DE1091673B - Process for the manufacture of a cathode for electrical discharge tubes - Google Patents
Process for the manufacture of a cathode for electrical discharge tubesInfo
- Publication number
- DE1091673B DE1091673B DEN9037A DEN0009037A DE1091673B DE 1091673 B DE1091673 B DE 1091673B DE N9037 A DEN9037 A DE N9037A DE N0009037 A DEN0009037 A DE N0009037A DE 1091673 B DE1091673 B DE 1091673B
- Authority
- DE
- Germany
- Prior art keywords
- cathode
- electrical discharge
- discharge tubes
- manufacture
- pressed
- 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.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 238000000034 method Methods 0.000 title claims description 6
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Chemical compound [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 claims description 14
- 239000000203 mixture Substances 0.000 claims description 8
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 239000000155 melt Substances 0.000 claims description 3
- 238000002844 melting Methods 0.000 claims description 2
- 238000003825 pressing Methods 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 description 5
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 4
- 229910052750 molybdenum Inorganic materials 0.000 description 4
- 239000011733 molybdenum Substances 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 3
- 239000003870 refractory metal Substances 0.000 description 2
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- QKYBEKAEVQPNIN-UHFFFAOYSA-N barium(2+);oxido(oxo)alumane Chemical compound [Ba+2].[O-][Al]=O.[O-][Al]=O QKYBEKAEVQPNIN-UHFFFAOYSA-N 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
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
- Discharge Lamp (AREA)
- Solid Thermionic Cathode (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Description
Die Erfindung bezieht sich auf ein Verfahren zur Herstellung einer Kathode für elektrische Entladungsröhren, die aus einem gepreßten und gesinterten Gemisch von pulverförmigem, hochschmelzendem Metall und einer geschmolzenen Mischung aus Bariumoxyd und Aluminiumoxyd besteht, nach Anspruch 10 des Hauptpatentes.The invention relates to a method for producing a cathode for electrical discharge tubes, made from a pressed and sintered mixture of powdery, refractory metal and a molten mixture of barium oxide and aluminum oxide exists, according to claim 10 of the main patent.
Im Hauptpatent ist eine Herstellungsweise angegeben, wonach pulvriges Wolfram und pulvriges Bariumaluminat gemischt, gepreßt und auf eine Temperatur von angenähert 137O0C erhitzt werden, so daß sich ein einheitlicher Körper ergibt. Es hat sich herausgestellt, daß die auf diese Weise hergestellten Kathoden nicht immer leicht zur Emission aktivierbar sind, während auch die mechanische Stärke nicht immer befriedigend ist. Die Erfindung bezweckt, die Kathoden der vorstehend erwähnten Art und das Verfahren zu ihrer Herstellung zu verbessern.The main patent specifies a production method, according to which powdery tungsten and powdery barium aluminate are mixed, pressed and heated to a temperature of approximately 137O 0 C, so that a uniform body results. It has been found that the cathodes produced in this way are not always easy to activate for emission, while the mechanical strength is not always satisfactory either. The invention aims to improve the cathodes of the type mentioned above and the process for their manufacture.
Bei einem Verfahren zur Herstellung einer Kathode für elektrische Entladungsröhren, die aus einem gepreßten und gesinterten Gemisch von pulverförmigem, hochschmelzendem Metall und einer geschmolzenen Mischung aus Bariumoxyd und Aluminiumoxyd besteht, nach Anspruch 10 des Hauptpatentes, wird gemäß der Erfindung das pulverförmige Metall mit im Molekularverhältnis 5: 2 vermischtem Bariumoxyd und Aluminiumoxyd gemischt, gepreßt, nach dem Pressen während 30 Sekunden auf eine Temperatur von 1650 bis 17500C, bei der die Mischung zwischen dem Bariumoxyd und Aluminiumoxyd schmilzt, erhitzt und dann rasch abgekühlt.In a method for the production of a cathode for electrical discharge tubes, which consists of a pressed and sintered mixture of powdery, high-melting metal and a molten mixture of barium oxide and aluminum oxide, according to claim 10 of the main patent, the powdery metal is according to the invention with a molecular ratio of 5 : 2 mixed barium oxide and aluminum oxide mixed, pressed, after pressing for 30 seconds to a temperature of 1650 to 1750 0 C, at which the mixture between the barium oxide and aluminum oxide melts, heated and then rapidly cooled.
