US3200284A - Platinum coated molybdenum grid having an intermediate layer of nickel - Google Patents

Platinum coated molybdenum grid having an intermediate layer of nickel Download PDF

Info

Publication number
US3200284A
US3200284A US112816A US11281661A US3200284A US 3200284 A US3200284 A US 3200284A US 112816 A US112816 A US 112816A US 11281661 A US11281661 A US 11281661A US 3200284 A US3200284 A US 3200284A
Authority
US
United States
Prior art keywords
layer
nickel
platinum
intermediate layer
grid
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 - Lifetime
Application number
US112816A
Other languages
English (en)
Inventor
Bakker Martinus Antonius Maria
Duran Johannes Christiaan
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.)
US Philips Corp
North American Philips Co Inc
Original Assignee
US Philips Corp
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 US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3200284A publication Critical patent/US3200284A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/34—Pretreatment of metallic surfaces to be electroplated
    • C25D5/38—Pretreatment of metallic surfaces to be electroplated of refractory metals or nickel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
    • H01J19/28—Non-electron-emitting electrodes; Screens
    • H01J19/30—Non-electron-emitting electrodes; Screens characterised by the material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
    • H01J2893/0012—Constructional arrangements
    • H01J2893/0019—Chemical composition and manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
    • H01J2893/0012—Constructional arrangements
    • H01J2893/0019—Chemical composition and manufacture
    • H01J2893/002—Chemical composition and manufacture chemical
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
    • H01J2893/0012—Constructional arrangements
    • H01J2893/0019—Chemical composition and manufacture
    • H01J2893/0022—Manufacture
    • H01J2893/0023—Manufacture carbonising and other surface treatments

Definitions

  • the invention relates to a method of coating by electro-deposition a grid manufactured from molybdenum for electric discharge tubes so that during the whole life of the tube the platinum layer adheres satisfactorily and remains completely intact.
  • the attachment is further improved by relative diffusion of the metals.
  • the platinum layer does not burst during manufacture, while by appropriate choice of the thicknesses of fixed.
  • the time required for the difiusion of molybdenum from the core to the platinum surface is longer than the life (5000 hours) of the tube in which the grid is used, even at an operational temperature of about 1200 C. Owing to the initially obtained mechanical anchorage of the platinum layer, the latter adheres to the substratum during the whole life of the tube.
  • the diffusion of platinum in the core also proceeds so slowly that, when use is made of Consequently, of the grid are maintained.
  • the intermediate layer may be applied by immersing the molybdenum grid in a suspension of, for example nickel oxide, by drying and heating in a reducing atmosphere until the oxide is reduced to nickel.
  • the intermediate layer of, 10 microns and heated during a few hours at 1200 to 1500 C. If the weight of the intermediate layer does not ration of this layer occurs during operation of the discharge tube. A thickness of 0.1;]. has proved to be very favorable. If desired, the intermediate layer may also be provided by electro-deposition and roughened by sandblasting.
  • the intermediate layer the platinum layer as a result of the difference between of platinum and molybdenum.
  • FIG. 1 shows a grid according to the invention
  • FIG. 2 is a sectional view of a grid wire.
  • FIG. 1 shows a grid for transmitting tubes which coninterrnediate nickel layer 4 of 0.1 1"

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Solid Thermionic Cathode (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
  • Electroplating Methods And Accessories (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)
US112816A 1960-07-26 1961-05-26 Platinum coated molybdenum grid having an intermediate layer of nickel Expired - Lifetime US3200284A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL254219 1960-07-26

Publications (1)

Publication Number Publication Date
US3200284A true US3200284A (en) 1965-08-10

Family

ID=19752490

Family Applications (1)

Application Number Title Priority Date Filing Date
US112816A Expired - Lifetime US3200284A (en) 1960-07-26 1961-05-26 Platinum coated molybdenum grid having an intermediate layer of nickel

Country Status (4)

Country Link
US (1) US3200284A (de)
CH (1) CH393551A (de)
DE (1) DE1233229B (de)
GB (1) GB906961A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3337933A (en) * 1963-09-19 1967-08-29 Siemens Ag Screen grid tube with coaxial tubular mesh grids
US3772561A (en) * 1970-04-23 1973-11-13 Gte Sylvania Inc Electron discharge device grid having enhanced thermal conductivity and reduced secondary emission characteristics

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2539096A (en) * 1949-09-19 1951-01-23 Eitel Mccullough Inc Electron tube and grid for the same
US2821496A (en) * 1951-08-03 1958-01-28 Gen Electric Non-emissive grids
US2878549A (en) * 1955-11-18 1959-03-24 Telefunken Gmbh Manufacture of delicate grids
US3164740A (en) * 1960-04-29 1965-01-05 Rca Corp Electron tube grids and method of making the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2539096A (en) * 1949-09-19 1951-01-23 Eitel Mccullough Inc Electron tube and grid for the same
US2821496A (en) * 1951-08-03 1958-01-28 Gen Electric Non-emissive grids
US2878549A (en) * 1955-11-18 1959-03-24 Telefunken Gmbh Manufacture of delicate grids
US3164740A (en) * 1960-04-29 1965-01-05 Rca Corp Electron tube grids and method of making the same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3337933A (en) * 1963-09-19 1967-08-29 Siemens Ag Screen grid tube with coaxial tubular mesh grids
US3772561A (en) * 1970-04-23 1973-11-13 Gte Sylvania Inc Electron discharge device grid having enhanced thermal conductivity and reduced secondary emission characteristics

Also Published As

Publication number Publication date
DE1233229B (de) 1967-01-26
GB906961A (en) 1962-09-26
CH393551A (de) 1965-06-15

Similar Documents

Publication Publication Date Title
US2499977A (en) Method of forming grid-like structures
US2480453A (en) Method of manufacturing bodies consisting of a core of chrome-iron or a similar chromium alloy and of a thin layer adapted to form a metal to glass seal
US3200284A (en) Platinum coated molybdenum grid having an intermediate layer of nickel
US3271849A (en) Iridium-sheathed wire for electron tubes
GB1057909A (en) Method of manufacturing cathodes for electron tubes
US2610386A (en) Semiconductive cell
US3698050A (en) Method of producing a composite electrode
US2493951A (en) Process of hardening alloys by indiffusion of a metalloid
US3160946A (en) Electrical heaters
US2125896A (en) Article of manufacture and method of producing the same
US2848801A (en) Method of making ceramic metal seal
US1989236A (en) Composite wire
US2479446A (en) Method of manufacturing small current selenium rectifiers
US3113893A (en) Incandescent filament
US3816079A (en) Method of producing grid electrodes for electronic discharge vessels
GB976527A (en) Improvements relating to the manufacture of insulated wire
US3206329A (en) Insulation coating for indirectly heated cathode heaters
US3290170A (en) Oxidation-resistant coating method and coated article
US3342634A (en) Method of producing black, metalcontaining surface layers
US3311964A (en) Method of manufacturing a frame grid
US2819982A (en) Production of silver mirrors by volatilisation
US3404968A (en) Glass-to-metal seals and method for making same
US2746129A (en) Method of producing a taut thin member
US3632485A (en) Method of making an electron discharge device grid having enhanced thermal conductivity and reduced secondary emission characteristics
DE1021496B (de) Verfahren zur Herstellung einer Kathode fuer Gasentladungsroehren