CA1126056A - Copper-nickel-silicon-chromium alloy having improved electrical conductivity - Google Patents
Copper-nickel-silicon-chromium alloy having improved electrical conductivityInfo
- Publication number
- CA1126056A CA1126056A CA339,297A CA339297A CA1126056A CA 1126056 A CA1126056 A CA 1126056A CA 339297 A CA339297 A CA 339297A CA 1126056 A CA1126056 A CA 1126056A
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- CA
- Canada
- Prior art keywords
- alloy
- excess
- silicon
- chromium
- temperature
- 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.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/06—Halogens; Compounds thereof
- B01J27/08—Halides
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/08—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of copper or alloys based thereon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/222—Non-consumable electrodes
Abstract
Abstract of the Disclosure A copper-nickel-silicon-chromium alloy having a high hardness and improved electrical conductivity. The alloy is composed by weight of 2.0% to 3.0% nickel, 0.4% to 0.5% silicon, 0.1% to 0.5% chromium, and the balance copper. The silicon is used in excess of the stoichiometric relationship wtih nickel to provide excess silicon, and the chromium is used in excess of the stoichiometric relationship with the excess silicon.
The alloy is heat treated by initially heating the alloy to a temperature in the range of 1600°F to 1800°F and is thereafter quenched. The quenched alloy is then subjected to a two-step aging treatment in which the alloy is initially aged at a temperature of 482°C to 593°C to precipitate the metal silic-ides and develop a hardness in excess of 90 Rockwell B (185 Brinell) and subsequently is subjected to a second aging at a temperature in the range of 399°C to 482°C, which serves to precipitate the excess chromium from solution and increase the electrical conductivity to a value greater than 45%.
The alloy is heat treated by initially heating the alloy to a temperature in the range of 1600°F to 1800°F and is thereafter quenched. The quenched alloy is then subjected to a two-step aging treatment in which the alloy is initially aged at a temperature of 482°C to 593°C to precipitate the metal silic-ides and develop a hardness in excess of 90 Rockwell B (185 Brinell) and subsequently is subjected to a second aging at a temperature in the range of 399°C to 482°C, which serves to precipitate the excess chromium from solution and increase the electrical conductivity to a value greater than 45%.
Description
5~
Background of the Invention In industry and commerce there is need for rnetals of good hardness with good conductivity. These -two properties are quite incongruous since good conductivity is a property of pure metals whereas good hardness is normally achieved by alloyina the pure metal with one or more metals.
Copper and silver are the two metals that exhibit the highest electrical and thermal conductivity. Silver has e~cellent conductivity, but is soft and very expensive. Copper, although relatively expensive, is widely used where high con-ductivity is necessary and is, in fact, the standard used in rating the conductiT- ty of other metals. However, copper is comparatively soft in its pure state, and to strengthen copper and increase its hardness, it mus-t ei-ther be cold worked or alloying elements must be added. Cold working does not reduce the conductivity, but if the application is such that the copper i5 subsequently heated, the properties ohtained by cold working can be lost. ~dding alloying elements to copper reduces the conductivity to significantly low levels, dependlng upon -the specific element and quantity used.
Brasses and bronzes, of which there are many kinds, are copper base alloys to which, singly or in com~ination, such elements as tin, zinc, aluminum, iron, etc., have been added for strength. Such additions seriously reduce the electrical and thermal conductivity. For example, when added singly to pure copper, as little as 0.1% of nickel, aluminum or tin will reduce the 100% electrical condwctivity o~ p~lre copper to 94%, 91% and 99%, respectively, and a 1% addition of these elements will drop the conductivity to less than 50%. As little as 0.1% silicon or phosphorous will reduce the electrical vs~
conductivity of copper a-t least 50%, ~7ith little or no significant improvement in strength or hardness.
Certain elements have a varying degree of solid solub-ility in copper, which changes with temperature. ~his makes possible the wel] known age or precipitation hardened alloys.
United States Patent to Corson 1,658,186 was an early pioneer in the discovery of the age of precipitation hardening phenomenon in copper base alloys. The basic concept was one in which he folmd that certain elements could be put in~o solid solution in selected copper alloys by heating the metal to an elevated temperature, ollowed by rapid cooling in a ~uenching media. Then, by reheating to a selected lower ternperature for various periods of time, he found that specific metallic compounds could be precipitated out of the solid solution. The effect oE this treatment served two purposes. ~irst, the alloying elements precipitated out of I solid solution are in the form of discrete particles, which increased the strength and hardness by interfering with the normal mode of physical deforntation of the metal under stress.
Secondly, it increased the electrical conductivity of the alloy through the effective removal of alloying elements ~hich were precipitated from the copper matrix.
