US3200284A - Platinum coated molybdenum grid having an intermediate layer of nickel - Google Patents
Platinum coated molybdenum grid having an intermediate layer of nickel Download PDFInfo
- 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
Links
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 title claims description 32
- 229910052697 platinum Inorganic materials 0.000 title claims description 16
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 title claims description 9
- 229910052750 molybdenum Inorganic materials 0.000 title claims description 6
- 239000011733 molybdenum Substances 0.000 title claims description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 title description 16
- 229910052759 nickel Inorganic materials 0.000 title description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims 2
- 229910017052 cobalt Inorganic materials 0.000 claims 1
- 239000010941 cobalt Substances 0.000 claims 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims 1
- 229910052742 iron Inorganic materials 0.000 claims 1
- 238000010438 heat treatment Methods 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 2
- 238000004070 electrodeposition Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 241001279686 Allium moly Species 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910000480 nickel oxide Inorganic materials 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 238000005488 sandblasting Methods 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
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"
Description
Aug. 10, 1965 M. A. M. BAKK PLATINUM COATED MOLY INTERMEDIATE Filed Ma ER ET BDENUM GRID HAVING AN LAYER OF NICKEL MARTINUS A-M. BAKKER. JOHANNES CH. DURAN.
BY I M ie e K United States Patent 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.
It is known that a lar importance in transmitting tubes in which the grids often assume a very high temperature.
When a grid consisting of molybdenum wire in its definite shape is coated by electro-deposition with a platinum layer without using further means, it is found that this layer at a suflicient strength disengages during operation of the discharge tube and finally surrounds the molybdenum wire like a rolled down stocking.
It is known to manufacture grids from an Mo-Wire which is previously surrounded by a Pt-cylinder and, after heating in a furnace to 135 0 C. is rolled or stretched in a reducing atmosphere to form a thin wire. If desired, the molybdenum core wire with a nickel layer so that it is adapted to slide with accurate fit in a Pt-cylinder. The intermediate nickel layer then serves as solder for the platinum outer layer.
It is found that grids manufactured from such platinum-coated wire are subjected to deformation and warping during operation, in which event even breakage of the wires may occur.
It is known that it is not possible to coat a molybdenum grid which has already obtained its Such a rough intermediate layer may be obtained by applying the metal in the form of oxide which is reduced by heating in a reducing atmosphere.
Now it is found that, as a result of the rough structure of the mtermediate layer, the above-mentioned difiiculties layer which is Consequently heating and during operation, the attachment is further improved by relative diffusion of the metals. Now it is found that the platinum layer does not burst during manufacture, while by appropriate choice of the thicknesses of fixed. During subsequent the intermediate layer and of the platinum layer 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.
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.
Furthermore, it is found that the intermediate layer the platinum layer as a result of the difference between of platinum and molybdenum.
The invention will now be described more fully with reference to the drawing, in which:
FIG. 1 shows a grid according to the invention, and
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"
What is claimed is: 1. A grid for an a thickness of about 5 to 10 and an intermediate layer of nickel firmly bonding said outer platinum layer to said base, said nickel layer having a thickness of about 0.1,u.
References Cited by the Examiner UNITED STATES PATENTS GEORGE N. WESTBY, Primary Examiner. RALPH G. NILSON, Examiner.
Claims (1)
1. A GRID FOR AN ELECTRIC DISCHARGE TUBE COMPRISING A BASE OF MOLYBDENUM, AN OUTER LAYER OF PLATINUM, AND AN INTERMEDIATE LAYER OF A METAL SELECTED FROM THE GROUP CONSISTING OF IRON, COBALT, AND NICKEL FIRMLY BONDING SAID PLATINUM LAYER TO SAID BASE, SAID INTERMEDIATE LAYER HAVING A THICKNESS LESS THAN HALF THAT OF THE PLATINUM LAYER.
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 (en) |
| CH (1) | CH393551A (en) |
| DE (1) | DE1233229B (en) |
| GB (1) | GB906961A (en) |
Cited By (2)
| 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)
| 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 |
-
1961
- 1961-05-26 US US112816A patent/US3200284A/en not_active Expired - Lifetime
- 1961-07-21 GB GB26522/61A patent/GB906961A/en not_active Expired
- 1961-07-24 DE DEN20367A patent/DE1233229B/en active Pending
- 1961-07-24 CH CH871261A patent/CH393551A/en unknown
Patent Citations (4)
| 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)
| 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 |
|---|---|
| GB906961A (en) | 1962-09-26 |
| DE1233229B (en) | 1967-01-26 |
| CH393551A (en) | 1965-06-15 |
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