US1800134A - Producing vacuums - Google Patents
Producing vacuums Download PDFInfo
- Publication number
- US1800134A US1800134A US417825A US41782529A US1800134A US 1800134 A US1800134 A US 1800134A US 417825 A US417825 A US 417825A US 41782529 A US41782529 A US 41782529A US 1800134 A US1800134 A US 1800134A
- Authority
- US
- United States
- Prior art keywords
- barium
- magnesium
- alloys
- vacuums
- air
- 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
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 10
- 239000011777 magnesium Substances 0.000 description 10
- 229910052788 barium Inorganic materials 0.000 description 9
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 9
- 229910045601 alloy Inorganic materials 0.000 description 8
- 239000000956 alloy Substances 0.000 description 8
- 229910052749 magnesium Inorganic materials 0.000 description 8
- 239000003795 chemical substances by application Substances 0.000 description 5
- 229910000600 Ba alloy Inorganic materials 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 150000002739 metals Chemical class 0.000 description 4
- 229910052712 strontium Inorganic materials 0.000 description 4
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 4
- 229910000861 Mg alloy Inorganic materials 0.000 description 3
- 239000008188 pellet Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000013543 active substance Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- IJBYNGRZBZDSDK-UHFFFAOYSA-N barium magnesium Chemical compound [Mg].[Ba] IJBYNGRZBZDSDK-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000000227 grinding Methods 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
- 239000012535 impurity Substances 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
- H01J7/14—Means for obtaining or maintaining the desired pressure within the vessel
- H01J7/18—Means for absorbing or adsorbing gas, e.g. by gettering
- H01J7/183—Composition or manufacture of getters
Definitions
- the invention relates to the production of high vacuums for any purpose, but particularly in hot cathode devices such as the tubes or valves used in radio communication.
- electron tubes are evacuated by pumping to a convenient degree of exhaustion, and then subjecting the residual gases to the action of a clean-up agent, which, it is believed, fixes the residual 1o gases by both chemical and physical action.
- Magnesium is the usual clean-up agent, but other substances, for example the metals barium and strontium, give higher vacuums under certain conditions. In attempting to substitute these latter metals for magnesium, dificulties are encountered because the metals require higher temperatures than magnesium to cause them to flash, that is to begin to react rapidly with the gases present.
- the usual method of flashing the clean-up agent is to introduce it in solid form into the envelope, then seal the envelope either temporarily or permanently, and then bring the envelope into the field of a coil in which highfrequency alternating current flows; and it is found that the equipment available, designed for flashing magnesium. mav not have enough power to flash barium and other very active agents within the time allotted to this operation in the semi-automatic machines used in making thermionic tubes. In the present large-scale manufacture of tubes, it is of course desirable to carry out each operation as rapidly as possible.
- An object of the invention is to facilitate the flashing of such agents as barium and strontium, and to adapt them to the equip ment and schedules now employed with magnesium. This is accomplished by alloyingthe barium or strontium with magnesium in such proportions as to produce stable alloys containing effective quantities of the former metals, powdering the resulting brittle alloys and compressing the powders which are selfbonding, into pellets of the desired size.
- alloys are quite brittle. This property does not constitute a serious objection as I have found that the powdered alloys have self bonding properties and can be readily agglomerated, as by pressing into pellets. Appropriate binders may be used if desired.
- pellets of the powdered alloy as stated are sta le in air and readily may be handled without objectionable contamination by vaporizable impurities.
- Barium-magnesium alloys can be easily repared by fusing the ingredients in an inert atmosphere, such as argon or helium, in
- a suitable vessel for example a crucible of commercially carbon-free iron.
- a suitable vessel for example a crucible of commercially carbon-free iron.
- pure barium I may substitute any barium alloy which is free from substances detrimental to a gas clean-up agent.
Description
i ITED- PATENT- OFFICE HUGE S. COOPER, OF CLEVELAND, OHIO, ASSIGNOR TO KEME'I' LABORATORIES COM- PANY, INC., A CORPORATION OF NEW YORK rnonucme vacuums No Drawing.
