DE2704765A1 - COPPER ALLOY, METHOD OF MANUFACTURING IT AND ITS USE FOR ELECTRIC CONTACT SPRINGS - Google Patents

Description

u.z. : M 015 (Vo / Ra / H)

Case: USSN 655 791-B

OLIN CORPORATION

New Haven, Connecticut, V.St.A.

"Copper alloy, process for their production and their use for electrical contact springs"

Copper alloys should have good strength properties and a favorable ratio of strength to ductility. They should be able to be machined hot and cold at low manufacturing costs and have high mechanical strength, have a favorable combination of strength and ductility and excellent deformation properties. Copper alloys with the above properties should also be easy to process and economical in technical terms Have a scale made.

There is a need for copper alloys of the above type which meet the high demands made in use can be used as electrical contact springs, with high strength combined with good flexural properties

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as well as resistance to deterioration of the mechanical properties at moderately high temperatures, for example, resistance to stress relaxation.

The engineered copper alloys usually have one or more of the above properties not enough. For example, the copper alloy 510 (a phosphor bronze with 3.5 to 5.8% tin and 0.03 to 0.35% phosphorus) good strength, but only unsatisfactory Bending behavior. The copper alloy 725 (a copper-nickel alloy with 8.5 to 10.5% nickel and 1.8 to 2.8% tin) is on the other hand, with regard to the bending behavior, the solderability and the contact resistance are satisfactory, however, it has only low strength.

Copper alloys containing nickel and aluminum are disclosed, for example, in US Pat. Nos. 2,101,087, 2,101,626 and 3 399 05? known. However, these patents do not concern

Nodal, fill-hardened copper alloys with a fine distributed precipitation of Ni-Al particles.

The invention is based on the object of providing a copper alloy with excellent strength and a favorable ratio

nis from strength to ductility to create that as well

x or Ausscheidunqsqehärteten / excellent formability in the precipitation hardened ^v state and

Resistance to deterioration in mechanical properties at moderately elevated temperatures, for example L · _J

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^ against stress relaxation, and especially for use is suitable for electrical contact springs. In addition, the copper alloy should work comfortably and in technical Have the scale manufactured economically. This object is achieved by the invention.

The invention thus relates to that characterized in the claims Object.

The copper alloy according to the invention preferably contains 10 to 20% nickel and 1.5 to 3.5% aluminum (all percentages refer to weight).

The alloy according to the invention can also contain further alloy constituents in order to achieve particular combinations of properties contain. Up to a total of 20% titanium, zirconium, hafnium, beryllium, vanadium, niobium, Tantalum, chromium, molybdenum, tungsten, zinc, iron, tin or mixtures thereof may be included. Zinc, iron and tin can be jewells used in amounts of 0.01 to 10% for additional solution strengthening, machining hardening and precipitation hardening as they are evenly or preferably on the nickel-aluminum rich precipitation and the matrix of oil-copper to distribute. As a result, they harden the matrix and the precipitation, since they influence the lattice parameters of the matrix and the precipitation. This increases the interfacial tension and the precipitation hardening increases. A content of iron in the solution also reduces the grain size.

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Titanium, zirconium, hafnium and beryllium can each be used in an amount of 0.01 to 5%. These metals cause a second precipitation in the alloy matrix as they form intermediate phases with copper and / or nickel. Vanadium, Niobium, tantalum, chromium, molybdenum and tungsten can also each be used in an amount of 0.01 to 5%. The use of these metals is beneficial because they cause a second precipitation in the alloy matrix in elemental form form. As a result, titanium, zirconium, hafnium, beryllium, Vanadium, niobium, tantalum, chromium, molybdenum, tungsten or mixtures thereof in the alloy according to the invention for a additional precipitation hardening, the alloy matrix containing particles of a second precipitation from these metals, or used to achieve improved machining properties, for example to control the grain size. Even a small amount of any of the above metals can also affect the reaction kinetics and morphology influence in the formation of the Ni, Al precipitation.

