US2450007A - Carburized filament and method for treating the same - Google Patents
Carburized filament and method for treating the same Download PDFInfo
- Publication number
- US2450007A US2450007A US466567A US46656742A US2450007A US 2450007 A US2450007 A US 2450007A US 466567 A US466567 A US 466567A US 46656742 A US46656742 A US 46656742A US 2450007 A US2450007 A US 2450007A
- Authority
- US
- United States
- Prior art keywords
- carburized
- filament
- same
- treating
- core
- 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
Links
- 238000000034 method Methods 0.000 title description 13
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 9
- 229910052721 tungsten Inorganic materials 0.000 description 7
- 239000010937 tungsten Substances 0.000 description 7
- 238000005452 bending Methods 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 2
- 240000005020 Acaciella glauca Species 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005255 carburizing Methods 0.000 description 1
- 238000003776 cleavage reaction Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 230000004807 localization Effects 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 235000003499 redwood Nutrition 0.000 description 1
- 230000007017 scission Effects 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
Images
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
- H01J1/14—Solid thermionic cathodes characterised by the material
-
- 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
- Y10T428/12431—Foil or filament smaller than 6 mils
- Y10T428/12438—Composite
-
- 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
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24355—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
- Y10T428/24471—Crackled, crazed or slit
-
- 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
- Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
- Y10T428/2913—Rod, strand, filament or fiber
- Y10T428/2918—Rod, strand, filament or fiber including free carbon or carbide or therewith [not as steel]
- Y10T428/292—In coating or impregnation
Definitions
- This invention relates to improvements in carburized filaments and methods for treating the same, and more particularly to an improved method for reducing the brittleness of carburized tungsten laments.
- An object of this inventionY is to provide a pliable carburized tungsten filament.
- Another object of this invention is to provide a method for reducing the brittleness of any carburlzed wire.
- Still another, more comprehensive object of this invention is directed to a method for restraightening carburized tungsten laments.
- Fig. l is a cross-section of' an untreated carburized tungsten wire
- Fig. 2 is ya similar cross-section of a tungsten Wire treated in accordance with the method of this invention.
- the carburization of tungsten or thoriated tungsten filaments is a step which has become common practice in the filament art. After the laments have been formed they are heated in a carburizing atmosphere resulting in a thin layer of carburized tungsten surrounding an inner core of relatively pure metal. In most instances, however, the carburization process tends to distort the filaments so that a re-straightening of the same is necessary. Before such restraightening process the filaments have a tendency to break since they have become brittle. The reason for this brittleness and breakage, apparently, is that small cracks and fissures are formed in the outer carburized layer which extend through this layer and terminate on the virgin meta] beneath.
- Fig. l illustrates, in a greatly enlarged cross-section, such a filament having an inner core I and a carburized layer l2.
- the cracks I4 appearing in the carburized layer I 2 are shown as extending into the core Ill, particularly where the Wire is sharply bent resulting, in certain instances, in a through crack such as indicated at I6.
- the effective brittleness of the filament is reduced and breakage is prevented by flashing or otherwise heating the carburized iilament in a 23, 1942, Serial No. 466,567 1 claim. (C1. 25o-27.5)
- the medium inert to the carburized filament for example, a gas such as hydrogen or helium, and bending the iilament into shape while the same is still hot and is still in the inert medium.
- This heating of the filament makes the inner core too ductile to break and the moving of the wire resulting from the re-straightening of the iilament while h'ot results in shearing stresses which tend to separate the core from its outer carburized sheath.
- the net result of this lamellar fracture is that stresses resulting from the radial fractures in the carburized layer are no longer localized and core fracture liability is accordingly reduced.
- the hydrogen flash after carburization appears to alter the crystal structure of the carbide layer and, after bending, viewed under the microscope the layer shows a very marked iine grain fracture pattern, the whole surface being crazed
- the carbide llayer acts as a true coating
- in the casev of untreated wire it is merely a fractured surface applying stresses to the inner core at relatively few cleavage points.
- the minute "craaing accordingly prevents localization of stresses at a few selected points, and hence under distortion, such as bending, the core in addition to now being more ductile is not subjected to as high localized stresses.