More particularly, the United States Patent 1,658,186 describes copper alloys containing silicon, and one or more of a group of silicide forming elements, specifically chromium, cobalt and nickel. In accordance with the Corson invention, improved hardness is achieved b~ a heat treatment consisting of heating the alloys to a tentperature in the range of 750C
to 975C and subse~uently ~uenching the alloy to hold the bulk of the alloying elements in solid solution. After ~uenching, the Corson alloys are aged at a temperature in 6~S~i the range of 250C to 600C ~482F to 1112F) to precipitate the metallic silicides resulting in an increase in hardness with improvement in electrical conductivity.
As described in the Corson patent, several classes of alloys were produced, including (1) an alloy having an electrical conductivity of 35% and a hardness of 150 Brinell; (2) an alloy of 55% conductivity with a minimum hardness of 135 Brinell;
and (3) an alloy with 75~ conductivity with a minimum hardness of 110 Brinell. The Corson alloys have never achieved significant commercial importance where both high hardness and high conductivity are required, as in the case of resistance welding electrodes.
In resistance welding of metals, the spot welding tips or contact materials must have good hardness and strength to hold their shape and they must be able to conduct sufficient electrical current to make the weld without undue heating of the contact material, which would cause softening and deformation.
The one common alloy used for resistance welding of stainless steel, is identified by the Resistance Welding Manufacturing Association as the Class 3 type. The specifica-tion for this alloy calls for a minimum electrical conductivity of 45~ of the conductivity of pure copper, with a minimum hard-ness of 90 Rockwell B (185 Brinellj. The alloy that has been commonly used contains beryllium, the vapors of which have been identified as being toxic. The copper-beryllium alloy must be melted only under the strictest vapor control, and fine grinding dust must be completely collected in the work area. These restrictions have reduced the number of suppliers, and greatly increased the production cost.
, Summary of the Invention The invention is directed to a copper-nickel-silicon-chromium alloy having a high degree of hardness, along with improved electrical conductivity, above 45~.
The alloy i5 COlllpOSed of a total weight of 2.0% to 3.0~
nickel and/or cobalt, 0.4~ to 0.8% silicon, 0.1% to 0.5% chromium, and the balance copper. In the alloy of the invention, cobalt can be substituted in whole or in part for the nickel, although the total elimination of nickel can cause some depreciation in mechanical properties.
To provide the desired high hardness and strength along with high electrical conductivity, it is necessary to employ specific weight ratios between the nickel and/or cobalt, the silicon and chromium. The silicon is used in an amount slightly in excess of the stoichiometric amount necessary to form silicides of the nic]~el and/or cobalt, thereby removing the nickel and/or cobalt from solution as Ni2Si and leaving excess silicon.
The chromium is used in an amount slightly greater 20 than the stoichiometric amount required to form chromium silicide Cr3Si or Cr5Si3 with the excess silicon. Because of the low solubility of chromium in copper, the excess chromium will be precipitated by a second aging treatment.
The desired hardness is achieved by a precipitation 25 hardening treatment in which the alloy is initially heated to a solution temperature in the range of 871C to 982C and quenched to room temperature in water or other suitable mediaO
The alloy is then reheated to a temperature in the range of 482C to 593C to allow the precipitation of silicides and 30 develop a hardness in excess of 90 Rockwell B(185 Brinell) and an electrical conductivity in the range of 35~ to 40~.
~4--~2~5~ii The alloy is then subjected to a second aging treatment by heating -to a temperature in the range of 399C to ~82~C, and at this temperature the excess chromium, over and above that necessary to form chromium s.ilicide, is preciptiated to thereby improve the electrical conductivity of the alloy to values greater than 45~. -: As an alternate procedure, the alloy can be subjected to controlled furnace cooling from the first aging temperature down to the second aging temperature and holding the alloy at the second aging temperature for a period of time sufficientto develop the required electrical conductivity.
The alloy of the invention has a high degree of hard-ness and strength and also has a high electrical conductivity of over 45%. This is achieved by the controlled additions of the alloying elements, and the double aginy heat treatment.
Description of the Preferred Embodiment . The alloy of the invention has the following composi-tion in weight percent:
Nickel or Cobalt or2 0 - 3 0~
mixtures thereof Silicon 0.4 - 0.8%
Chromium 0.1 - 0.5%
Balance Copper It is preferred that the silicon content be equal to, or preferably, slight~y in excess, of the s-toichiometric amount required to form the nickel and/or cobalt silicides during the first aging treatment and ensure that substantially all of the nickel and/or cobalt is removed from the solid solution as Ni2Si or Co2Si, and leaving excess silicon. For example, the silicon content should be sliyhtly in excess of the nickel content divided by 4.18. If cobalt is used in place of nickel, l~Z~
the silicon content should be slightly in excess of the cobalt content divided by 4.19. If the silicon content falls below the stoichiometric relationship with nickel and/or cobalt, the excess nickel and/or cobalt will remain in solution and reduce the electrical conductivity oE the alloy. ~s it is difficult in practice to utilize precise stoichiometric amounts, it is preferred to use a slight excess of silicon over the stoichio-metric relationship to inure the complete removal of nickel and/or cobalt as the silicides.