In addition to the components described above, the alloy according to the invention can contain up to a total amount of 5% lead, arsenic, antimony, boron, phosphorus, manganese, silicon, a lanthanide metal such as mischmetal or cerium, magnesium or lithium, each in an amount of 0.001 to 3 % or mixtures thereof. These alloy additives improve the mechanical properties or the corrosion resistance or the machining properties of the alloy. The molten alloy can be processed with the

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oxidation or desulfurization of additives used in copper be deoxidized. Specific examples of such additives are manganese, lithium, silicon, boron, magnesium or Mischmetal. Those described above as alloy components or precipitants or dispersed additives can also be used Elements are used in small quantities to deoxidize the melt, e.g. titanium, zirconium, Hafnium, chromium, molybdenum and excess aluminum.

Additions of arsenic and antimony can be used to improve corrosion resistance. Also surrendered Additions of compounds containing lead, sulfur and / or tellurium an easily machinable alloy, if the one in question

Alloy is not easily rollable without such an addition. 15th

The nickel and aluminum content in the alloy according to the invention causes the precipitation hardening mechanism due to the spinodal precipitation of the Ni ₃ -Al phase from the solution-annealed and cooled or the solution-annealed, cooled and cold-worked matrix. The morphology of the precipitation is controlled by a suitable selection of the processing and / or alloying conditions. The ratio of strength to ductility of the alloy according to the invention is indirectly controlled via the morphology of the finely divided precipitate.

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^Γ - ιι - 270Α765 ^π

The most important characteristic of the alloy according to the invention its content is a finely divided precipitate of Hi, Al particles, which are dispersed throughout the alloy matrix. The alloys can vary according to the type of machining contain three different morphological manifestations of the Hi-Al precipitation, their selection from the mechanical ones sought Properties and / or processing properties depends. The first morphological manifestation, type (1), is characterized by a finely distributed Ni, Al precipitation, which form agglomerated large grain boundary particles or scattered spheroidal particles and according to the mechanism the classical nucleation and the growth of particles of the second phase at grain boundaries or at voids in the lattice develop. The second manifestation, type (2), the fine distributed Ni, Al precipitation can be achieved by precipitation from the cc-copper according to the mechanism of discontinuous precipitation develop. The third manifestation, type (3), the finely divided Ni, Al precipitation can be extreme in the form of agitation finely distributed, coherent particles arise.

The finely divided precipitations of Ni, Al particles described above, which are dispersed throughout the alloy matrix are caused by the spinodal decomposition of the supersaturated solid solution, followed by coarsening of the grain and converting the solute rich regions into Ni, Al preprecipitation and equilibrium precipitation particles. These Particles are formed according to the mechanism of a spinodal decomposition, which is responsible for the extraordinary properties of the

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alloy according to the invention, for example the unusual combination of strength and ductility, is responsible. This is particularly surprising given that other spinodal alloys are unusually good in the quenched and tempered condition Not possessing strength and flexural ductility. These properties occur, for example, in the copper-nickel-tin alloy system not on.

The alloy according to the invention can be cast by any known method, such as direct hard or continuous casting. The alloy is homogenized for at least 15 minutes at a temperature of 600 ⁰ C until its solidus temperature and then hot rolled at a finishing temperature of about 400 ⁰ C. A typical alloy according to the invention with a content of 15% nickel and 2% aluminum has, for example, a solidus temperature of 1120 ^° C. Homogenization can be combined with hot rolling, that is, the alloy can be heated to the initial temperature required for hot rolling and for homogenization required time to be kept at this temperature. The starting temperature for hot rolling is preferably in the range of the solid solution of the alloy in question.

After hot rolling, the alloy can be cold-rolled ^{at a temperature below 200 °} C. with or without intermediate annealing, depending on the particular requirements with regard to its thickness. The glow can generally in

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Strip or batch operation for 10 seconds to 24 hours Temperatures from 25O ° C to 50 ° C below the solidus temperature of the alloy in question.

The alloy is then solution-annealed at a temperature of 650 to 1100 ^° C., generally above 800 ^{° C.} This solution annealing is of the greatest importance in the process according to the invention, since it is required for the formation of the extremely finely distributed Νΐ, ΑΙ particles through the spinodal decomposition during cooling. The solution heat treatment lasts from 10 seconds to 24 hours.