- a filament which has been treated in accordance with the present invention is illustrated by way of example in Fig. 2. It shows an inner core 20 of substantially virgin metal surrounded by an outer tungsten carbide layer 22 filled with a relatively large number of minute cracks 24.
- the lamellar separation between. the outer layer 22 and the core 20 is indicated on. an exaggerated scale at 26. This separation between the outer layer and core also prevents the cracks 24 from extending into the inner core 201, in contrast to the direct penetration of the cracks, as illustrated in Fig. 1.
Landscapes
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BE461800D BE461800A (ko) | 1942-11-23 | ||
US466567A US2450007A (en) | 1942-11-23 | 1942-11-23 | Carburized filament and method for treating the same |
GB19380/43A GB574430A (en) | 1942-11-23 | 1943-11-19 | Carburised filaments and methods for treating the same |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US466567A US2450007A (en) | 1942-11-23 | 1942-11-23 | Carburized filament and method for treating the same |
Publications (1)
Publication Number | Publication Date |
---|---|
US2450007A true US2450007A (en) | 1948-09-28 |
Family
ID=23852256
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US466567A Expired - Lifetime US2450007A (en) | 1942-11-23 | 1942-11-23 | Carburized filament and method for treating the same |
Country Status (3)
Country | Link |
---|---|
US (1) | US2450007A (ko) |
BE (1) | BE461800A (ko) |
GB (1) | GB574430A (ko) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2647067A (en) * | 1949-09-10 | 1953-07-28 | Eitel Mccullough Inc | Electron emitter for electron tubes |
US2674542A (en) * | 1951-02-06 | 1954-04-06 | Metal Hydrides Inc | Method for producing hard surfaced titanium |
US2819991A (en) * | 1952-08-30 | 1958-01-14 | Rca Corp | Carburized thoriated tungsten electrode and method of enhancing its emissivity |
US2873518A (en) * | 1954-02-26 | 1959-02-17 | Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh | Wire electrode for electric discharge lamps |
US3389977A (en) * | 1964-08-05 | 1968-06-25 | Texas Instruments Inc | Tungsten carbide coated article of manufacture |
US3494749A (en) * | 1967-08-02 | 1970-02-10 | Roman F Arnoldy | Abrasion resistant plate |
US4196368A (en) * | 1977-09-07 | 1980-04-01 | Eikonix Corporation | Improving incandescent bulb efficiency |
EP1987529A2 (en) * | 2006-02-08 | 2008-11-05 | Varian Medical Systems Technologies, Inc. | Improved cathode structures for x-ray tubes |
Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE214490C (ko) * | ||||
US716311A (en) * | 1902-05-23 | 1902-12-16 | Gen Electric | Electrical conductor. |
US1230869A (en) * | 1907-06-14 | 1917-06-26 | Gen Electric | Method of making incandescent lamps. |
US1593181A (en) * | 1915-12-29 | 1926-07-20 | Westinghouse Lamp Co | Method of working refractory metals |
US1663547A (en) * | 1923-07-17 | 1928-03-27 | Westinghouse Lamp Co | Refractory material and the activation thereof |
CH132146A (de) * | 1927-03-09 | 1929-03-31 | Erber Bernhard | Elektrische Glühlampe mit einem Leuchtkörper, der mindestens zum Teil aus einem Karbid eines Metalles der Tantalgruppe besteht. |
US1851573A (en) * | 1932-03-29 | elsey | ||
US1862138A (en) * | 1928-05-03 | 1932-06-07 | Westinghouse Electric & Mfg Co | Carbonized electrode and method of producing same |
US1893286A (en) * | 1928-05-25 | 1933-01-03 | Westinghouse Lamp Co | Method of carbonizing metals and alloys |
US1908759A (en) * | 1929-01-25 | 1933-05-16 | Westinghouse Lamp Co | Process of carbonizing metals |