The chromium is used in an amount slightly greater than the stoichiometric amount required to form chromium silicide, Cr3Si or Cr5Si3, with the excess silicon. As chromium has a low solubility in copper, the excess chromium will be precipitated by the second aging treatment.
In practising the invention, nickel and silicon are added to a pure copper melt in the ratio of Ni2Si, or 4.18 parts of nickel to one part silicon. A small additional amount of silicon, over the 4.18 ratio, is also added. In accordance with the law of mass action, this excess silicon serves to force the removal of more nickel from solution as Ni2Si during heat treatment, than possible is less than, or only, the exact 4.18 stoichiometric amount is added.
While the excess silicon is important to assure the precipitation of the nickel, it would be very detrimental to the conductivity to retain the silicon in solution. Thus, by utilizing sufficient chromium in the melt, a means is provided to tie up the excess silicon as a chromium silicide, either Cr3Si or CR5Si3. l'here is some latitude in the chromium addi-tion, because of the low solubility of chromium in copper, with the excess chromium being precipitated from the copper matrix by a second aging treatment.
5~
The all~y is heat treated by initially heating to a solution ternperature in the range of 871C to 98ZC . The alloy is held at temperature -for 1 to 3 hours, to ensure a substantially solid solution of the alloying elements in the copper mat.rix.
Subsec~uently, the alloy is quenched to retain the alloying elements in solid solution.
Following this quench, the alloy is aged at a tem-perature in the range of ~2C to 593C and maintained at this temperature for a period of about 1 to 5 hours and prefer-ably about 3 hours. During this aging treatment, the metal silicides precipitate as sub-microscopic particles which increases the hardness of the alloy to a value in excess of 90 Rockwell B (18S Brinell) and the elctrical conauctivity to a value o~ 35~ to 40%.
The alloy is cooled to under 399C and then is sub-jected to a second aging treatment in the range of 399~C to 482~ and preferably at a temperature of 454C The alloy is maintained at the second aging temperature for a period of 1 to 5 hours, and preferably about 3 hours. During the second aging treatment, the excess chromium, over and above that required to form chromium silicides, is precipitated out of solution and the electrical conductivity of the alloy is significantly increased to a value in excess of 45%, and generally in the range of 45% to 50% with no detrimental effect on mechanical properties.
As an alternate to the two-step aging process, a controlled furnace cooling treatment can be used. In the alternate method, the alloy, after quenching from the solu-tion temperature, is heated to an aging temperature in the ~z~s~
range of 510C to 566~C and held at this temperature for aperiod of 1 to 3 hours. The alloy is then furnace cooled to a temperature in the range of ~27C to 454C and held at this latter temperature for a period of about 1/2 to 2 hours. The alloy is then cooled to room temperature. This alternate pro-cess, in which the alloy urnace cools from the first aging temperature to the second aging temperature, is generally not as acceptable in commercial practice as the two-step aging process previously described,;and must be strictly monitored because the rate of cooling depends on the relative mass of the furnace and of the product, and the nature of the furnace insulation.
The following examples illustrate the method of the invention.
EXAMPLE
. _ A copper base alloy having the following analysis in weight percent:
Nickel 2.62%
Silicon 0.64%
Chromium 0O32%
Copper Balance was heated to a solution temperature of 927C and held at this temperature for 1 hour. The alloy was then quenched to room temperature and subsequently aged at 510C for three hours to precipitate the metal silicides. After the aging, the alloy had a Rockwell B hardness of 97 (222 Brinell~ ana an elec-trical conductivity of 38%.
Following the a~iny, the alloy was air cooled to room temperature and subjected to a second aging at 45~C for three hours and subsequently air cooled.
~2~;~56 The resulting alloy had a Rockwell B hardness of 97 (222 Brinell) and an electrical conductivity of 47%.
EXAMPLE III
An alloy having the following analysis:
Nickel 2.85~
Silicon 0.75%
Chromium 0.35%
Copper Balance was heated to a solution temperature of 927C and held at this temperature for 1 hour. The alloy was then quenched in water to room temperature and subsequently heated to an aging temperature of 566C , held at this temperature for 1 hour, and then furnace cooled to 427C for a period of 1-1/2 hours and held at this temperature for 3/4 hour. The alloy was then air cooled to room temperature. After the heat treatment the alloy had a Rockwell B hardness of 95 (210 Brinell) and an electrical conductivity of 47~. ~
The copper base alloy of the invention, through the heat treatment, has a high degree of hardness, above 90 Rockwell B (185 Brinell), along with a high electrical conductivity of over 45%. The invention can be practiced on either cast or wrought material. The alloy has particular application in the form of resistance welding electrodes but would find general use where the combination of high mechanical properties and good conductivity would enhance performance or meet engineering design criteria.
Background of the Invention In industry and commerce there is need for rnetals of good hardness with good conductivity. These -two properties are quite incongruous since good conductivity is a property of pure metals whereas good hardness is normally achieved by alloyina the pure metal with one or more metals.
