US2214902A - Method of producing cathode materials - Google Patents

Method of producing cathode materials Download PDF

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Publication number
US2214902A
US2214902A US311136A US31113639A US2214902A US 2214902 A US2214902 A US 2214902A US 311136 A US311136 A US 311136A US 31113639 A US31113639 A US 31113639A US 2214902 A US2214902 A US 2214902A
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US
United States
Prior art keywords
thorium
cathode materials
rhenium
producing cathode
producing
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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
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US311136A
Inventor
Herriger Felix
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.)
Alcatel Lucent Deutschland AG
C Lorenz AG
Original Assignee
Standard Elektrik Lorenz AG
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Publication of US2214902A publication Critical patent/US2214902A/en
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Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00Apparatus 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
    • H01J9/02Manufacture of electrodes or electrode systems
    • H01J9/04Manufacture of electrodes or electrode systems of thermionic cathodes
    • H01J9/042Manufacture, activation of the emissive part

Definitions

  • This invention relates to methods of producing cathode materials and consists in certain features of novelty which will be readily understood from the following and be pointed out in the ap- 5 pended claims.
  • the rhenium does not form any carbide, it involves such high absorption properties with respect to thorium that no appreciable evaporation of the thorium from its superficies will take place at normal operating temperatures of say 1800 degrees centigrade.
  • thoriated rhenium cath- 5 odes The manufacture of thoriated rhenium cath- 5 odes is similar to that of thoriated tungsten cathodes.
  • the method of producing cathode materials which comprises mixing metallic rhenium pow- 15 der and an additional amount up to 10 per cent of pulverized thorium oxide, compressing the resulting mixture at high pressure, and sintering the compressed compound in a protective gaseous atmosphere.
  • the method of producing cathodes for electron discharge devices which comprises mixing metallic rhenium powder and an additional amount of up to 10-per cent of pulverized thorium oxide, compressing this mixture at high pressure, sintering the compressed compound in a protective gaseous atmosphere, and hammering the resulting blocks to the desirable shape and size.
  • a cathode for electron discharge devices consisting of rhenium and an additional amount of up to 10 per cent of thorium.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Discharge Lamp (AREA)

Description

Patented Sept. 17, 1940 METHOD OF PRODUCING CATHODE MATERIALS Felix Herriger, Berlin, Germany, assignor to G. Lorenz Aktiengesellschaft, Berlin-Tempelhof,
Germany, a company No Drawing. Application December 27, 1939, Se-
rial No. 311,136. In Germany December 2,
3 Claims.
This invention relates to methods of producing cathode materials and consists in certain features of novelty which will be readily understood from the following and be pointed out in the ap- 5 pended claims.
It is a known fact that the electron emissive performance of thoriated tungsten cathodes on account of the absorbed mono-atomic molecular layer of thorium is lower than if the cathode is made of pure tungsten. It is also familiar to those skilled in the art that even thoriated tantalum cathodes do not give any increase with respect to the electron emission performance since the two elements thorium and tantalum are classified in the same group or family of the periodic system, from which follows that the dipole momentum, which inherently contributes toward a reduction of the electron emission performance, assumes a very low value.
Careful investigations made by applicant have proven that the dipole momentum still-may be increased. This is accomplished according to this invention by replacing the bearing cathode element tungsten by rhenium which also possesses a very high melting point. The dipole momentum between the elements thorium and rhenium is considerably higher than between thorium and tungsten, so that the electron emission performance is proportionately reduced. This 30 effect is causitive to the classification of thorium and rhenium in the periodic system.
Although the rhenium does not form any carbide, it involves such high absorption properties with respect to thorium that no appreciable evaporation of the thorium from its superficies will take place at normal operating temperatures of say 1800 degrees centigrade.
The manufacture of thoriated rhenium cath- 5 odes is similar to that of thoriated tungsten cathodes. To the metallic rhenium powder there is added up to 10 per cent of powdered rhenium oxide. This mixture is first compressed at a high pressure and then sintered in a protective gase- 10 ous atmosphere, whereupon the resulting blocks are hammered to the desirable shape and size.
What is claimed is:
1. The method of producing cathode materials which comprises mixing metallic rhenium pow- 15 der and an additional amount up to 10 per cent of pulverized thorium oxide, compressing the resulting mixture at high pressure, and sintering the compressed compound in a protective gaseous atmosphere. 20
2. The method of producing cathodes for electron discharge devices which comprises mixing metallic rhenium powder and an additional amount of up to 10-per cent of pulverized thorium oxide, compressing this mixture at high pressure, sintering the compressed compound in a protective gaseous atmosphere, and hammering the resulting blocks to the desirable shape and size.
3. As a product of manufacture, a cathode for electron discharge devices consisting of rhenium and an additional amount of up to 10 per cent of thorium.
FELIX HERRIGER.
US311136A 1938-12-02 1939-12-27 Method of producing cathode materials Expired - Lifetime US2214902A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE215769X 1938-12-02

Publications (1)

Publication Number Publication Date
US2214902A true US2214902A (en) 1940-09-17

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ID=5825698

Family Applications (1)

Application Number Title Priority Date Filing Date
US311136A Expired - Lifetime US2214902A (en) 1938-12-02 1939-12-27 Method of producing cathode materials

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US (1) US2214902A (en)
CH (1) CH215769A (en)
FR (1) FR868423A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2520760A (en) * 1946-03-05 1950-08-29 Csf Method of producing cathodes for electronic tubes
US2733319A (en) * 1950-07-14 1956-01-31 Material for electric contacts
US2879432A (en) * 1956-03-16 1959-03-24 Gen Electric Electron emitter
US3175904A (en) * 1961-10-30 1965-03-30 New England Materials Lab Inc Dispersion strengthening of platinumbase alloys

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2520760A (en) * 1946-03-05 1950-08-29 Csf Method of producing cathodes for electronic tubes
US2733319A (en) * 1950-07-14 1956-01-31 Material for electric contacts
US2879432A (en) * 1956-03-16 1959-03-24 Gen Electric Electron emitter
US3175904A (en) * 1961-10-30 1965-03-30 New England Materials Lab Inc Dispersion strengthening of platinumbase alloys

Also Published As

Publication number Publication date
FR868423A (en) 1941-12-30
CH215769A (en) 1941-07-15

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