Infolge der hohen Erhitzung sintert die vorhandene Erdalkaliverbindung und vielleicht auch das hochschmelzende Metall fester zusammen. Hierdurch ergibt sich ein mechanisch sehr fester Kathodenkörper, der poliert, geschliffen und sogar mit einem Schneidewerkzeug bearbeitet werden kann. Die Kathoden sind auch weniger empfindlich gegen Luft, so daß eine Entladungsröhre mit einer solchen Kathode gegebenenfalls zum zweiten Male gepumpt werden kann. Auch ist der Kathodenkörper infolge der Erhitzung gut gasfrei geworden, und er läßt sich leichter zu einer guten Emission aktivieren. Da die Erdalkaliverbindung schmilzt, erfolgt die Erhitzung im Vakuum oder in einer inerten Atmosphäre. Es darf jedoch nicht so lange erhitzt werden, daß eine zu große Menge der Verbindung oder des frei werdenden Erdalkalimetalls verdampft.As a result of the high level of heating, the existing alkaline earth compound and perhaps also the refractory metal sinter together more firmly. This results in a mechanically very strong cathode body that is polished, ground and even with a cutting tool can be edited. The cathodes are also less sensitive to air, so use a discharge tube such a cathode can optionally be pumped a second time. Also is the cathode body has become well gas-free as a result of the heating, and it can be activated more easily to produce a good emission. Since the Alkaline earth compound melts, heating takes place in a vacuum or in an inert atmosphere. However, it is allowed not be heated so long that too large an amount of the compound or the liberated alkaline earth metal evaporates.
Das Verfahren nach der Erfindung wird im folgenden Anwendungsbeispiel an Hand der beiliegenden Zeichnung näher erläutert.The method according to the invention is illustrated in the following application example with reference to the accompanying drawing explained in more detail.
In der Zeichnung bezeichnet 1 ein Molybdänrohr, in dessen Innerem eine Heizwendel 2 angeordnet ist. Der eigentliche Kathodenkörper 3 ist im ausgedrehten oberen Ende des Molybdänrohrs 1 durch Schweißen oder Falzen befestigt.In the drawing, 1 denotes a molybdenum tube, in the interior of which a heating coil 2 is arranged. Of the The actual cathode body 3 is in the turned upper end of the molybdenum tube 1 by welding or folding attached.
Verfahren zur HerstellungMethod of manufacture
einer Kathode für elektrischea cathode for electrical
EntladungsröhrenDischarge tubes
Zusatz zum Patent 973 193Addendum to patent 973 193
Anmelder:Applicant:
N. V. Philips' Gloeilampenfabrieken,
Eindhoven (Niederlande)NV Philips' Gloeilampenfabrieken,
Eindhoven (Netherlands)
Vertreter: Dr. rer. nat. P. Roßbach, Patentanwalt,
Hamburg I1 Mönckebergstr. 7Representative: Dr. rer. nat. P. Roßbach, patent attorney,
Hamburg I 1 Mönckebergstr. 7th
Beanspruchte Priorität:
V. St. v. Amerika vom 11. Juni 1953Claimed priority:
V. St. v. America June 11, 1953
Patrick Paul Coppola, Dobbs Ferry, N. Y.,Patrick Paul Coppola, Dobbs Ferry, N.Y.,
Ray Collier Hughes, Ardsley, N. Y.,
und Otto Gustav Koppius, Whiteplains, N. Y.Ray Collier Hughes, Ardsley, NY,
and Otto Gustav Koppius, Whiteplains, NY
(V. St. A.),
sind als Erfinder genannt worden(V. St. A.),
have been named as inventors