Copper and silver are the two metals that exhibit the highest electrical and thermal conductivity. Silver has e~cellent conductivity, but is soft and very expensive. Copper, although relatively expensive, is widely used where high con-ductivity is necessary and is, in fact, the standard used in rating the conductiT- ty of other metals. However, copper is comparatively soft in its pure state, and to strengthen copper and increase its hardness, it mus-t ei-ther be cold worked or alloying elements must be added. Cold working does not reduce the conductivity, but if the application is such that the copper i5 subsequently heated, the properties ohtained by cold working can be lost. ~dding alloying elements to copper reduces the conductivity to significantly low levels, dependlng upon -the specific element and quantity used.
Brasses and bronzes, of which there are many kinds, are copper base alloys to which, singly or in com~ination, such elements as tin, zinc, aluminum, iron, etc., have been added for strength. Such additions seriously reduce the electrical and thermal conductivity. For example, when added singly to pure copper, as little as 0.1% of nickel, aluminum or tin will reduce the 100% electrical condwctivity o~ p~lre copper to 94%, 91% and 99%, respectively, and a 1% addition of these elements will drop the conductivity to less than 50%. As little as 0.1% silicon or phosphorous will reduce the electrical vs~
conductivity of copper a-t least 50%, ~7ith little or no significant improvement in strength or hardness.
Certain elements have a varying degree of solid solub-ility in copper, which changes with temperature. ~his makes possible the wel] known age or precipitation hardened alloys.
United States Patent to Corson 1,658,186 was an early pioneer in the discovery of the age of precipitation hardening phenomenon in copper base alloys. The basic concept was one in which he folmd that certain elements could be put in~o solid solution in selected copper alloys by heating the metal to an elevated temperature, ollowed by rapid cooling in a ~uenching media. Then, by reheating to a selected lower ternperature for various periods of time, he found that specific metallic compounds could be precipitated out of the solid solution. The effect oE this treatment served two purposes. ~irst, the alloying elements precipitated out of I solid solution are in the form of discrete particles, which increased the strength and hardness by interfering with the normal mode of physical deforntation of the metal under stress.
Secondly, it increased the electrical conductivity of the alloy through the effective removal of alloying elements ~hich were precipitated from the copper matrix.
More particularly, the United States Patent 1,658,186 describes copper alloys containing silicon, and one or more of a group of silicide forming elements, specifically chromium, cobalt and nickel. In accordance with the Corson invention, improved hardness is achieved b~ a heat treatment consisting of heating the alloys to a tentperature in the range of 750C
to 975C and subse~uently ~uenching the alloy to hold the bulk of the alloying elements in solid solution. After ~uenching, the Corson alloys are aged at a temperature in 6~S~i the range of 250C to 600C ~482F to 1112F) to precipitate the metallic silicides resulting in an increase in hardness with improvement in electrical conductivity.
As described in the Corson patent, several classes of alloys were produced, including (1) an alloy having an electrical conductivity of 35% and a hardness of 150 Brinell; (2) an alloy of 55% conductivity with a minimum hardness of 135 Brinell;
and (3) an alloy with 75~ conductivity with a minimum hardness of 110 Brinell. The Corson alloys have never achieved significant commercial importance where both high hardness and high conductivity are required, as in the case of resistance welding electrodes.
In resistance welding of metals, the spot welding tips or contact materials must have good hardness and strength to hold their shape and they must be able to conduct sufficient electrical current to make the weld without undue heating of the contact material, which would cause softening and deformation.
The one common alloy used for resistance welding of stainless steel, is identified by the Resistance Welding Manufacturing Association as the Class 3 type. The specifica-tion for this alloy calls for a minimum electrical conductivity of 45~ of the conductivity of pure copper, with a minimum hard-ness of 90 Rockwell B (185 Brinellj. The alloy that has been commonly used contains beryllium, the vapors of which have been identified as being toxic. The copper-beryllium alloy must be melted only under the strictest vapor control, and fine grinding dust must be completely collected in the work area. These restrictions have reduced the number of suppliers, and greatly increased the production cost.
, Summary of the Invention The invention is directed to a copper-nickel-silicon-chromium alloy having a high degree of hardness, along with improved electrical conductivity, above 45~.
The alloy i5 COlllpOSed of a total weight of 2.0% to 3.0~
nickel and/or cobalt, 0.4~ to 0.8% silicon, 0.1% to 0.5% chromium, and the balance copper. In the alloy of the invention, cobalt can be substituted in whole or in part for the nickel, although the total elimination of nickel can cause some depreciation in mechanical properties.
To provide the desired high hardness and strength along with high electrical conductivity, it is necessary to employ specific weight ratios between the nickel and/or cobalt, the silicon and chromium. The silicon is used in an amount slightly in excess of the stoichiometric amount necessary to form silicides of the nic]~el and/or cobalt, thereby removing the nickel and/or cobalt from solution as Ni2Si and leaving excess silicon.
The chromium is used in an amount slightly greater 20 than the stoichiometric amount required to form chromium silicide Cr3Si or Cr5Si3 with the excess silicon. Because of the low solubility of chromium in copper, the excess chromium will be precipitated by a second aging treatment.
