US3450573A - Grain refinement process for copper-bismuth alloys - Google Patents
Grain refinement process for copper-bismuth alloys Download PDFInfo
- Publication number
- US3450573A US3450573A US556251A US3450573DA US3450573A US 3450573 A US3450573 A US 3450573A US 556251 A US556251 A US 556251A US 3450573D A US3450573D A US 3450573DA US 3450573 A US3450573 A US 3450573A
- Authority
- US
- United States
- Prior art keywords
- copper
- alloy
- bismuth
- extrusion
- grain refinement
- 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 15
- 229910001152 Bi alloy Inorganic materials 0.000 title description 10
- QAAXRTPGRLVPFH-UHFFFAOYSA-N [Bi].[Cu] Chemical compound [Bi].[Cu] QAAXRTPGRLVPFH-UHFFFAOYSA-N 0.000 title description 10
- 229910045601 alloy Inorganic materials 0.000 description 23
- 239000000956 alloy Substances 0.000 description 23
- 238000001125 extrusion Methods 0.000 description 21
- 229910052797 bismuth Inorganic materials 0.000 description 10
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 10
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 9
- 229910052802 copper Inorganic materials 0.000 description 9
- 239000010949 copper Substances 0.000 description 9
- 239000000463 material Substances 0.000 description 6
- 238000005266 casting Methods 0.000 description 3
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 230000002706 hydrostatic effect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000000137 annealing Methods 0.000 description 2
- 238000009924 canning Methods 0.000 description 2
- 239000000356 contaminant Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 235000012438 extruded product Nutrition 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000010309 melting process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/02—Contacts characterised by the material thereof
- H01H1/021—Composite material
- H01H1/025—Composite material having copper as the basic material
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C9/00—Alloys based on copper
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/02—Contacts characterised by the material thereof
- H01H1/0203—Contacts characterised by the material thereof specially adapted for vacuum switches
-
- 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
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S72/00—Metal deforming
- Y10S72/70—Deforming specified alloys or uncommon metal or bimetallic work
-
- 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
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/4981—Utilizing transitory attached element or associated separate material
- Y10T29/49812—Temporary protective coating, impregnation, or cast layer
-
- 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
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49826—Assembling or joining
- Y10T29/49885—Assembling or joining with coating before or during assembling
-
- 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
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/4998—Combined manufacture including applying or shaping of fluent material
- Y10T29/49988—Metal casting
Definitions
- Copper-bismuth alloys with a refined grain structure are prepared by casting the alloys, which contain from 0.05% to 1% of bismuth, into the form of ingots, heating the ingots to temperatures in the range of 300 C. to 950 C., and extruding the heated ingots at an extrusion ratio such that the alloy is maintained in a state of hydrostatic compression during deformation, and that tensile forces are absent, a preferred extrusion ratio being 4:1.
- This invention is concerned with a method of improving the properties of copper-bismuth alloys intended for use in electrical devices, and is particularly concerned with a process for preparing such alloys with a refined grain structure.
- An alloy with anti-welding properties is required at the contact faces of vacuum switches.
- a copper-bismuth alloy is favoured for this purpose, the alloy usually being produced in the cast state by melting processes.
- a drawback of the cast material is the inherently large grain size which may lead to the plucking of pieces of material, corresponding to the large grains, from the contact faces.Such pieces of material may cause restriking, or obstruct reclosure of the switch. This difficulty may be overcome by reducing the grain size of the alloy.
- the usual methods of grain refinement by forging or rolling are not possible with copper-bismuth alloys due to the brittle nature of the material.
- This invention consists in a method of preparing a copper-bismuth alloy with a refined grain structure, which comprises subjecting the alloy to an extrusion process at a temperature in the range 300-950 C., the extrusion ratio being typically 4:1. It is preferable to extrude at a temperature in the lower part of the range.
- Copper-bismuth alloys in the range 0.051% bismuth by weight are melted and cast into ingots by a suitable technique.
- One such technique which has been employed for vacuum switch alloy production, involves high frequency melting in a graphite crucible in a vacuum. In this technique it is necessary to alloy for any loss of the more volatile element bismuth that occurs, to ensure that the desired alloy composition is obtained.
- the ingots from the casting operation are machined to produce billets appropriate for extrusion. Typical billets would be cylindrical, 4" diameter x 6" long. At this stage and before extrusion it may be desirable to enclose the alloy billet in a ductile can.
- the can serves a dual purpose, firstly to give support to the alloy during the extrusion process and also to prevent the pick up of gaseous or other contaminants which are deleterious to the satisfactory functioning of a vacuum switch. It has been found that copper tube forms a suitable canning material for the alloy billet, the ends of the tube being sealed by welded-in copper plugs. The pick-up of gaseous contaminants can be further reduced by evacuating the can before sealing.