Der Kathodenkörper 3 ist dadurch hergestellt, daß pulvriges Wolfram und im Molekularverhältnis von 5 : 2 vermischtes Bariumoxyd und Aluminiumoxyd in Mengen von 90 bzw. 10 °/0 des Gewichts gemischt werden. Dieses Gemisch wird unter einem Druck von 5 bis 10 t/cm2 zu einer runden, 1,5 mm dicken Platte gepreßt. Die gepreßte Platte wird in einem Molybdänbehälter in einem Vakuumofen während 30 Sekunden auf eine Temperatur von 1650 bis 1750° C gebracht und dann rasch abgekühlt. Darauf wird die Platte im Molybdänrohr angebracht und in einer Entladungsröhre angeordnet und darauf durch Erhitzen aktiviert. Der Sättigungsstrom betrug angenähert 2 A/cm2 bei einer Temperatur von 10000C. Bei einer Temperatur von 11300C beträgt die Lebensdauer wenigstens 2500 bis 3000 Stunden, wie aus der nachstehenden Tabelle für vier Röhren ersichtlich ist.The cathode body 3 is fabricated by powdered tungsten and the molecular ratio of 5: 2 mixed barium oxide and alumina in amounts of 90 and 10 respectively of the weight are mixed ° / 0th This mixture is pressed under a pressure of 5 to 10 t / cm 2 to form a round, 1.5 mm thick plate. The pressed plate is brought to a temperature of 1650 to 1750 ° C. in a molybdenum container in a vacuum furnace for 30 seconds and then rapidly cooled. The plate is then attached in the molybdenum tube and placed in a discharge tube and activated by heating. The saturation current was approximately 2 A / cm 2 at a temperature of 1000 ° C. At a temperature of 1130 ° C., the service life is at least 2500 to 3000 hours, as can be seen from the table below for four tubes.
Claims (1)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US322466XA | 1953-06-11 | 1953-06-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| DE1091673B true DE1091673B (en) | 1960-10-27 |
Family
ID=21863890
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DEN9037A Pending DE1091673B (en) | 1953-06-11 | 1954-06-10 | Process for the manufacture of a cathode for electrical discharge tubes |
Country Status (4)
| Country | Link |
|---|---|
| CH (1) | CH322466A (en) |
| DE (1) | DE1091673B (en) |
| FR (1) | FR1102034A (en) |
| GB (1) | GB753280A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1187730B (en) | 1961-01-02 | 1965-02-25 | Patra Patent Treuhand | Electrode for gas and / or vapor discharge lamps |
| DE1257980B (en) | 1966-05-20 | 1968-01-04 | Telefunken Patent | Supply cathode and process for their manufacture |
| DE2935447A1 (en) * | 1978-09-07 | 1980-03-20 | Tokyo Shibaura Electric Co | SINTER ELECTRODES SUITABLE FOR ELECTRIC GAS DISCHARGE LAMPS AND METHOD FOR THE PRODUCTION THEREOF |
-
1954
- 1954-06-09 GB GB16929/54A patent/GB753280A/en not_active Expired
- 1954-06-09 FR FR1102034D patent/FR1102034A/en not_active Expired
- 1954-06-09 CH CH322466D patent/CH322466A/en unknown
- 1954-06-10 DE DEN9037A patent/DE1091673B/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1187730B (en) | 1961-01-02 | 1965-02-25 | Patra Patent Treuhand | Electrode for gas and / or vapor discharge lamps |
| DE1257980B (en) | 1966-05-20 | 1968-01-04 | Telefunken Patent | Supply cathode and process for their manufacture |
| DE2935447A1 (en) * | 1978-09-07 | 1980-03-20 | Tokyo Shibaura Electric Co | SINTER ELECTRODES SUITABLE FOR ELECTRIC GAS DISCHARGE LAMPS AND METHOD FOR THE PRODUCTION THEREOF |
Also Published As
| Publication number | Publication date |
|---|---|
| FR1102034A (en) | 1955-10-13 |
| CH322466A (en) | 1957-06-15 |
| GB753280A (en) | 1956-07-18 |
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