The desired hardness is achieved by a precipitation 25 hardening treatment in which the alloy is initially heated to a solution temperature in the range of 871C to 982C and quenched to room temperature in water or other suitable mediaO
The alloy is then reheated to a temperature in the range of 482C to 593C to allow the precipitation of silicides and 30 develop a hardness in excess of 90 Rockwell B(185 Brinell) and an electrical conductivity in the range of 35~ to 40~.
~4--~2~5~ii The alloy is then subjected to a second aging treatment by heating -to a temperature in the range of 399C to ~82~C, and at this temperature the excess chromium, over and above that necessary to form chromium s.ilicide, is preciptiated to thereby improve the electrical conductivity of the alloy to values greater than 45~. -: As an alternate procedure, the alloy can be subjected to controlled furnace cooling from the first aging temperature down to the second aging temperature and holding the alloy at the second aging temperature for a period of time sufficientto develop the required electrical conductivity.
The alloy of the invention has a high degree of hard-ness and strength and also has a high electrical conductivity of over 45%. This is achieved by the controlled additions of the alloying elements, and the double aginy heat treatment.
Description of the Preferred Embodiment . The alloy of the invention has the following composi-tion in weight percent:
Nickel or Cobalt or2 0 - 3 0~
mixtures thereof Silicon 0.4 - 0.8%
Chromium 0.1 - 0.5%
Balance Copper It is preferred that the silicon content be equal to, or preferably, slight~y in excess, of the s-toichiometric amount required to form the nickel and/or cobalt silicides during the first aging treatment and ensure that substantially all of the nickel and/or cobalt is removed from the solid solution as Ni2Si or Co2Si, and leaving excess silicon. For example, the silicon content should be sliyhtly in excess of the nickel content divided by 4.18. If cobalt is used in place of nickel, l~Z~
the silicon content should be slightly in excess of the cobalt content divided by 4.19. If the silicon content falls below the stoichiometric relationship with nickel and/or cobalt, the excess nickel and/or cobalt will remain in solution and reduce the electrical conductivity oE the alloy. ~s it is difficult in practice to utilize precise stoichiometric amounts, it is preferred to use a slight excess of silicon over the stoichio-metric relationship to inure the complete removal of nickel and/or cobalt as the silicides.
The chromium is used in an amount slightly greater than the stoichiometric amount required to form chromium silicide, Cr3Si or Cr5Si3, with the excess silicon. As chromium has a low solubility in copper, the excess chromium will be precipitated by the second aging treatment.
In practising the invention, nickel and silicon are added to a pure copper melt in the ratio of Ni2Si, or 4.18 parts of nickel to one part silicon. A small additional amount of silicon, over the 4.18 ratio, is also added. In accordance with the law of mass action, this excess silicon serves to force the removal of more nickel from solution as Ni2Si during heat treatment, than possible is less than, or only, the exact 4.18 stoichiometric amount is added.
While the excess silicon is important to assure the precipitation of the nickel, it would be very detrimental to the conductivity to retain the silicon in solution. Thus, by utilizing sufficient chromium in the melt, a means is provided to tie up the excess silicon as a chromium silicide, either Cr3Si or CR5Si3. l'here is some latitude in the chromium addi-tion, because of the low solubility of chromium in copper, with the excess chromium being precipitated from the copper matrix by a second aging treatment.
5~
The all~y is heat treated by initially heating to a solution ternperature in the range of 871C to 98ZC . The alloy is held at temperature -for 1 to 3 hours, to ensure a substantially solid solution of the alloying elements in the copper mat.rix.
Subsec~uently, the alloy is quenched to retain the alloying elements in solid solution.
Following this quench, the alloy is aged at a tem-perature in the range of ~2C to 593C and maintained at this temperature for a period of about 1 to 5 hours and prefer-ably about 3 hours. During this aging treatment, the metal silicides precipitate as sub-microscopic particles which increases the hardness of the alloy to a value in excess of 90 Rockwell B (18S Brinell) and the elctrical conauctivity to a value o~ 35~ to 40%.
The alloy is cooled to under 399C and then is sub-jected to a second aging treatment in the range of 399~C to 482~ and preferably at a temperature of 454C The alloy is maintained at the second aging temperature for a period of 1 to 5 hours, and preferably about 3 hours. During the second aging treatment, the excess chromium, over and above that required to form chromium silicides, is precipitated out of solution and the electrical conductivity of the alloy is significantly increased to a value in excess of 45%, and generally in the range of 45% to 50% with no detrimental effect on mechanical properties.
