MXPA99003694A - Copper alloy and process for obtaining same - Google Patents

Abstract

A copper base alloy consisting essentially of tin in an amount from about 0.1 to about 1.5%by weight, phosphorous in an amount from about 0.01 to about 0.35%by weight, iron in an amount from about 0.01 to about 0.8%by weight, zinc in an amount from about 1.0 to about 15%by weight, and the balance essentially copper, including phosphide particles uniformly distributed throughout the matrix, is described. The alloy is characterized by an excellent combination of physical properties. The process of forming the copper base alloy described herein includes casting, homogenizing, rolling, process annealing and stress relief annealing.

Description

COPPER ALLOY AND PROCEDURE TO OBTAIN THE SAME CROSS REFERENCE TO RELATED APPLICATIONS This application is related to the US Patent application of. No. 08 / 747,014 filed on November 7, 1996, entitled COPPER ALLOY AND PROCEDURE FOR OBTAINING SAME, and US Patent Application No. 08 / 780,116, filed December 26, 1996, entitled COPPER ALLOY AND PROCEDURE FOR OBTAINING THE SAME.

BACKGROUND OF THE INVENTION The present invention relates to copper-based alloys having utility in electrical applications and to a process for producing such copper-based alloys. There are a number of copper-based alloys that are used in connectors, conductor frames and other electrical applications due to their special properties that are well suited for these applications. Despite the existence of these alloys, remains in the _ne_cesidad. of copper-based alloys that can be used in applications requiring a high yield strength greater than 80 KSI, together with good forming properties that allow bends to be made in poor conditions at 180 ° with an R / T ratio of 1 or less plus a low tension relaxation at high temperatures freedom from cracking by stress corrosion. The alloys currently available do not meet all these requirements or have high costs that make them less economical in the market or have other significant disadvantages. It remains highly desirable to develop a copper-based alloy that satisfies the above objectives. Generally, beryllium-c oi) re has a very high strength and conductivity together with good stress relaxation characteristics; however, these materials are limited in their training ability. One of these limitations' is the difficulty with 180 ° push-ups. In addition, they are very expensive and usually require an extra heat treatment after the preparation of a desired part. Naturally, this adds even more to the cost.

The phosphor-bronze materials are inexpensive alloys with good strength and excellent forming properties. They are widely used in electronics and telecommunication industries. However, they tend to be undesirable since they require very high current driving under very high temperature conditions, for example under conditions found in automotive applications to be used under the cover. This combined with its high thermal stress relaxation regime makes these materials less suitable for many applications. High conductivity alloys with a high copper content also have some desirable properties, but generally have no resistance. desired mechanics for numerous applications. Typical of these alloys include, but are not limited to, copper alloys 110, 122, 192 and 194. Representative patents of the prior art include U.S. Patents 4,666,667 4,627,960 2,062,427 4,605,532 4,586, 4,622,562 and 4,935,076. Accordingly, it is highly desirable to develop copper-based alloys having a combination of desirable properties making them eminently suitable for many applications.

BRIEF DESCRIPTION OF THE INVENTION According to the present invention, it has been found that the above object is "easily obtained." The copper-based alloys according to the present invention consists essentially of tin in an amount of about 0.1 to about 1.5. %, preferably from about 0.4 to 0.9%, phosphorus in an amount from about 0.01 to about 0.35%, preferably from about 0.01% to about 0.1%, iron in an amount from about 0.01% to about 0.8%, of reference from about 0.05 to about 0.25%, zinc in an amount of about 1.0 to about 15%, preferably from about 6.0 to about 12.0%, and the remainder being essentially copper. It is particularly advantageous to include nickel and / or cobalt in an amount of up to about 0.5% each, preferably in an amount of about 0.001% at approx. slightly 0.5% each. The alloys according to the present invention can also include up to 0.1% of each one of aluminum, silver, boron, beryllium, calcium, copper, indium, lithium, magnesium, manganese, lead, silicon, antimony, titanium and zirconium. As used herein, the percentages are percentages by weight. It is desirable and advantageous in the alloys of the present invention to provide iron and / or nickel and / or magnesium rosfur particles or a combination thereof, uniformly distributed throughout the matrix, since these particles serve to increase the strength, Conductivity and stress relief characteristics of the alloys. The phosphide particles can have a particle size of 50 Angstroms to about 0.5 microns and can include a finer component and a thicker component: The finer component can have a particle size ranging from about 50 to 250 Angstroms, preferably from about 50 to ^ 00 Angstroms. The thicker component may have a particle size generally of 0.075 to 0.5 microns, preferably 0.075 to 0.125 microns. The alloys of the present invention enjoy a variety of excellent properties making them eminently suitable for use as connectors, conductor frames, springs and other electrical applications. The alloys must have an excellent and unusual combination of mechanical strength, formability, thermal and electrical conductivities, and relaxation properties by tension. The process of the present invention comprises: casting a copper-based alloy having a composition as mentioned. above; homogenizing at least once for at least one hour at temperatures of about 537.7 to 787.7 ° C; laminate to a finishing gauge including by hand an annealing process for at least one hour at 343.3 to 648.8 ° C; and annealing by stress relief for at least one hour at a temperature in the range of 148.8 to 315.5 C, thereby obtaining a copper alloy including phosphide particles uniformly distributed throughout the matrix. HE may include nickel and / or cobalt alloy as above.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The alloys of the present invention are modified copper-zinc alloys. HE they characterize by higher resistances, better forming properties, higher conductivity and tensile relaxation properties which represent a significant improvement over the same properties of unmodified alloys.