After the solution treatment, the alloy is brought to room temperature cooled down. It has been found that a change in the machining parameters can lead to significantly different combinations of properties in the alloy obtained. In particular

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of which it was found that the cooling rate of the temperature of the solution heat treatment for the morphology of the cases treatment in the subsequent quenching and tempering treatment of the solution annealed or solution annealed and cold rolled alloy is important. When the alloy after solution heat treatment is quenched in water, i.e. for example at an average speed of 650 ° C / min or faster is cooled, then one observes the precipitation of the discontinuous type (2) and possibly in the quenched and tempered alloy also of the agglomerated type (1). An alloy which is quenched after solution heat treatment in water and thereafter cold-rolled and tempered, contains a mixture of all three types of Ni, Al precipitation. Will the alloy oppose it slowly cooled after solution treatment, i.e. for example with an average speed of 80 ° C / min or less, then one observes the Ni, Al precipitation of the type (3) » which is formed as a network of connected, extremely finely distributed particles "C. This type of precipitation is used in the only solution-annealed alloy as well as solution-annealed and quenched and tempered or solution-annealed, cold-rolled and tempered alloy observed. In another embodiment, the solution annealed alloy also only cooled down to the tempering temperature, then tempered at this temperature and then cooled to room temperature will. In this case too, the type (3) precipitation is obtained.

ORIGINAL INSPECTEb

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After the solution heat treatment, the alloy can be slowly cooled or quenched. In addition, the solution annealed Alloy can be tempered for 30 minutes to 24 hours at a temperature of 250 to 65O ° C. The final state of the Alloy can either be solution annealed, solution annealed and quenched and tempered or solution annealed, cold rolled and quenched and tempered.

In a further embodiment of the invention, further cold rolling can be provided after the tempering treatment. This additional cold rolling provides additional strength, but decreases formability and ductility.

For applications that require a high degree of ductility, the alloy according to the invention is used after the solution heat treatment deterred. Subsequent cold rolling and quenching and tempering result in both higher strength and better ductility than exclusive Cold rolling. The improvement in both properties through the tempering treatment is particularly noteworthy .

If the highest level of strength, rather than ductility, is desired, the alloy is cooled slowly after the solution heat treatment. The post-processing in this state, i.e. Cold rolling and quenching and tempering improves strength with only a slight decrease in formability. It is surprising that an alloy that has cooled down slowly after the solution treatment reacts to a quenching and tempering treatment in this way.

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The alloys according to the invention can thus obtain a number of different properties through different processing, which are associated with the control of the cooling rate after the solution heat treatment at a temperature of 650 to 1100.degree. The hardening and tempering treatment at temperatures of 250 to 650 ^° C. and a duration of 30 minutes to 24 hours leads to an improved combination of properties. The alloys can optionally be cold-rolled between solution annealing and quenching and tempering, for example up to a degree of deformation of 9.0%, the individual conditions and the extent of rolling depending on the desired end properties. The process for producing the alloys according to the invention is therefore surprisingly versatile and allows a large number of changes in order to obtain a wide range of different combinations of properties.

The preferred processing measure of the method according to the invention is rolling. However, other types of processing, such as extrusion, forging or drawing into wires, can also be used. be used.

Molded parts can be made from the cold-rolled and / or tempered alloy and, if necessary, heat-treated after molding. The heat treatment may be made in the above-described annealing, or at least 15 minutes at low temperatures such as are I50, carried out to 300 ⁰ C to improve the resistance to stress and corrosion.

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The examples illustrate the invention.