The invention relates to the production of high vacuums for any purpose, but particularly in hot cathode devices such as the tubes or valves used in radio communication.
In the prevailing practice, electron tubes are evacuated by pumping to a convenient degree of exhaustion, and then subjecting the residual gases to the action of a clean-up agent, which, it is believed, fixes the residual 1o gases by both chemical and physical action.
Magnesium is the usual clean-up agent, but other substances, for example the metals barium and strontium, give higher vacuums under certain conditions. In attempting to substitute these latter metals for magnesium, dificulties are encountered because the metals require higher temperatures than magnesium to cause them to flash, that is to begin to react rapidly with the gases present.
The usual method of flashing the clean-up agent is to introduce it in solid form into the envelope, then seal the envelope either temporarily or permanently, and then bring the envelope into the field of a coil in which highfrequency alternating current flows; and it is found that the equipment available, designed for flashing magnesium. mav not have enough power to flash barium and other very active agents within the time allotted to this operation in the semi-automatic machines used in making thermionic tubes. In the present large-scale manufacture of tubes, it is of course desirable to carry out each operation as rapidly as possible.
An object of the invention is to facilitate the flashing of such agents as barium and strontium, and to adapt them to the equip ment and schedules now employed with magnesium. This is accomplished by alloyingthe barium or strontium with magnesium in such proportions as to produce stable alloys containing effective quantities of the former metals, powdering the resulting brittle alloys and compressing the powders which are selfbonding, into pellets of the desired size.
The invention will be described more particularly hereinafter by reference to alloys of barium with magnesium.
Magnesium and barium alloy in all proportions, and certain of the alloys have been Application filed December 81, 1929. Serial No. 417,825.
found to be relatively stable in the air. It will be recognized that it is impossible to differentiate sharply between compositions which are stable in air and those which are not, especially since the action of the air varies with its humidity, but it may be stated that stability falls off with increasing barium content, and that alloys containing up to about 30% of barium are fairly stable in air. Alloys which are unstable in air are also useful, but they must be protected from prolonged exposure to air. As little as 10% of magnesium alloyed with barium will substantially lower the energy requirements for flashing the getter, while as little as 5% of barium increases the thoroughness of the clean-up. The alloys of barium and magnesium which are most suitable for my purose have little ductility as a rule and cannot e readily drawn into wire or other attenu ated forms. Some of the alloys are quite brittle. This property does not constitute a serious objection as I have found that the powdered alloys have self bonding properties and can be readily agglomerated, as by pressing into pellets. Appropriate binders may be used if desired.
The pellets of the powdered alloy as stated are sta le in air and readily may be handled without objectionable contamination by vaporizable impurities.
Barium-magnesium alloys can be easily repared by fusing the ingredients in an inert atmosphere, such as argon or helium, in
a suitable vessel, for example a crucible of commercially carbon-free iron. For pure barium I may substitute any barium alloy which is free from substances detrimental to a gas clean-up agent. Similarly, strontium
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US417825A US1800134A (en) | 1929-12-31 | 1929-12-31 | Producing vacuums |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US417825A US1800134A (en) | 1929-12-31 | 1929-12-31 | Producing vacuums |
Publications (1)
Publication Number | Publication Date |
---|---|
US1800134A true US1800134A (en) | 1931-04-07 |
Family
ID=23655533
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US417825A Expired - Lifetime US1800134A (en) | 1929-12-31 | 1929-12-31 | Producing vacuums |
Country Status (1)
Country | Link |
---|---|
US (1) | US1800134A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2464918A (en) * | 1945-03-22 | 1949-03-22 | Magnesium Elektron Ltd | Magnesium base alloys |
-
1929
- 1929-12-31 US US417825A patent/US1800134A/en not_active Expired - Lifetime
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2464918A (en) * | 1945-03-22 | 1949-03-22 | Magnesium Elektron Ltd | Magnesium base alloys |
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