US3323882A - Composite grid wire for electron tubes - Google Patents

Composite grid wire for electron tubes Download PDF

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Publication number
US3323882A
US3323882A US599364A US59936466A US3323882A US 3323882 A US3323882 A US 3323882A US 599364 A US599364 A US 599364A US 59936466 A US59936466 A US 59936466A US 3323882 A US3323882 A US 3323882A
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US
United States
Prior art keywords
core
wire
composite
electron tubes
grid wire
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
US599364A
Inventor
Henry J Albert
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.)
BASF Catalysts LLC
Engelhard Industries Inc
Original Assignee
Engelhard Industries Inc
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 Engelhard Industries Inc filed Critical Engelhard Industries Inc
Priority to US599364A priority Critical patent/US3323882A/en
Priority to GB05478/67A priority patent/GB1178151A/en
Priority to DE19671558488 priority patent/DE1558488B2/en
Application granted granted Critical
Publication of US3323882A publication Critical patent/US3323882A/en
Assigned to ENGELHARD CORPORATION reassignment ENGELHARD CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: PHIBRO CORPORATION, A CORP. OF DE
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • H01J1/46—Control electrodes, e.g. grid; Auxiliary electrodes
    • H01J1/48—Control electrodes, e.g. grid; Auxiliary electrodes characterised by the material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/02—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of metals or alloys
    • 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
    • H01J2893/002—Chemical composition and manufacture chemical
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12424—Mass of only fibers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12465—All metal or with adjacent metals having magnetic properties, or preformed fiber orientation coordinate with shape
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y10T428/12812—Diverse refractory group metal-base components: alternative to or next to each other
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y10T428/12826—Group VIB metal-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12861—Group VIII or IB metal-base component

Definitions

  • Such coated grids while effectively inhibiting electron emission, have a tendency to become embrittled when employed for long periods at the elevated operating temperatures of the tubes, the embrittlement being caused by the grain-growth of the grid metal with a consequent short stress-rupture time which limits the useful life of the grid.
  • a grid wire having a core composed of about 50/50 molybdenum-rhenium alloy with the core being coated with a layer of titanium provides an effective emission inhibiting grid structure which is characterized by high tensile strength and resistance against breakage by creep and grain-growth at elevated temperatures when the core metal is in a fibrous form of interfused wires.
  • a substantially heavy-walled titanium tube is prepared.
  • the tube may have a wall thickness of about 0.065" with an OD. of about 0.540" and a length of about 6.0".
  • a suitable length of wire having a diameter of about 0.20 and composed of about 50/50 molybdenumrhenium alloy is provided.
  • the term about 50/50 molybdenum-rhenium alloy includes an alloy composition of 48%-52% molybdenum and 52%-48% rhenium by weight percent.
  • the wire is cut into lengths of about ice 6.0" to substantially correspond with the length of the titanium tube. Both the titanium tube and the molybdenum-rhenium wires are thoroughly cleaned by known procedure to remove surface contaminants. Between about to about 200 of the wires are inserted into the titanium tube and the composite rod is reduced by cold swaging initially to about 50% reduction which is possible due to the elimination of the voids between the wires.
  • the composite rod is reduced to wire by alternately annealing and cold drawing with the average reduction between anneals ranging from about 25% to about 37.5% reduction.
  • the annealing is accomplished by heating the composite in vacuum at about 1000 C., for example, between about 1200 C. to 1600 C. for from 2 to 3 hours, and the wire is thusly drawn to about 0.032 diameter.
  • the core wires became interfused into a mass having a fibrous grain structure such that the fibrous grains are elongated along the length of the core and the core is bonded directly to the coating layer.
  • the composite wire of the invention When the composite wire of the invention is employed as a grid in electron tubes operating at high temperatures, there is practically no embrittlement of the grid because the transformation of the plurality of core wires by interfusion into a fibrous mass of elongated grains resists embrittlement at high operating temperatures by inhibiting grain-growth of the core grains.
  • the composite grid wire of the invention is characterized by a long useful life during operation of the electron tubes.
  • a composite emission inhibiting gn'd wire for electron tubes comprising a core in the form of a mass of interfused wires in fibrous form composed of an alloy of 48% to 52% molybdenum and 52% to 48% rhenium, and a coating of titanium bonded directly to the core.

Landscapes

  • Solid Thermionic Cathode (AREA)