Example 1 tensile properties

A copper alloy with a content of 15 percent by weight nickel and 2 percent by weight aluminum is ^{poured at a temperature of 1350 °} C. into a steel mold with a water-cooled base plate made of copper. After that, 4.54 kg heavy feedstock is annealed 4- hours at 1000 C, followed immediately with a final temperature of about 500 ⁰ C of 44.5 mm to 10.2 mm hot-rolled and then cold rolled to 3.0 mm. Then the alloy is solution heat treated for 1 hour at 850 ⁰ C and then quenched in water to room temperature. After that, samples of the alloy are further processed to a thickness of 0.5, now in the quenched and cold-rolled condition to a degree of deformation of 20, 40, 60 and 83%. Part of the alloy is cold-rolled directly to 0.5 mm, ie with a degree of deformation of 83%. Another portion of the alloy is first cold rolled to 1.3 mm, then solution heat treated for 1 hour at 850 ⁰ C and then 0.5 mm cold-rolled to, that is, with a degree of deformation of 60%. Another part of the alloy is first cold rolled to 0.8 mm, then solution heat treated for 1 hour at a temperature of 850 ⁰ C and then 0.5 mm, that is, with a degree of deformation of 40%, cold-rolled.

Another part of the alloy is cold-rolled to 0.6 mm, then solution-annealed for 1 hour at a temperature of 85O ° C and then cold-rolled to 0.5 mm, i.e. with a degree of deformation of 20%. Part of the with a degree of deformation

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of 60% cold-rolled alloy is used to produce final solution-alloy ie "solution treated with a cold deformation of 0%, 1 hour at a temperature of 850 ⁰ C. The alloys are quenched after each solution annealing in water at room temperature. From the to 0, 5 mm cold-rolled alloys each part is ^{tempered for 24 hours at a temperature of 400 °} C. The tensile properties of the exclusively cold-rolled and the additionally tempered alloys are then measured.

These are summarized in Table I. For comparison are also the values of the technical high-strength copper alloys CDA 510 (4.4% tin, 0.07% phosphorus, remainder copper) and CDA 638 (2.7% Aluminum, 1.7% silicon, 0.4% cobalt, remainder copper). The values in Table I show the remarkable strength and the good strength-to-ductility ratio of the tempered alloys according to the invention. Investigating the The microstructure of the tempered alloys shows that they have a finely distributed precipitation of Ni-Al particles in the entire alloy matrix contain.

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Table I.

alloy Cold Tensile stress, Tensile strength Strain, shaping the one lead ability, % Degree, % end of demand kg / cm ² ming of 0.2% causes kg / cm ² Cu-15Ni-2Al 0 1547 4218 32.8 Cu-15Ni-2Al 0+ remunerated 5343 7944 17.2 CDA 510 0 2812 3937 46.0 CDA 638 0 3585 5624 35.0 Cu-15Ni-2Al 20th 4148 4640 13.3 Cu-15Ni-2Al 20+ remunerated 5694 8085 17.7 CDA 510 20th 4570 5062 20.0 CDA 638 20th 5765 7452 10.0 Cu-15Ni-2Al 40 5483 5694 1.0 Cu-15Ni-2Al 40+ remunerated 6397 8436 16.8 CDA 510 40 6538. 6819 5.0 CDA 638 40 6960 8436 5.0 Cu-15Ni-2Al 60 5905 6046 1.3 Cu-15Ni-2Al 60+ remunerated 7382 8788 15.0 CDA 510 60 7522 7733 2.0 CDA 638 60 7733 9139 3.0 Cu-15Ni-2Al 83 6327 6468 1.0 Cu-15Ni-2Al 83+ remunerated 8295 9912 14.0 CDA 510 83 8014 8436 1.0 CDA 638 83 8295 9772 1.0

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Example2 Tensile properties

A copper alloy with a content of 15 percent by weight Nickel and 2 percent by weight aluminum are cast and machined according to Example 1, but with the change that the Alloy is cooled to room temperature after each solution heat treatment in air. It will be the train properties again the exclusively cold-rolled and the additionally hardened and tempered alloys were measured. The results are in Table II summarized. The microstructures of the solution-annealed, the solution-annealed and cold-rolled as well as the solution-annealed, cold-rolled and tempered alloys are examined. It was found that it was finely divided Precipitations of Ni, Al particles contained in the whole alloy matrix. Compared to those listed in Table I. Properties of the two technical, high-strength alloys 510 and 638 are clearly shown by the values in Table II Improvement of the strength of both the exclusively rolled and the additionally tempered alloys according to the invention. It is particularly surprising that slowly cooled, heat treatable alloys without fracture to such an extent can be cold rolled.