As an alternate to the two-step aging process, a controlled furnace cooling treatment can be used. In the alternate method, the alloy, after quenching from the solu-tion temperature, is heated to an aging temperature in the ~z~s~
range of 510C to 566~C and held at this temperature for aperiod of 1 to 3 hours. The alloy is then furnace cooled to a temperature in the range of ~27C to 454C and held at this latter temperature for a period of about 1/2 to 2 hours. The alloy is then cooled to room temperature. This alternate pro-cess, in which the alloy urnace cools from the first aging temperature to the second aging temperature, is generally not as acceptable in commercial practice as the two-step aging process previously described,;and must be strictly monitored because the rate of cooling depends on the relative mass of the furnace and of the product, and the nature of the furnace insulation.
The following examples illustrate the method of the invention.
EXAMPLE
. _ A copper base alloy having the following analysis in weight percent:
Nickel 2.62%
Silicon 0.64%
Chromium 0O32%
Copper Balance was heated to a solution temperature of 927C and held at this temperature for 1 hour. The alloy was then quenched to room temperature and subsequently aged at 510C for three hours to precipitate the metal silicides. After the aging, the alloy had a Rockwell B hardness of 97 (222 Brinell~ ana an elec-trical conductivity of 38%.
Following the a~iny, the alloy was air cooled to room temperature and subjected to a second aging at 45~C for three hours and subsequently air cooled.
~2~;~56 The resulting alloy had a Rockwell B hardness of 97 (222 Brinell) and an electrical conductivity of 47%.
EXAMPLE III
An alloy having the following analysis:
Nickel 2.85~
Silicon 0.75%
Chromium 0.35%
Copper Balance was heated to a solution temperature of 927C and held at this temperature for 1 hour. The alloy was then quenched in water to room temperature and subsequently heated to an aging temperature of 566C , held at this temperature for 1 hour, and then furnace cooled to 427C for a period of 1-1/2 hours and held at this temperature for 3/4 hour. The alloy was then air cooled to room temperature. After the heat treatment the alloy had a Rockwell B hardness of 95 (210 Brinell) and an electrical conductivity of 47~. ~
The copper base alloy of the invention, through the heat treatment, has a high degree of hardness, above 90 Rockwell B (185 Brinell), along with a high electrical conductivity of over 45%. The invention can be practiced on either cast or wrought material. The alloy has particular application in the form of resistance welding electrodes but would find general use where the combination of high mechanical properties and good conductivity would enhance performance or meet engineering design criteria.
Claims (7)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:-
1. A copper base alloy, consisting essentially by weight of 2.0% to 3.0% of a metal selected from the group consisting of nickel and cobalt and mixtures thereof, from 0.4% to 0.8% by weight of silicon, said silicon being present in an amount in excess of the stoichiometric amount required to form silicides of said metal, from 0.1% to 0.5% by weight of chromium, said chromium being present in an amount in excess of the stoichiometric amount required to form chromium silicide with the excess silicon not combined as said metal silicides, and the balance copper, the excess chromium being present as precipitiated particles in the copper matrix, said alloy having an electrical conductivity in excess of 45% of pure copper.
2. The alloy of claim 1, wherein said alloy has a hardness greater than 90 Rockwell B.
3. A method of heating a copper base alloy, consisting essentially by weight of 2.0% to 3.0% of a metal selected from the group consisting of nickel and cobalt and mixtures thereof, from 0.4% to 0.8% by weight of silicon, said silicon being present in an amount in excess of the stoichiometric amount necessary to form silicides of said metal, from 0.1% to 0.5% by weight of chromium, said chromium being present in an amount in excess of the stoichiometric amount required to form chromium silicide with the excess silicon not combined as said metal silicides, and the balance copper, comprising the steps of heating the alloy to a solu-tion temperature, quenching the alloy, aging the alloy at a first aging temperature in the range of 482°C to 593°C for a period of time sufficient to precipitate silicides, and
3. A method of heating a copper base alloy, consisting essentially by weight of 2.0% to 3.0% of a metal selected from the group consisting of nickel and cobalt and mixtures thereof, from 0.4% to 0.8% by weight of silicon, said silicon being present in an amount in excess of the stoichiometric amount necessary to form silicides of said metal, from 0.1% to 0.5% by weight of chromium, said chromium being present in an amount in excess of the stoichiometric amount required to form chromium silicide with the excess silicon not combined as said metal silicides, and the balance copper, comprising the steps of heating the alloy to a solu-tion temperature, quenching the alloy, aging the alloy at a first aging temperature in the range of 482°C to 593°C for a period of time sufficient to precipitate silicides, and
Claim 3 cont'd. . . . . .
aging the alloy at a second aging temperature in the range of 399°C to 482°C for a period of time sufficient to pre-cipitate the excess chromium from solution and increase the electrical conductivity of the alloy to a value in excess of 45%.
aging the alloy at a second aging temperature in the range of 399°C to 482°C for a period of time sufficient to pre-cipitate the excess chromium from solution and increase the electrical conductivity of the alloy to a value in excess of 45%.
4. The method of claim 3, wherein the alloy is held at the first aging temperature for a period of time sufficient to develop a hardness greater than 90 Rockwell B.