- the billet is heated by any appropriate means to the extrusion temperature, which for copper-bismuth alloys lies in the range 300-950 C.
- the heated billet is extruded through a die of the required dimensions. If a cylindrical rod is required, this may be produced by extrusion through a circular die. Alternatively, strip may be obtained by extrusion through a die of rectangular cross section. Various other shapes of extruded product are also possible.
- the canning material extrudes simultaneously with the alloy, maintaining a gas tight sheath on the alloy.
- the sheath is removed by machining.
- Example 1 An alloy cast from copper with 0.5% added bismuth was machined to give a 2" diameter extrusion billets. This was heated to 850 C. and extruded to 1 diameter, i.e., with 4:1 extrusion ratio. The cast grain size of 2-3 mm. was reduced to a fine equiaxed structure with grains mm. diameter by this method.
- Example 2 An alloy of copper with 0.5 bismuth by weight was extruded at 500 C. with a 4:1 extrusion ratio, viz. from a 2" diameter billet to 1" diameter. After extrusion the structure showed elongated grains of copper interspersed with bismuth, demonstrating that at this extrusion temperature the copper retains a worked structure. On annealing the alloy at 800 C. for 1 hour to simulate processing on a vacuum switch the copper phase was annealed and an equiaxed grain structure was produced with grain size 0.2-0.3 mm. compared with the cast grain size of 2-3 mm.
- a method of manufacturing a copper-bismuth alloy with a refined grain structure which includes the steps of casting a copper-bismuth alloy containing 0.05% to 1% bismuth into the form of an ingot, heating the ingot to a temperature in the range of 300 C. to 950 C., and extruding the heated ingot at an extrusion ratio such that the alloy is maintained in a state of hydrostatic compression during deformation and that tensile forces are absent.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Composite Materials (AREA)
- Extrusion Of Metal (AREA)
- Conductive Materials (AREA)
Description
United States Patent U.S. Cl. 148-2 4 Claims ABSTRACT OF THE DISCLOSURE Copper-bismuth alloys with a refined grain structure are prepared by casting the alloys, which contain from 0.05% to 1% of bismuth, into the form of ingots, heating the ingots to temperatures in the range of 300 C. to 950 C., and extruding the heated ingots at an extrusion ratio such that the alloy is maintained in a state of hydrostatic compression during deformation, and that tensile forces are absent, a preferred extrusion ratio being 4:1.
This invention is concerned with a method of improving the properties of copper-bismuth alloys intended for use in electrical devices, and is particularly concerned with a process for preparing such alloys with a refined grain structure.
An alloy with anti-welding properties is required at the contact faces of vacuum switches. A copper-bismuth alloy is favoured for this purpose, the alloy usually being produced in the cast state by melting processes. A drawback of the cast material is the inherently large grain size which may lead to the plucking of pieces of material, corresponding to the large grains, from the contact faces.Such pieces of material may cause restriking, or obstruct reclosure of the switch. This difficulty may be overcome by reducing the grain size of the alloy. The usual methods of grain refinement by forging or rolling are not possible with copper-bismuth alloys due to the brittle nature of the material.
This invention consists in a method of preparing a copper-bismuth alloy with a refined grain structure, which comprises subjecting the alloy to an extrusion process at a temperature in the range 300-950 C., the extrusion ratio being typically 4:1. It is preferable to extrude at a temperature in the lower part of the range.
An important feature of the extrusion process is that the alloy is maintained in a state of hydrostatic compression during deformation, and that tensile forces are absent. Intergranular cracking which normally takes place via the bismuth phase in the alloy is thereby avoided.
The invention is put into practice in the following way. Copper-bismuth alloys in the range 0.051% bismuth by weight are melted and cast into ingots by a suitable technique. One such technique, which has been employed for vacuum switch alloy production, involves high frequency melting in a graphite crucible in a vacuum. In this technique it is necessary to alloy for any loss of the more volatile element bismuth that occurs, to ensure that the desired alloy composition is obtained. The ingots from the casting operation are machined to produce billets appropriate for extrusion. Typical billets would be cylindrical, 4" diameter x 6" long. At this stage and before extrusion it may be desirable to enclose the alloy billet in a ductile can. The can serves a dual purpose, firstly to give support to the alloy during the extrusion process and also to prevent the pick up of gaseous or other contaminants which are deleterious to the satisfactory functioning of a vacuum switch. It has been found that copper tube forms a suitable canning material for the alloy billet, the ends of the tube being sealed by welded-in copper plugs. The pick-up of gaseous contaminants can be further reduced by evacuating the can before sealing.