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- 2Λ - Table II

editing Tensile stress, the
a permanent one
Deformation of
Causes 0.2%,
kg / cm2 Tensile strength
ability,
kg / cm2 Deh
tion solution annealed 3234 6186 28.0 solution annealed + tempered 3656 6468 19.7 20% cold rolled 8998 9350 4.8 20% cold rolled + tempered 9280 9631 2.9 40% cold rolled 9280 9983 1.0 40% cold rolled + tempered IOI23 10826 2.1 60% cold rolled 9209 9983 2.0 60% cold rolled + tempered 10404 11107 2.1 83% cold rolled 8788 9772 3.5 83% cold rolled + tempered 10615 11951 3.0

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Example 3 Bending behavior

The flexural behavior of the samples 1 and 2 is processed Investigated copper alloy with a content of 15% nickel and 2% aluminum. In detail, the 90 ° flexural strength of the hardened and tempered alloys. The bending strength is determined by the smallest radius around which a Strip can be bent without breaking. The bending test is performed one perpendicular to the rolling direction and one parallel to the rolling direction running axis executed. The longitudinal strength refers to the axis perpendicular to the rolling direction and the transverse strength to the axis parallel to the rolling direction. The smallest bending radius at which a break does not yet occur and the thickness of the strip are determined, which in in this case is always 0.5 mm. The results are summarized in Tables ΙΙΙΑ, ΙΙΙΒ, HIC and HID. In table IHA are the results of the bending test of the water-quenched and Table IHB shows the results of the copper alloy according to the invention cooled in air. In In Table IHC, the values for the smallest bending radius are divided by the thickness of the strip of the known alloys 510 and 638 with the corresponding values of an inventive Alloy compared. Given the strength, the quenched and tempered alloy of the present invention exhibits greater bending formability both perpendicular and parallel to the rolling direction, i.e. lower values for the smallest Bend radius divided by the thickness of the strip, as alloys 510 and 633. Table HID shows that, the

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alloys according to the invention compared to the alloys 510 and 638 for a given value for the smallest bend radius divided by the thickness of the strip, a higher one Need tensile stress to cause a permanent deformation of 0.2%. A higher strength for a given bending radius is desirable in engineering. The hardened and tempered alloys according to Examples 1 and 2 have, in comparison to the high-strength engineered alloys 510 and 638, a greater strength for a given bending radius, especially in the critical direction parallel to the rolling direction. Particularly It is important that the alloys according to the invention have sufficient flexural ductility for a given strength that cannot be achieved by other alloys.

Table IHA

Machining * tensile stress, smallest bending radius /

the one after the thick one

Reward one

remaining perpendicularly parallel

forming 0.2%, kg / cm ²

Deterred + tempered 5343 pointed pointed

20% cold rolled + tempered. 5694 0.4 1.6

40% "" "6397 0.4 0.4

60% "" "7382 0.8 1.6

83% "" "8295 7.8 9.4

* Remuneration takes place 24 hours at 400 ^° C. and a thickness of 0.5

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Table HIB

Machining * tensile stress, smallest bending

which after the dius / thickness tempering a

permanent vertical parallel deformation of 0.2%, kg / cm ²

Deterred + rewarded 3656

20% cold rolled + tempered. 9280

40% "" "10123

10 60% "" "10404

83% "" "10615

* Compensation takes place 24 hours at 400 ^° C. and a thickness of 0.5 mm

pointed pointed 6.2 5.5 6.2 5.5 6.2 7.8 7.8 12.5

Tabel IHC 2 parallel CDA 510 CDA 638 , 8 2.1 Tensile stress,
the one 4th 0.2 vertical . parallel vertical par. , 5 3.3 permanent
deformation
from 0.2% 2
precalls, kg / cm Smallest bending radius / thickness 7th 0.4 0.2 1.6 O , 2 4.3 5624 Cu ~ 15Ni-2Al 4th 1.1 0.4 3.2 1 , 2 10.0 6327 vertical 4th 2.0 1.0 4.3 2 , 8> 25 7O3O 0, 2 . 3.2 1.8 9.0 3 - 7733 0, 7th 5.0 - - 4th 8436 0, 7.0 - - - 9139 1, _ _ 9842 2, 4, 5,

