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US4537745A
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Method of producing copper-chromium fusion alloys as contact material for vacuum power switches
Assignee: Siemens AG
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Filing: 1984-01-27
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Granted: 1985-08-27
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Expires: 2004-01-27
Abstract
Abstract A method of producing copper-chromium fusion alloys having a chromium content of at least 25% by mass and at most 60% by mass with a homogeneous macrostructure without lattice defects and without shrink holes or pipes, which can be used as contact material for vacuum power switches with breaking currents exceeding 10kA. According to the invention, during fusing of the starting material to the fusion alloy a superheating to at least 2000° C. is obtained at least in a partial zone of the instantaneous melt volume. Thereafter the melt is cooled at a cooling rate such that no primary Cr precipitation or segregation occurs.
Inventors
- 👤 Heinrich Hassler
- 👤 Reiner Muller
- 👤 Horst Kippenberg
- 👤 Norbert Prolss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:25
CPC Classifications
H; H01; H01H; H01H1/00; H01H1/02; H01H1/0203; H01H1/0206; B; B22; B22F; B22F3/00; B22F3/24; C; C22; C22C; C22C1/00; C22C1/02; B22F2999/00; H01H33/00; H01H33/60; H01H33/66; H01H33/668; H01H33/6683; Y; Y02; Y02P; Y02P10/00; Y02P10/25
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
136 words
In a method of producing copper-chromium fusion alloys having a chromium content of at least 25% by mass and at most 60% by mass with a homogeneous macrostructure without lattice defects and without shrink holes or pipes for use as contact material for vacuum power switches with breaking currents above 10 KA, wherein a starting material is prepared for the fusion process from the alloy components copper and chromium and then a melt is formed from this starting material, the improvement comprising the steps of: (a) superheating at least a partial zone of an instantaneous volume of said melt to at least 2000° C., thereby to fuse the starting material into the fusion alloy; and (b) rapidly cooling the melt at a non-thermodynamic equilibrium rate such that a primary Cr precipitation or segregation does not occur.
Claim 2
Dependent Claim
136 words
In a method of producing copper-chromium fusion alloys having a chromium content of at least 25% by mass and at most 60% by mass with a homogeneous macrostructure without lattice defects and without shrink holes or pipes for use as contact material for vacuum power switches with breaking currents above 10 KA, wherein a starting material is prepared for the fusion process from the alloy components copper and chromium and then a melt is formed from this starting material, the improvement comprising the steps of: (a) superheating at least a partial zone of an instantaneous volume of said melt to at least 2000° C., thereby to fuse the starting material into the fusion alloy; and (b) rapidly cooling the melt at a non-thermodynamic equilibrium rate such that a primary Cr precipitation or segregation does not occur.
Claim 3
Dependent Claim
22 words
The method according to claim 1, wherein the starting material is fused in an arc melting furnace under a shield gas atmosphere.
Claim 4
Dependent Claim
17 words
The method according to claim 1, wherein the starting material is fused by means of electron beams.
Claim 5
Dependent Claim
22 words
The method according to claim 1, wherein the starting material is fused by means of laser beams under a shield gas atmosphere.
Claim 6
Dependent Claim
22 words
The method according to claim 1, wherein the starting material is fused by means of high-frequency plasma under a shield gas atmosphere.
Claim 7
Dependent Claim
21 words
The method according to claim 1, wherein the starting material is prepared by powder-metallurgical methods by pressing of copper-chromium powder mixtures.
Claim 8
Dependent Claim
21 words
The method according to claim 1, wherein the starting material is prepared by powder-metallurgical methods by sintering of copper-chromium powder mixtures.
Claim 9
Dependent Claim
23 words
The method according to claim 1, wherein the starting material is prepared by powder-metallurgical methods by pressing and sintering of copper-chromium powder mixtures.
Claim 10
Dependent Claim
23 words
The method according to claim 1, wherein the starting material is prepared by powder-metallurgical methods by copper infiltration of a sintered chromium skeleton.
Claim 11
Dependent Claim
24 words
The method according to claim 1, wherein the starting material is prepared as composite material from a copper jacket with a chromium powder filling.
Claim 12
Dependent Claim
22 words
The method according to claim 1, wherein the starting material is prepared from a copper bar with bores filled with chromium powder.
Claim 13
Dependent Claim
20 words
The method according to claim 1, wherein the starting material is prepared from a copper rod clad with chromium powder.
Claim 14
Dependent Claim
24 words
The method according to claim 1, further comprising adding to the starting material at most 1% by mass of carbon as a reducing agent.
Claim 15
Dependent Claim
16 words
The method according to claim 2, wherein a rare gas is used as a shield gas.
Claim 16
Dependent Claim
16 words
The method according to claim 4, wherein a rare gas is used as a shield gas.
Claim 17
Dependent Claim
16 words
The method according to claim 5, wherein a rare gas is used as a shield gas.
Claim 18
Dependent Claim
19 words
The method according to claim 14, further comprising adding hydrogen gas to the shield gas as a reducing addition.
Claim 19
Dependent Claim
19 words
The method according to claim 15, further comprising adding hydrogen gas to the shield gas as a reducing addition.
Claim 20
Dependent Claim
19 words
The method according to claim 16, further comprising adding hydrogen gas to the shield gas as a reducing addition.
Claim 21
Dependent Claim
20 words
The method according to claim 14, further comprising adding carbon monoxide gas to the shield gas as a reducing addition.
Claim 22
Dependent Claim
20 words
The method according to claim 15, further comprising adding carbon monoxide gas to the shield gas as a reducing addition.
Claim 23
Dependent Claim
20 words
The method according to claim 16, further comprising adding carbon monoxide gas to the shield gas as a reducing addition.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-26 | 1989-02-25 | 1989-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-26 | 1993-02-25 | 1993-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-26 | 1997-02-25 | 1997-08-27 | $7700.00 | Window Closed / Lapsed |