For extrusion, the billet is heated by any appropriate means to the extrusion temperature, which for copper-bismuth alloys lies in the range 300-950 C. The heated billet is extruded through a die of the required dimensions. If a cylindrical rod is required, this may be produced by extrusion through a circular die. Alternatively, strip may be obtained by extrusion through a die of rectangular cross section. Various other shapes of extruded product are also possible.
The canning material extrudes simultaneously with the alloy, maintaining a gas tight sheath on the alloy. The sheath is removed by machining.
The magnitude of the grain refining effect is shown by the following examples.
Example 1 An alloy cast from copper with 0.5% added bismuth was machined to give a 2" diameter extrusion billets. This was heated to 850 C. and extruded to 1 diameter, i.e., with 4:1 extrusion ratio. The cast grain size of 2-3 mm. was reduced to a fine equiaxed structure with grains mm. diameter by this method.
Example 2 An alloy of copper with 0.5 bismuth by weight was extruded at 500 C. with a 4:1 extrusion ratio, viz. from a 2" diameter billet to 1" diameter. After extrusion the structure showed elongated grains of copper interspersed with bismuth, demonstrating that at this extrusion temperature the copper retains a worked structure. On annealing the alloy at 800 C. for 1 hour to simulate processing on a vacuum switch the copper phase was annealed and an equiaxed grain structure was produced with grain size 0.2-0.3 mm. compared with the cast grain size of 2-3 mm.
What we claim is:
1. A method of manufacturing a copper-bismuth alloy with a refined grain structure, which includes the steps of casting a copper-bismuth alloy containing 0.05% to 1% bismuth into the form of an ingot, heating the ingot to a temperature in the range of 300 C. to 950 C., and extruding the heated ingot at an extrusion ratio such that the alloy is maintained in a state of hydrostatic compression during deformation and that tensile forces are absent.
2. A method according to claim 1, in which the ingot is machined to the form of a cylindrical billet which is 3 then enclosed in a copper tube, the ends of the tube being sealed by welded copper plugs, and the billet is then subjected to the extrusion process, the copper covering being later removed by machining.
3. A method according to claim 1, in which a copperbismuth alloy containing 0.5% bismuth is extruded at a temperature of 850 C., the extrusion ratio being 4:1.
4. A method according to claim 1, in which a copperbismuth alloy containing 0.5% bismuth is extruded at 500 C., the extrusion ratio being 4:1, and the extruded alloy is thereafter subjected to annealing by being heated to 800 C. for one hour.
References Cited UNITED STATES PATENTS 4 2,975,256 3/1961 Lee et a1 200-166 X 3,122,828 3/ 1964 Havel 29-528 X 3,246,979 4/ 1966 Laiferty et a1 75-153 X 5 OTHER REFERENCES Metals, Carpenter and Robertson, Oxford Univ. Press, New York, 1939, relied on pp. 1255-1257.
The Journal of the Institute of Metals, vol. 37, No. 1, 1 1927, relied on pp. 169-478.
CHARLES N. LOVELL, Primary Examiner.
US. Cl. X.R.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB27740/65A GB1078657A (en) | 1965-06-30 | 1965-06-30 | Grain refinement process for copper-bismuth alloys |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3450573A true US3450573A (en) | 1969-06-17 |
Family
ID=10264492
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US556251A Expired - Lifetime US3450573A (en) | 1965-06-30 | 1966-06-09 | Grain refinement process for copper-bismuth alloys |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US3450573A (en) |
| BE (1) | BE683302A (en) |
| CH (1) | CH471898A (en) |
| DE (1) | DE1533499A1 (en) |
| GB (1) | GB1078657A (en) |
| NL (1) | NL6609015A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3805000A (en) * | 1970-03-23 | 1974-04-16 | Itt | Vacuum interrupter and methods of making contacts therefor |
| US4231814A (en) * | 1978-02-22 | 1980-11-04 | Hitachi, Ltd. | Method of producing a vacuum circuit breaker |
| US5167726A (en) * | 1990-05-15 | 1992-12-01 | At&T Bell Laboratories | Machinable lead-free wrought copper-containing alloys |
| CN114101371A (en) * | 2021-11-09 | 2022-03-01 | 中铝洛阳铜加工有限公司 | Processing method of large-caliber thick-wall copper pipe for annular conduction band |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2246328A (en) * | 1939-07-26 | 1941-06-17 | Bell Telephone Labor Inc | Asymmetrical conductor and method of making the same |