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- 25 - 2704765 7IOO cold rolled
CDA 638 Table HID 7803 5976 Perpendicular
Smallest
Biegera
dius / thickness Tensile stress, which is a permanent deformation of
0.2%, kg / cm - 6819 1 quenched and tempered cold rolled
CU-151H.-2A1 CDA 510 - 7522 2 7382 - 8225 3 8155 - 8936 * 86 * 7 - 5 9069 53 * 3 6th 9 * 91 5905 * 921 parallel
smallest
Biegera
dius / thickness 9983 6327 555 * 1 6679 6257 2 6889 6960 6679 3 7733 7171 6960 * 8295 7171 5 8788 6th 9209 9631

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Example* High strength and bending behavior

The surprising advantage of the alloy according to the invention is that in the quenched and tempered state it has an excellent strength-to-ductility ratio with high strength. This property is not observed in technical, yellowing-hardened copper alloys with high strength, such as beryllium copper alloys and an alloy with a nominal content of 9% bead1 and 6% tin. In order to utilize their potentially high strength, these known alloys are also solution annealed, cold-rolled and tempered. A molded part which has to be produced by pressing or bending, as is necessary in the case of a typical electrical contact spring, must, however, be deformed in the cold-rolled state and tempered only after the deformation. In practice, this means that the molded part must be supported in a corresponding manner with the aid of expensive holding devices in order to avoid undesired deformations occurring during the hardening process. Another way is to cold-roll the solution-annealed alloy and only partially heat-treat the strip so that sufficient flexural formability and strength is achieved without the heat-treatment after deformation. In this process, however, the possible strength of these expensive alloys is only partially exploited. The alloy according to the invention, on the other hand, has the advantage that the corresponding bending behavior is also achieved if it is tempered to high strength after solution annealing and cold rolling. This will

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1 the full recovery of the high strength at the same time with corresponding bending behavior possible. In Table IV are the elongation and bending values for the alloy of the invention as well as for comparison for a beryllium copper and a

5 copper-hickel-tin alloy combined.

Table IV

Alloy and editing

Tensile stress ₇ tensile strain smallest bending

the one strengthening, radius / thickness

permanent keiti 2% lower- parallel-

Ver shaping kg / cm

of 0.2%

causes

kg / cm ^

Law

lel

Cu-15Ni-2Al

40% cold rolled 9280

tempered 400 ⁰ C,

24 hours 10123

Cu-11.9Ni-4.8Sn cold rolled 78? 4

remunerated 9420

CDA 172 (Cu-1,9Be-O, 2Co) cold-rolled, partly tempered 7522

9983 1.0 3.9 5.0

10826 2.1 6.2 5.0

8577 2.7 2.8 2.8

9983 5.0 11.1> 11.1

9491 14.8 1.2

1.5

Example 5

Copper-nickel-aluminum alloys with high strength Combined aluminum contents. The tensile strength will

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measured on solution-annealed, cold-rolled and tempered alloys. The alloys are manufactured and processed according to example 1 and 2. The solution heat treatment is carried out at a temperature of 1000.degree. The study of the microstructure of all alloys shows the content of finely distributed precipitation of Ni, Al particles in the entire alloy matrix. The microstructure of the alloys with a content of Chromium, vanadium and titanium also show the presence of a second precipitate.