Description

United States Patent 3 323 882 COlWPOSlTE GRID WIRE FOR ELECTRON TUBES Henry J. Albert, Colts Neck, NJ., assignor to Engelhard Industries, Inc., Newark, N.J., a corporation of Delaware No Drawing. Filed Dec. 6, 1966, Ser. No. 599,364 3 Claims. (Cl. 29-193) ABSTRACT OF THE DISCLOSURE The present invention deals with a composite emission inhibiting grid wire for electron tubes which resists embrittlement at high operating temperatures, which has high tensile strength and maintains a resistance against grain-growth and creep at elevated temperatures, and which is composed of a core of interfused wires of a 50/50 molybdenum-rhenium alloy with the core being coated with titanium.
Background of the invention In electron tubes employing hot electron emissive cathodes of the activated type, e.g. thoriated cathodes, in conjunction with grids of a refractory material, e.g. tungsten, tantalum and molybdenum, which must be essentially free of activation material, it has been found that the grids suffer from contamination by the activation material and lose stability unless protected by an electron emission inhibiting material. Generally, the grids are coated with an electron emission inhibiting material comprising a coating of platinum, gold or titanium.
Such coated grids, while effectively inhibiting electron emission, have a tendency to become embrittled when employed for long periods at the elevated operating temperatures of the tubes, the embrittlement being caused by the grain-growth of the grid metal with a consequent short stress-rupture time which limits the useful life of the grid.
Summary of the invention In accordance with the invention, it has been found that a grid wire having a core composed of about 50/50 molybdenum-rhenium alloy with the core being coated with a layer of titanium provides an effective emission inhibiting grid structure which is characterized by high tensile strength and resistance against breakage by creep and grain-growth at elevated temperatures when the core metal is in a fibrous form of interfused wires.
Description of the preferred embodiments In providing the composite grid wire of the invention, a substantially heavy-walled titanium tube is prepared. For example, the tube may have a wall thickness of about 0.065" with an OD. of about 0.540" and a length of about 6.0".
Also, a suitable length of wire having a diameter of about 0.20 and composed of about 50/50 molybdenumrhenium alloy is provided. The term about 50/50 molybdenum-rhenium alloy includes an alloy composition of 48%-52% molybdenum and 52%-48% rhenium by weight percent. The wire is cut into lengths of about ice 6.0" to substantially correspond with the length of the titanium tube. Both the titanium tube and the molybdenum-rhenium wires are thoroughly cleaned by known procedure to remove surface contaminants. Between about to about 200 of the wires are inserted into the titanium tube and the composite rod is reduced by cold swaging initially to about 50% reduction which is possible due to the elimination of the voids between the wires. Thereafter, the composite rod is reduced to wire by alternately annealing and cold drawing with the average reduction between anneals ranging from about 25% to about 37.5% reduction. The annealing is accomplished by heating the composite in vacuum at about 1000 C., for example, between about 1200 C. to 1600 C. for from 2 to 3 hours, and the wire is thusly drawn to about 0.032 diameter. During the Working of the composite wire, the core wires became interfused into a mass having a fibrous grain structure such that the fibrous grains are elongated along the length of the core and the core is bonded directly to the coating layer.
The mechanical properties of the resultant composite Wire is shown in the following table:
-It will be seen that the elongation of the composite wire is substantially constant in both the cold worked and annealed condition, which is a result of the core composed of the fibrous interfused wires.
When the composite wire of the invention is employed as a grid in electron tubes operating at high temperatures, there is practically no embrittlement of the grid because the transformation of the plurality of core wires by interfusion into a fibrous mass of elongated grains resists embrittlement at high operating temperatures by inhibiting grain-growth of the core grains.
Consequently, the composite grid wire of the invention is characterized by a long useful life during operation of the electron tubes.
What is claimed is:
1. A composite emission inhibiting gn'd wire for electron tubes, comprising a core in the form of a mass of interfused wires in fibrous form composed of an alloy of 48% to 52% molybdenum and 52% to 48% rhenium, and a coating of titanium bonded directly to the core.
2. A composite grid wire according to claim 1, wherein the core is composed of a 50/50 molybdenum rhenium alloy.
3. A composite grid wire according to claim 1, wherein the composite wire is characterized by a substantially constant elongation both in the cold-worked and annealed conditions.
No references cited.
HYLAND BIZOT, Primary Examiner.

Claims (1)

1. A COMPOSITE EMISSION INHIBITING GRID WIRE FOR ELECTRON TUBES, COMPRISING A CORE IN THE FORM OF A MASS OF INTERFUSED WIRES IN FIBROUS FORM COMPOSED OF AN ALLOY OF 48% TO 52% MOLYBDENUM AND 52% TO 48% RHENIUM, AND A COATING OF TITANIUM BONDED DIRECTLY TO THE CORE.
US599364A 1966-12-06 1966-12-06 Composite grid wire for electron tubes Expired - Lifetime US3323882A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US599364A US3323882A (en) 1966-12-06 1966-12-06 Composite grid wire for electron tubes
GB05478/67A GB1178151A (en) 1966-12-06 1967-04-04 Grid Wire for Electron Tubes
DE19671558488 DE1558488B2 (en) 1966-12-06 1967-05-17 ELECTRON EMISSION-INHIBITING COMPOSITE WIRE FOR THE MANUFACTURING OF GRIDS FOR ELECTRON TUBES

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US599364A US3323882A (en) 1966-12-06 1966-12-06 Composite grid wire for electron tubes

Publications (1)

Publication Number Publication Date
US3323882A true US3323882A (en) 1967-06-06

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ID=24399318

Family Applications (1)

Application Number Title Priority Date Filing Date
US599364A Expired - Lifetime US3323882A (en) 1966-12-06 1966-12-06 Composite grid wire for electron tubes

Country Status (3)

Country Link
US (1) US3323882A (en)
DE (1) DE1558488B2 (en)
GB (1) GB1178151A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190362864A1 (en) * 2018-05-25 2019-11-28 General Cable Technologies Corporation Ultra-conductive wires and methods of forming thereof
US10861616B2 (en) 2018-07-23 2020-12-08 General Cable Technologies Corporation Cables exhibiting increased ampacity due to lower temperature coefficient of resistance

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190362864A1 (en) * 2018-05-25 2019-11-28 General Cable Technologies Corporation Ultra-conductive wires and methods of forming thereof
US10685760B2 (en) * 2018-05-25 2020-06-16 General Cable Technologies Corporation Ultra-conductive wires and methods of forming thereof
US10861616B2 (en) 2018-07-23 2020-12-08 General Cable Technologies Corporation Cables exhibiting increased ampacity due to lower temperature coefficient of resistance

Also Published As

Publication number Publication date
DE1558488B2 (en) 1972-01-20
DE1558488A1 (en) 1970-04-09
GB1178151A (en) 1970-01-21

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Date Code Title Description
AS Assignment

Owner name: ENGELHARD CORPORATION 70 WOOD AVENUE SOUTH, METRO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:PHIBRO CORPORATION, A CORP. OF DE;REEL/FRAME:003968/0801

Effective date: 19810518