| US2379232A (en) * | 1943-11-02 | 1945-06-26 | Mallory & Co Inc P R | Metallic compositions containing bismuth |
| US2975256A (en) * | 1958-07-24 | 1961-03-14 | Gen Electric | Vacuum type circuit interrupter |
| US3122828A (en) * | 1963-01-14 | 1964-03-03 | Special Metals Inc | Conversion of heat-sensitive alloys with aid of a thermal barrier |
| US3246979A (en) * | 1961-11-10 | 1966-04-19 | Gen Electric | Vacuum circuit interrupter contacts |
-
1965
- 1965-06-30 GB GB27740/65A patent/GB1078657A/en not_active Expired
-
1966
- 1966-06-09 US US556251A patent/US3450573A/en not_active Expired - Lifetime
- 1966-06-23 DE DE19661533499 patent/DE1533499A1/en active Pending
- 1966-06-24 CH CH915166A patent/CH471898A/en not_active IP Right Cessation
- 1966-06-28 BE BE683302D patent/BE683302A/xx unknown
- 1966-06-29 NL NL6609015A patent/NL6609015A/xx unknown
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2246328A (en) * | 1939-07-26 | 1941-06-17 | Bell Telephone Labor Inc | Asymmetrical conductor and method of making the same |
| US2379232A (en) * | 1943-11-02 | 1945-06-26 | Mallory & Co Inc P R | Metallic compositions containing bismuth |
| US2975256A (en) * | 1958-07-24 | 1961-03-14 | Gen Electric | Vacuum type circuit interrupter |
| US3246979A (en) * | 1961-11-10 | 1966-04-19 | Gen Electric | Vacuum circuit interrupter contacts |
| US3122828A (en) * | 1963-01-14 | 1964-03-03 | Special Metals Inc | Conversion of heat-sensitive alloys with aid of a thermal barrier |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3805000A (en) * | 1970-03-23 | 1974-04-16 | Itt | Vacuum interrupter and methods of making contacts therefor |
| US4231814A (en) * | 1978-02-22 | 1980-11-04 | Hitachi, Ltd. | Method of producing a vacuum circuit breaker |
| US5167726A (en) * | 1990-05-15 | 1992-12-01 | At&T Bell Laboratories | Machinable lead-free wrought copper-containing alloys |
| CN114101371A (en) * | 2021-11-09 | 2022-03-01 | 中铝洛阳铜加工有限公司 | Processing method of large-caliber thick-wall copper pipe for annular conduction band |
| CN114101371B (en) * | 2021-11-09 | 2023-05-30 | 中铝洛阳铜加工有限公司 | Processing method of large-caliber thick-wall copper pipe for annular conduction band |
Also Published As
| Publication number | Publication date |
|---|---|
| DE1533499A1 (en) | 1970-04-09 |
| GB1078657A (en) | 1967-08-09 |
| CH471898A (en) | 1969-04-30 |
| NL6609015A (en) | 1967-01-02 |
| BE683302A (en) | 1966-12-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5580516A (en) | Powders and products of tantalum, niobium and their alloys | |
| US3807969A (en) | Aluminum alloy electrical conductor | |
| KR20020028890A (en) | Copper sputtering target assembly and method of making same | |
| EP0098996A1 (en) | Zirconium alloy having superior corrosion resistance | |
| US2666721A (en) | Process of producing ductile molybdenum | |
| US3450573A (en) | Grain refinement process for copper-bismuth alloys | |
| US4082573A (en) | High tensile strength aluminum alloy conductor and method of manufacture | |
| RU2771342C1 (en) | METHOD FOR PRODUCING LONG-LENGTH SEMI-FINISHED PRODUCTS FROM TiNiHf ALLOYS WITH HIGH-TEMPERATURE SHAPE MEMORY EFFECT | |
| US4059437A (en) | Oxygen-free copper product and process | |
| CA1045009A (en) | Process for producing copper base alloys | |
| JPH0238652B2 (en) | ||
| US3920411A (en) | Aluminum alloy electrical conductor and method for making same | |
| US4906291A (en) | Method for manufacturing melt materials of copper, chromium, and at least one readily evaporable component using a fusible electrode | |
| US3907550A (en) | Method of making same composite billets | |
| EP1826284A1 (en) | Case made of magnesium alloy | |
| US3019102A (en) | Copper-zirconium-hafnium alloys | |
| JPS6333563A (en) | Production of pt-ni alloy for sputtering | |
| US2795520A (en) | Extruded phosphorus-silver-copper brazing alloys | |
| GB2055398A (en) | Electrical contact materials of internally oxidized Ag-Sn-Bi alloy | |
| KR960001714B1 (en) | Method of casting and mold making | |
| US3341321A (en) | Process for treating primarily metallic materials | |
| US4231814A (en) | Method of producing a vacuum circuit breaker | |
| EP0408469B1 (en) | Copper-iron-cobalt-titanium alloy featuring high mechanical and electrical properties and process for the manufacture thereof | |
| GB2093066A (en) | Electrical contact material | |
| US4102709A (en) | Workable nickel alloy and process for making same |