GB726032A - Improvements in or relating to the manufacture of porous sintered metal elements - Google Patents

Improvements in or relating to the manufacture of porous sintered metal elements

Info

Publication number
GB726032A
GB726032A GB17362/53A GB1736253A GB726032A GB 726032 A GB726032 A GB 726032A GB 17362/53 A GB17362/53 A GB 17362/53A GB 1736253 A GB1736253 A GB 1736253A GB 726032 A GB726032 A GB 726032A
Authority
GB
United Kingdom
Prior art keywords
plug
temperature
refractory metal
type cathode
dispenser
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
GB17362/53A
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 GB726032A publication Critical patent/GB726032A/en
Expired legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/11—Making porous workpieces or articles
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C1/00—Making non-ferrous alloys
    • C22C1/08—Alloys with open or closed pores
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Powder Metallurgy (AREA)
  • Solid Thermionic Cathode (AREA)

Abstract

726,032. Powder metallurgy. PHILIPS ELECTRICAL INDUSTRIES, Ltd. June 23, 1953 [June 26, 1952], No. 17362/53. Classes 83 (2) and 83 (4). A method of making a porous sintered refractory metal member, preferably for use in a dispenser type cathode comprises forming a body of refractory metal powder, sintering the body, mechanically shaping the body to the required shape, oxidizing the surface of the body to a depth at least equal to the layer of glaze formed thereon by the shaping operation, and heating the oxidized body in a reducing atmosphere at a temperature at which the oxides are reduced to metal and the refractory metal is recrystallized. A porous plug 4 for a dispenser type cathode 1 is formed by pressing a powder of tungsten, molybdenum, tantalum, titanium or hafnium into a bar at a pressure of about 2000 kg./sq. cm. and sintering at 2200‹ to 2400‹ C. The bar is then swaged to size and cut into a plurality of plugs. Due to the swaging and cutting, a metallic sheen or glaze is formed on the surface of the plug and this reduces the porosity. The surface is then oxidized by heating the plug in air or in an atmosphere containing a large proportion of oxygen at temperature of about 1000‹ C. for about one minute. The plugs are then heated in a hydrogen or hydrogen-nitrogen atmosphere at a temperature of about 1000‹ C. to reduce the oxides and this restores the porosity to its desired value. In the manufacture of a dispenser-type cathode, the plug 4 is welded to a cylindrical tube 2 of molybdenum. Specification 641,581, [Group XL (a)], is referred to.
GB17362/53A 1952-06-26 1953-06-23 Improvements in or relating to the manufacture of porous sintered metal elements Expired GB726032A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US318054XA 1952-06-26 1952-06-26

Publications (1)

Publication Number Publication Date
GB726032A true GB726032A (en) 1955-03-16

Family

ID=21861485

Family Applications (1)

Application Number Title Priority Date Filing Date
GB17362/53A Expired GB726032A (en) 1952-06-26 1953-06-23 Improvements in or relating to the manufacture of porous sintered metal elements

Country Status (5)

Country Link
BE (1) BE520936A (en)
CH (1) CH318054A (en)
FR (1) FR1079579A (en)
GB (1) GB726032A (en)
NL (1) NL81847C (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110193601A (en) * 2019-06-13 2019-09-03 金堆城钼业股份有限公司 A kind of preparation method of bilayer or multilayer refractory metal composite pipe

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110193601A (en) * 2019-06-13 2019-09-03 金堆城钼业股份有限公司 A kind of preparation method of bilayer or multilayer refractory metal composite pipe

Also Published As

Publication number Publication date
NL81847C (en)
BE520936A (en)
FR1079579A (en) 1954-12-01
CH318054A (en) 1956-12-15

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