Table V

15th alloy Tensile stress,
the one lead
end of demand
ming of 0.2%
causes
kg / cm ² train
firm
ability ^
kg / cm Strain,% Cu-15Ni-2Al-2Cr 10545 11810 1.6 Cu-2ONi-3Al 12373 13568 0.8 Cu-15Ni-2Al-6Fe 11248 12654 2.0 20th Cu-15Ni-2Al-2Cr-0.5Tj ι 12021 12935 0.3 Cu-15Ni-2Al-1V 11670 I3OO6 5.0 Cu-15Ni-3Al 10897 13568 2.7

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Claims (22)

u.z. : M 015 (Vo / Ra / H) Case: USSN 655 791-B OLIN CORPORATION New Haven, Connecticut, V.St.A. 10 "Copper alloy, process for their production and their use for electrical contact springs" Priority: February 6, 1976, V.St.A., No. 655 791 February 6, 1976, V.St.A., No. 655 918 15 20 25 claims 1. Spinodal, precipitation-hardened copper alloy with a Nickel and aluminum content, characterized that they contain 10 to 30% nickel, 1 to 5% aluminum, the balance copper and common impurities and has a finely distributed precipitation of Ni, Al particles in the alloy matrix. 2. Alloy according to claim 1, characterized in that the precipitation from agglomerated large grain boundary particles or scattered spheroidal particles. 709832/074 3 3 · Alloy according to claim 1, characterized in that the Precipitation consists of discontinuous, finely divided particles. 4. Alloy according to claim 1, characterized in that the Precipitation consists of coherent, finely divided particles. 5. Alloy according to claim 1 to 4-, characterized in that it up to a total amount of at most 20% as further alloy component in each case 0.01 to 10% zinc, tin or iron and / or each 0.01 to 5% titanium, zirconium, Contains hafnium, beryllium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten or mixtures thereof. 15th 6. Alloy according to claim 5 »characterized by a content in a second precipitation in the alloy matrix, the titanium, zirconium, hafnium, beryllium, vanadium, niobium, Contains tantalum, chromium, molybdenum, tungsten or a mixture of these. 7. Alloy according to claim 5 and 6, characterized in that that they contain lead, arsenic, antimony, boron, phosphorus, up to a total amount of not more than 5%, Manganese, silicon, a lanthanide metal, magnesium or lithium each in an amount of 0.001 to 3% or their Mixture contains. 709832/0743 8. Alloy according to claim 1 to 4, characterized in that it is solution annealed. 9. Alloy according to claim 8, characterized in that it is solution annealed and tempered. 10. Alloy according to claim 9, characterized in that it is solution annealed, cold-rolled and tempered. 11. A method for producing the alloy according to claim 1, characterized in that an alloy with 10 to 30% nickel and 1 to 5% aluminum, the remainder copper and usual impurities with a final temperature of over 400 ⁰ C is hot-worked for 10 to 24 hours Solution annealed at 650 to 110O ⁰ C and then cooled to room temperature. 12. The method according to claim 11, characterized in that the alloy is homogenized before hot working for at least 15 minutes at a temperature of 600 ⁰ C up to the solidus temperature of the alloy. 13. The method according to claim 11 and 12, characterized in that that the alloy is cold worked after hot working but before solution heat treatment. 14. The method according to claim 13, characterized in that all processing stages consist of rollers. 709832/0743 15 · The method according to claim 14, characterized in that the alloy during the cold working in between 10 seconds to 24 hours at a temperature of Glows between 25 ° C and 50 ° C below the solidus temperature. 16. The method according to claim 11 and 12, characterized in that that the alloy is quenched in water after the solution heat treatment. 17. The method according to claim 16, characterized in that the alloy after quenching for 30 minutes Tempered for 24 hours at a temperature of 250 to 65O ° C. 18. The method according to claim 16 and I7, characterized in that that the alloy is cold-rolled and tempered after quenching. 19. The method according to claim 11 and 12, characterized in that that the alloy is slowly cooled after the solution treatment. 20. The method according to claim 19, characterized in that the alloy is tempered for ^{30 minutes to 24 hours at a temperature of 250 to 650 0 C after slow cooling.} 709832/0743 1 21. The method according to claim 20, characterized in that the alloy is cold-rolled and tempered after slow cooling. 5 22. Use of the alloys according to claim 1 "to 10 for Manufacture of electrical contact springs. 709832/0743