compound such as sugar, which decomposes to carbon on heating, may be used, the layer of carbon being brushed off after impregnation, a protective layer of tungsten, which may have been provided on the high emission areas, also being removed. A composite porous body can also be formed by welding together carbonized and non-carbonized parts. A specific example is given.
GB208260A 1959-01-23 1960-01-20 Improvements in or relating to impregnated cathodes suitable for use in electric discharge tubes Expired GB919419A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US78860359 US2972078A (en) 1959-01-23 1959-01-23 Carburization of dispenser cathodes

Publications (1)

Publication Number Publication Date
GB919419A true GB919419A (en) 1963-02-27

Family

ID=25144990

Family Applications (1)

Application Number Title Priority Date Filing Date
GB208260A Expired GB919419A (en) 1959-01-23 1960-01-20 Improvements in or relating to impregnated cathodes suitable for use in electric discharge tubes

Country Status (9)

Country Link
US (1) US2972078A (en)
AT (1) AT219166B (en)
BE (1) BE586842A (en)
CH (1) CH402197A (en)
DE (1) DE1094887B (en)
DK (1) DK93307C (en)
FR (1) FR1245997A (en)
GB (1) GB919419A (en)
NL (1) NL108689C (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2225158A (en) * 1988-11-12 1990-05-23 Samsung Electronic Devices Manufacturing dispenser cathodes of electron guns

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2242986C3 (en) * 1972-09-01 1981-05-07 Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe Hot cathode
DE2842079A1 (en) * 1978-09-27 1980-04-03 Siemens Ag SUPPLY CATHODE, ESPECIALLY METAL CAPILLARY CATHODE
GB2100502B (en) * 1978-11-30 1983-08-03 Varian Associates Dispenser cathodes
DE3334971A1 (en) * 1983-09-27 1985-04-18 Siemens AG, 1000 Berlin und 8000 München Dispenser cathode, in particular capillary metal cathode
KR920003185B1 (en) * 1990-01-31 1992-04-23 삼성전관 주식회사 Dispensor cathode and the manufacturing method of the same
FR2803088B1 (en) * 1999-12-22 2002-02-01 Thomson Tubes & Displays METHOD FOR ASSEMBLING A CATHODE FOR A CATHODE RAY TUBE

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1922244A (en) * 1930-09-13 1933-08-15 Fansteel Prod Co Inc Electrode and method of making the same
BE509019A (en) * 1951-02-08
CH305546A (en) * 1951-02-16 1955-02-28 Siemens Ag Cathode for electrical discharge vessels.

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2225158A (en) * 1988-11-12 1990-05-23 Samsung Electronic Devices Manufacturing dispenser cathodes of electron guns
GB2225158B (en) * 1988-11-12 1993-01-13 Samsung Electronic Devices Manufacturing method for dispenser cathode of an electron gun

Also Published As

Publication number Publication date
DK93307C (en) 1962-04-30
DE1094887B (en) 1960-12-15
CH402197A (en) 1965-11-15
BE586842A (en) 1960-07-22
AT219166B (en) 1962-01-10
US2972078A (en) 1961-02-14
FR1245997A (en) 1960-11-10
NL108689C (en) 1900-01-01

Similar Documents

Publication Publication Date Title
EP0179513B1 (en) Method of manufacturing a scandate dispenser cathode and dispenser cathode manufactured by means of the method
CA2037675A1 (en) Electron tube cathode
US3120453A (en) Porous carbonaceous body with sealed surface for use as arc-furnace electrode or structural component of nuclear reactors
GB919419A (en) Improvements in or relating to impregnated cathodes suitable for use in electric discharge tubes
US3396054A (en) Method and apparatus for metallic impregnation of carbon and graphite
US3454816A (en) Indirectly heated dispenser cathode for electric discharge tube
US2417730A (en) Electron tube and method of making same
US2250986A (en) Vacuum-tight metal-to-ceramic seal and method of making same
US2659685A (en) Boride cathodes
US3299326A (en) Solid electrolytic capacitor with porous sintered electrode of thermally pretreated anodizable metal particles
US2693431A (en) Method of making electron emitters
US2936250A (en) Cemented zirconium boride material having a protective chromium containing coating
US1916410A (en) Alloy
US2899299A (en) Method of manufacturing sintered
US1948445A (en) Electron emitting body and the process for its manufacture
US2352137A (en) Electron emitting element
US3041210A (en) Method of making cold cathodes for vacuum tubes and article
JPS5659422A (en) Field emissive cathode
US1747061A (en) Electrode composition for electron-discharge devices
JPS60177528A (en) Tantalum filament excellent in durability and its manufacture
GB924595A (en) Method of manufacturing cathodes
US2160583A (en) Pool-type discharge device
JPS643350B2 (en)
JPS57119436A (en) Impregnated type cathode
US1747064A (en) Electrode composition for electron-discharge devices