US4859239A
Expired / Lapsed
US
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Tungsten electrode and method of producing same
Assignee: Osram Sylvania Inc
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Filing: 1988-12-20
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Granted: 1989-08-22
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Expires: 2008-12-20
Abstract
Abstract An electrode, and method of producing same, including tungsten which has been heated in wet hydrogen at 1050° C. for 5 to 10 minutes, then heated at about 1500° C. for about three hours in a vacuum, and then further heated at about 2800° C. for about 5 minutes in a vacuum.
Inventors
- 👤 Edmund M. Passmore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:30
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/16; C22F1/18; B; B22; B22F; B22F3/00; B22F3/24; C22F1/02; H; H01; H01J; H01J9/00; H01J9/02
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
70 words
The method of making a tungsten electrode comprising the steps of: providing a basic electrode comprising tungsten; then heating said basic electrode in wet hydrogen at about 1050° C. for about 5 to 10 minutes; then further heating said basic electrode at about 1500° C. for about three hours in a vacuum; and then further heating said basic electrode at about 2800° C. for about 5 minutes in a vacuum.
Claim 2
Independent Claim
70 words
The method of making a tungsten electrode comprising the steps of: providing a basic electrode comprising tungsten; then heating said basic electrode in wet hydrogen at about 1050° C. for about 5 to 10 minutes; then further heating said basic electrode at about 1500° C. for about three hours in a vacuum; and then further heating said basic electrode at about 2800° C. for about 5 minutes in a vacuum.
Claim 3
Dependent Claim
49 words
The method of claim 1 wherein said further heating at about 1500° C. for about three hours is in a vacuum of about 2 ×10 -7 Torr, and said further heating at about 2800° C. for about five minutes is in a vacuum of about 1 ×10 -6 Torr.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein said step of providing said basic electrode comprises mixing tungsten powder and thoria powder as constituents of said basic electrode.
Claim 5
Dependent Claim
25 words
The method of claim 3 wherein said step of providing said basic electrode comprises sintering said constituents of said basic electrode at about 2100° C.
Claim 6
Independent Claim
89 words
A method of making a tungsten electrode comprising the steps of: providing a basic electrode comprising tungsten; then heating said basic electrode in wet hydrogen at about 1050° C. for about 5 to 10 minutes; and then heating said basic electrode in a vacuum furnace while firs further heating said basic electrode at about 1500° C. for about three hours in a vacuum and then raising the temperature in said vacuum furnace and further heating said basic electrode at about 2800° C. for about 5 minutes in a vacuum.
Claim 7
Independent Claim
89 words
A method of making a tungsten electrode comprising the steps of: providing a basic electrode comprising tungsten; then heating said basic electrode in wet hydrogen at about 1050° C. for about 5 to 10 minutes; and then heating said basic electrode in a vacuum furnace while firs further heating said basic electrode at about 1500° C. for about three hours in a vacuum and then raising the temperature in said vacuum furnace and further heating said basic electrode at about 2800° C. for about 5 minutes in a vacuum.
Claim 8
Dependent Claim
48 words
The method of claim 5 wherein said heating at about 1500° C. for about three hours is in a vacuum of about 2 ×10 -7 Torr, and said further heating at about 2800° C. for about 5 minutes is in a vacuum of about 1 ×10 -6 Torr.
Claim 9
Dependent Claim
41 words
The method of claim 5 further including the step of depositing said basic electrode within a tungsten crucible after step (2) and wherein said conveying step (3) includes conveying said tungsten crucible and said basic electrode therein into said vacuum furnace.
Claim 10
Dependent Claim
48 words
The method of claim 7 wherein said heating at about 1500° C. for about three hours in in a vacuum of about 2 ×10 -7 Torr, and said further heating at about 2800° C. for about 5 minutes is in a vacuum of about 1 ×10 -6 Torr.
Claim 11
Dependent Claim
26 words
The method of claim 8 wherein said step of providing said basic electrode comprises mixing tungsten powder and thoria powder as constituents of said basic electrode.
Claim 12
Dependent Claim
25 words
The method of claim 9 wherein said step of providing said basic electrode comprises sintering said constituents of said basic electrode at about 2100° C.
Claim 13
Dependent Claim
49 words
An electrode comprising tungsten which has been heated in wet hydrogen at about 1050° C. for about 5 to 10 minutes, then heated at about 1500° C. for about three hours in a vacuum, and then further heated at about 2800° C. for about 5 minutes in a vacuum.
Claim 14
Dependent Claim
49 words
An electrode comprising tungsten which has been heated in wet hydrogen at about 1050° C. for about 5 to 10 minutes, then heated at about 1500° C. for about three hours in a vacuum, and then further heated at about 2800° C. for about 5 minutes in a vacuum.
Claim 15
Dependent Claim
15 words
The electrode of claim 11 comprising a sintered mixture of tungsten powder and thoria powder.
Claim 16
Dependent Claim
10 words
The electrode of claim 12 comprising about 1% thoria powder.
References Cited (Backward Citations)
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