US2051828A (en) * | 1933-10-31 | 1936-08-25 | Gilby Wire Company | Method of making carbonized nickel and nickel alloys |
US2069407A (en) * | 1930-07-29 | 1937-02-02 | Gen Electric | Thermionic cathode and process of activation |
US2095105A (en) * | 1935-10-01 | 1937-10-05 | Gen Electric | Process of treating metal surfaces |
US2282097A (en) * | 1940-03-29 | 1942-05-05 | Warren G Taylor | Nonemitting electrode structure |
US2305555A (en) * | 1940-09-26 | 1942-12-15 | Meiville F Peters | Electrical conductor |
-
0
- BE BE461800D patent/BE461800A/xx unknown
-
1942
- 1942-11-23 US US466567A patent/US2450007A/en not_active Expired - Lifetime
-
1943
- 1943-11-19 GB GB19380/43A patent/GB574430A/en not_active Expired
Patent Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1851573A (en) * | 1932-03-29 | elsey | ||
DE214490C (ko) * | ||||
US716311A (en) * | 1902-05-23 | 1902-12-16 | Gen Electric | Electrical conductor. |
US1230869A (en) * | 1907-06-14 | 1917-06-26 | Gen Electric | Method of making incandescent lamps. |
US1593181A (en) * | 1915-12-29 | 1926-07-20 | Westinghouse Lamp Co | Method of working refractory metals |
US1663547A (en) * | 1923-07-17 | 1928-03-27 | Westinghouse Lamp Co | Refractory material and the activation thereof |
CH132146A (de) * | 1927-03-09 | 1929-03-31 | Erber Bernhard | Elektrische Glühlampe mit einem Leuchtkörper, der mindestens zum Teil aus einem Karbid eines Metalles der Tantalgruppe besteht. |
US1862138A (en) * | 1928-05-03 | 1932-06-07 | Westinghouse Electric & Mfg Co | Carbonized electrode and method of producing same |
US1893286A (en) * | 1928-05-25 | 1933-01-03 | Westinghouse Lamp Co | Method of carbonizing metals and alloys |
US1908759A (en) * | 1929-01-25 | 1933-05-16 | Westinghouse Lamp Co | Process of carbonizing metals |
US2069407A (en) * | 1930-07-29 | 1937-02-02 | Gen Electric | Thermionic cathode and process of activation |
US2051828A (en) * | 1933-10-31 | 1936-08-25 | Gilby Wire Company | Method of making carbonized nickel and nickel alloys |
US2095105A (en) * | 1935-10-01 | 1937-10-05 | Gen Electric | Process of treating metal surfaces |
US2282097A (en) * | 1940-03-29 | 1942-05-05 | Warren G Taylor | Nonemitting electrode structure |
US2305555A (en) * | 1940-09-26 | 1942-12-15 | Meiville F Peters | Electrical conductor |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2647067A (en) * | 1949-09-10 | 1953-07-28 | Eitel Mccullough Inc | Electron emitter for electron tubes |
US2674542A (en) * | 1951-02-06 | 1954-04-06 | Metal Hydrides Inc | Method for producing hard surfaced titanium |
US2819991A (en) * | 1952-08-30 | 1958-01-14 | Rca Corp | Carburized thoriated tungsten electrode and method of enhancing its emissivity |
US2873518A (en) * | 1954-02-26 | 1959-02-17 | Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh | Wire electrode for electric discharge lamps |
US3389977A (en) * | 1964-08-05 | 1968-06-25 | Texas Instruments Inc | Tungsten carbide coated article of manufacture |
US3494749A (en) * | 1967-08-02 | 1970-02-10 | Roman F Arnoldy | Abrasion resistant plate |
US4196368A (en) * | 1977-09-07 | 1980-04-01 | Eikonix Corporation | Improving incandescent bulb efficiency |
EP1987529A2 (en) * | 2006-02-08 | 2008-11-05 | Varian Medical Systems Technologies, Inc. | Improved cathode structures for x-ray tubes |
EP1987529B1 (en) * | 2006-02-08 | 2017-07-19 | Varex Imaging Corporation | Improved cathode structure for x-ray tubes |
Also Published As
Publication number | Publication date |
---|---|
GB574430A (en) | 1946-01-04 |
BE461800A (ko) |
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