5. The method of claim 3, wherein the solution temperature is in the range of 871°C to 982°C and the alloy is held at said solution temperature for a period of 1 to 3 hours, is held at said first aging temperature for a period of 1 to 5 hours and is held at the second aging temperature for a period of l to 5 hours.
6. The method of claim 3, and including the step of cooling the alloy from the first aging temperature to a temperature below 399°C and then reheating the alloy to said second aging temperature.
7. The method of claim 3, and including the step of furnace cooling the alloy from said first aging temperature to said second aging temperature.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US11110 | 1979-02-12 | ||
| US06/011,110 US4191601A (en) | 1979-02-12 | 1979-02-12 | Copper-nickel-silicon-chromium alloy having improved electrical conductivity |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1126056A true CA1126056A (en) | 1982-06-22 |
Family
ID=21748933
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA339,297A Expired CA1126056A (en) | 1979-02-12 | 1979-11-06 | Copper-nickel-silicon-chromium alloy having improved electrical conductivity |
Country Status (16)
| Country | Link |
|---|---|
| US (1) | US4191601A (en) |
| JP (1) | JPS5937340B2 (en) |
| KR (2) | KR880000766B1 (en) |
| AT (1) | AT370445B (en) |
| AU (1) | AU530377B2 (en) |
| BE (1) | BE879035A (en) |
| CA (1) | CA1126056A (en) |
| CH (1) | CH648598A5 (en) |
| DE (1) | DE2942345A1 (en) |
| ES (1) | ES485022A1 (en) |
| FI (1) | FI69875C (en) |
| FR (1) | FR2448578A1 (en) |
| GB (1) | GB2043690B (en) |
| IT (1) | IT1164838B (en) |
| NL (1) | NL7907272A (en) |
| SE (1) | SE440669B (en) |
Families Citing this family (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4338130A (en) * | 1980-11-20 | 1982-07-06 | Burkett Richard A | Precipitation hardening copper alloys |
| JPS58124254A (en) * | 1982-01-20 | 1983-07-23 | Nippon Mining Co Ltd | Copper alloy for lead material of semiconductor device |
| JPS6058783B2 (en) * | 1982-01-20 | 1985-12-21 | 日本鉱業株式会社 | Method for manufacturing copper alloy for lead material of semiconductor equipment |
| JPS5949293B2 (en) | 1982-06-05 | 1984-12-01 | 株式会社神戸製鋼所 | Copper alloy for electrical and electronic parts and its manufacturing method |
| US4728372A (en) * | 1985-04-26 | 1988-03-01 | Olin Corporation | Multipurpose copper alloys and processing therefor with moderate conductivity and high strength |
| US4594221A (en) * | 1985-04-26 | 1986-06-10 | Olin Corporation | Multipurpose copper alloys with moderate conductivity and high strength |
| US5020770A (en) * | 1988-05-12 | 1991-06-04 | Moberg Clifford A | Combination of mold and alloy core pin |
| US5028391A (en) * | 1989-04-28 | 1991-07-02 | Amoco Metal Manufacturing Inc. | Copper-nickel-silicon-chromium alloy |
| US4950154A (en) * | 1989-07-03 | 1990-08-21 | Moberg Clifford A | Combination injection mold and sprue bushing |
| FR2706488B1 (en) * | 1993-06-14 | 1995-09-01 | Tech Ind Fonderie Centre | Copper, nickel, silicon and chromium alloy and process for the preparation of said alloy. |
| JP2807398B2 (en) * | 1993-08-03 | 1998-10-08 | 和明 深道 | Magnetoresistance effect material, method of manufacturing the same, and magnetoresistance element |
| US6764556B2 (en) | 2002-05-17 | 2004-07-20 | Shinya Myojin | Copper-nickel-silicon two phase quench substrate |
| US7182823B2 (en) * | 2002-07-05 | 2007-02-27 | Olin Corporation | Copper alloy containing cobalt, nickel and silicon |
| KR20040014756A (en) * | 2002-08-12 | 2004-02-18 | 김동원 | Filament Winding Machine |
| KR100497817B1 (en) * | 2002-11-27 | 2005-07-01 | 김조권 | A lightweight multi-stage electric pole and manufacturing method and device |
| KR100516441B1 (en) * | 2002-11-28 | 2005-09-23 | 김조권 | Centrifugal manufacturing method and device of filament wind |
| KR20040051758A (en) * | 2002-12-13 | 2004-06-19 | 최선영 | Large size pipe shape manufacture method and the device |
