GB1078754A - Improvements in and relating to porous metal bodies - Google Patents

Improvements in and relating to porous metal bodies

Info

Publication number
GB1078754A
GB1078754A GB3999864A GB3999864A GB1078754A GB 1078754 A GB1078754 A GB 1078754A GB 3999864 A GB3999864 A GB 3999864A GB 3999864 A GB3999864 A GB 3999864A GB 1078754 A GB1078754 A GB 1078754A
Authority
GB
United Kingdom
Prior art keywords
microns
tungsten
fine
sintered
layer
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
GB3999864A
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 Electronics UK Ltd
Original Assignee
Philips Electronic and Associated 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 Electronic and Associated Industries Ltd filed Critical Philips Electronic and Associated Industries Ltd
Publication of GB1078754A publication Critical patent/GB1078754A/en
Expired legal-status Critical Current

Links

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
    • H01J9/042—Manufacture, activation of the emissive part
    • 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
    • H01J27/00—Ion beam tubes
    • H01J27/02—Ion sources; Ion guns
    • H01J27/26—Ion sources; Ion guns using surface ionisation, e.g. field effect ion sources, thermionic ion sources

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Powder Metallurgy (AREA)

Abstract

An emissive member of a thermionic ion source or of a thermionic cathode consists of a porous metal body the major portion of which has large pores which prevent distortion at operating temperature, and an emissive surface portion formed by a thin layer of fine porosity with a pore density between 1 million and 10 million per sq. cm. In an example tungsten powder particle size 1 to 6 microns is compacted and sintered at 2100 DEG C. in a neutral or reducing atmosphere to form a sintered body with grains of 3 to 20 microns and a pore size of 1 to 12 microns. The sintered tungsten may be impregnated with copper to aid machining, the copper then being evaporated. A fine pored emissive layer of tungsten is then applied to the sintered body as a suspension of tungsten particle size 0.5 to 1 microns in amyl acetate and collodion. Sintering in hydrogen at 1800 DEG C. produces a fine porous layer of 20 micron thick, particle size 0.5 to 6 microns and pore size 1 to 3 microns. The surface of the sintered tungsten may be oxidized by heating in air at 500 DEG C. before applying the fine layer. In an alternative method the fine layer may be formed by applying a suspension of tungsten trioxide which is reduced in situ during sintering. The sintered tungsten coarse pored body may be impregnated with an alkaline earth metal compound prior to the application of the fine layer.
GB3999864A 1963-10-04 1964-10-01 Improvements in and relating to porous metal bodies Expired GB1078754A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US31385963A 1963-10-04 1963-10-04

Publications (1)

Publication Number Publication Date
GB1078754A true GB1078754A (en) 1967-08-09

Family

ID=23217458

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3999864A Expired GB1078754A (en) 1963-10-04 1964-10-01 Improvements in and relating to porous metal bodies

Country Status (2)

Country Link
DE (1) DE1213059B (en)
GB (1) GB1078754A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2839318A1 (en) * 2002-05-06 2003-11-07 Agency Defense Dev PROCESS FOR APPLYING A THIN FILM OF TUNGSTEN USING TUNGSTENE OXIDE POWDER
AT506340B1 (en) * 2008-01-25 2012-04-15 Fotec Forschungs & Technologi METHOD FOR PRODUCING AN ION SOURCE

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2839318A1 (en) * 2002-05-06 2003-11-07 Agency Defense Dev PROCESS FOR APPLYING A THIN FILM OF TUNGSTEN USING TUNGSTENE OXIDE POWDER
AT506340B1 (en) * 2008-01-25 2012-04-15 Fotec Forschungs & Technologi METHOD FOR PRODUCING AN ION SOURCE

Also Published As

Publication number Publication date
DE1213059B (en) 1966-03-24

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