| JP4494258B2 (en) * | 2005-03-11 | 2010-06-30 | 三菱電機株式会社 | Copper alloy and manufacturing method thereof |
| US8317948B2 (en) * | 2005-03-24 | 2012-11-27 | Jx Nippon Mining & Metals Corporation | Copper alloy for electronic materials |
| US20110038753A1 (en) * | 2007-11-05 | 2011-02-17 | Hiroshi Kaneko | Copper alloy sheet material |
| JP4440313B2 (en) * | 2008-03-31 | 2010-03-24 | 日鉱金属株式会社 | Cu-Ni-Si-Co-Cr alloy for electronic materials |
| AU2012298166A1 (en) * | 2011-08-22 | 2013-05-02 | Rivers Carbon Technologies Limited | Shearer pick |
| CN102418003B (en) * | 2011-11-24 | 2013-05-08 | 中铝洛阳铜业有限公司 | Processing method of nickel-chromium-silicon-bronze alloy |
| CN103484700A (en) * | 2013-09-13 | 2014-01-01 | 昆山市巴城镇顺拓工程机械配件厂 | Special alloy preparation technology |
| CN105925838B (en) * | 2013-11-29 | 2017-11-07 | 国网河南省电力公司平顶山供电公司 | A kind of production technology of alloy |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1658186A (en) * | 1925-02-21 | 1928-02-07 | Electro Metallurg Co | Copper alloy and process of producing and treating the same |
| US1778668A (en) * | 1927-06-30 | 1930-10-14 | Gen Electric | Electrode |
| US1763303A (en) * | 1928-11-14 | 1930-06-10 | Ohio Brass Co | Trolley wheel |
| US2241815A (en) * | 1938-08-12 | 1941-05-13 | Mallory & Co Inc P R | Method of treating copper alloy castings |
| DE1107943B (en) * | 1955-08-08 | 1961-05-31 | Ver Deutsche Metallwerke Ag | Age-hardening copper alloys |
| DE1278110C2 (en) * | 1960-03-09 | 1973-09-20 | Ver Deutsche Metallwerke Ag | USE OF A CURABLE COPPER ALLOY FOR THE MANUFACTURE OF SEMI-FINISHED PRODUCTS WITH INCREASED MOLDING CAPACITY |
| US3072508A (en) * | 1961-02-15 | 1963-01-08 | Ampco Metal Inc | Method of heat treating copper base alloy |
| GB1358055A (en) * | 1971-09-22 | 1974-06-26 | Langley Alloys Ltd | Copper-based alloys |
-
1979
- 1979-02-12 US US06/011,110 patent/US4191601A/en not_active Expired - Lifetime
- 1979-09-07 AU AU50661/79A patent/AU530377B2/en not_active Ceased
- 1979-09-24 FI FI792962A patent/FI69875C/en not_active IP Right Cessation
- 1979-09-26 AT AT0632579A patent/AT370445B/en not_active IP Right Cessation
- 1979-09-27 BE BE197347A patent/BE879035A/en unknown
- 1979-09-30 NL NL7907272A patent/NL7907272A/en active Search and Examination
- 1979-10-03 JP JP54127841A patent/JPS5937340B2/en not_active Expired
- 1979-10-11 CH CH9174/79A patent/CH648598A5/en not_active IP Right Cessation
- 1979-10-15 ES ES485022A patent/ES485022A1/en not_active Expired
- 1979-10-15 IT IT50560/79A patent/IT1164838B/en active
- 1979-10-18 GB GB7936140A patent/GB2043690B/en not_active Expired
- 1979-10-19 DE DE19792942345 patent/DE2942345A1/en active Granted
- 1979-10-26 SE SE7908899A patent/SE440669B/en not_active IP Right Cessation
- 1979-11-06 CA CA339,297A patent/CA1126056A/en not_active Expired
- 1979-11-30 FR FR7929547A patent/FR2448578A1/en active Granted
-
1980
- 1980-01-12 KR KR1019800000108A patent/KR880000766B1/en active
-
1986
- 1986-02-05 KR KR1019860000803A patent/KR880001524B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| KR830002054A (en) | 1983-05-21 |
| CH648598A5 (en) | 1985-03-29 |
| DE2942345A1 (en) | 1980-08-21 |
| AU5066179A (en) | 1980-08-21 |
| FR2448578A1 (en) | 1980-09-05 |
| DE2942345C2 (en) | 1993-08-19 |
| KR880000766B1 (en) | 1988-05-06 |
| GB2043690B (en) | 1983-08-03 |
| IT7950560A0 (en) | 1979-10-15 |
| SE440669B (en) | 1985-08-12 |
| SE7908899L (en) | 1980-08-13 |
| NL7907272A (en) | 1980-08-14 |
| AT370445B (en) | 1983-03-25 |
| BE879035A (en) | 1980-01-16 |
| AU530377B2 (en) | 1983-07-14 |
| US4191601A (en) | 1980-03-04 |
| GB2043690A (en) | 1980-10-08 |
| JPS5937340B2 (en) | 1984-09-08 |
| FI69875C (en) | 1986-05-26 |
| FR2448578B1 (en) | 1985-05-24 |
| FI69875B (en) | 1985-12-31 |
| IT1164838B (en) | 1987-04-15 |
| KR880001524B1 (en) | 1988-08-19 |
| ATA632579A (en) | 1982-08-15 |
| KR880000604A (en) | 1988-03-28 |
| JPS55107745A (en) | 1980-08-19 |
| ES485022A1 (en) | 1980-04-16 |
| FI792962A (en) | 1980-08-13 |
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