Alloys according to the present invention include those copper-based alloys consisting essentially of tin in an amount of about 0.1 to 1.5%, preferably about 0.4 to 0.9%, phosphorus in an amount of about 0.01 to about 0.35% , preferably from about 0.01 to about 0.1%, iron in an amount of about 0.01 to about 0.8%, preferably about 0.05 about 0.25%, zinc in an amount of about 1.0- to about 15%, preferably around 6.0 to approximately 12%, and the rest being essentially copper. These alloys will typically have uniformly insulated phosphide particles throughout the matrix. _ _ These alloys may also include nickel and / or cobalt in an amount up to approximately 0.5% each, preferably -Over 0.001 ^ approximately 0.5%. of one or combinations of both. One or more of the following elements may be included in the alloy combination: aluminum, silver, boron, beryllium, calcium, chromium, indium, lithium, magnesium, manganese, lead, silicon, antimony, titanium and zirconium. These materials can be included in amounts less than 0.1%, generally each in an excess of 0.001. The use of one or more of these materials improves the mechanical properties such as stress relaxation properties; however, larger amounts can affect conductivity and formation properties. The aforementioned phosphorus addition allows the metal to remain deoxidized making it possible to strain the metal within the established _limit.es for phosphorus, and with the heat treatment of the alloys, the phosphorus forms a phosphide with iron and / or iron and nickel and / or iron and magnesium and / or a combination of these elements, if present, which significantly reduces the conductivity loss that could occur if these materials were completely present. in solid solution in the matrix. It is particularly It is desirable to provide iron particles uniformly or evenly distributed throughout the matrix as this helps to improve the tensile relaxation properties by blocking the dislocation movement. The iron in the scale of about 0.01 about 0.8% and particularly about 0.05 about 0.25% increases the tension of the alloys, promotes a fine grain structure acting as an inhibitor of grain growth and in combination with phosphorus in This scale helps to improve the properties of relaxation by tension without negatively affecting the electrical - and thermal conductivities. Nickel and / or cobalt in an amount of about 0.001 to 0.5% each are desirable additives, since they improve the relaxation properties by stress and strength by refining the grain and through the distribution in the matrix, with a positive effect on the conxlucti vity. The procedure of the. present invention includes casting an alloy having a composition as mentioned above. Any suitable casting technique known in the field such as casting Horizontal continuous can be used to form a strip having a thickness on the scale of approximately 1.27 to 1.90 c. The process includes at least one homogenization of at least one hour and preferably in a period in the range of about 1 to 24 hours, at temperatures in the range of about 537.7 to 787.7 ° C. At least one stage of homogenization may be conducted after a rolling step. After homogenization the strip can be ground once or twice to remove approximately 0.Q50 to 0.254 cm of the material from each side. The material is then laminated to a final gauge, including at least one "annealing process from 353.3 to 648.8 ° C for at least one hour and preferably around 1 to 24 hours, followed by a slow stirring at room temperature. from -6.6 to 93.3 ° C for one hour. The material is then annealed by stress relief to a final gauge at a temperature in the range of 148.8 to 315.5 ° C for at least one hour and preferably over a period on a scale of about 1 to 20 hours. This improves Advantageously the formation capacity and the properties of relaxation by tension. The heat treatments advantageously and very desirably provide the alloys of the present invention with iron and / or nickel, and / or magnesium phosphide particles or a combination thereof evenly distributed throughout the matrix. of phosphide increase the resistance, conductivity and characteristics "of relaxation by tension of the alloys. The phosphide particles can have a particle size of about 50 Angstroms a. approximately 0.5 microns and may include a thinner component and a thicker component. The finest composition can have a particle size of about 50 to 250 Angstroms, preferably about 50 to 200 Angstroms. The thickest component may have a particle size generally of 0.75 to 0.5 microns, preferably 0.075 to 0.125 microns. The alloys formed according to the process of the present invention and having the aforementioned compositions are capable of obtaining an elastic limit on the scale of 80-100 ksi i with the capacity of bending at a radius equal to its thickness, under bad conditions, in "a width of up to 10 times the thickness." In addition, they are capable of obtaining an electrical conductivity in the order of 35% IACS, or better.The foregoing coupled with the desired metallurgical structure should give the alloys a high tensile holding capacity, for example about 60% at 150 ° C, then ~ 1000 hours with a tension equal to 75% of its elastic limit in samples cut parallel to the rolling direction, and makes these alloys, Suitable for a wide variety of applications that require high-tension capacities for retention In addition, the alloys herein do not require additional treatment by stampers.

Claims (20)

1. A copper-based alloy consisting essentially of tin in an amount of about 0.1 to about 1.5 wt%, phosphorus in an amount of about 0.01 to about 0.35 wt%, iron in an amount of about 0.01 to approve 0.8% by weight, zinc in an amount of about 1.0 to about 15% by weight and the weight being essentially copper, said alloy including phosphide particles uniformly distributed throughout the matrix, said particles of. Phosphide having a thicker component made of phosphide particles having a size on the scale of 5 to 250 Angstroms and "a thicker component made of phosphide particles having a size on the scale of 0.075 to 0.5 microns.

2. The copper-based alloy, according to the rei indication 1, wherein the zinc content is from about 0.4 to approximately u. 9 - by weight.

3. The copper-based alloy according to claim 1, wherein it includes a material selected from the group consisting of nickel, cobalt and mixture thereof in an amount of about 0.001 to 0.5% by weight of each.

4. The copper-based alloy according to claim 3, wherein the alloy further includes magnesium in an amount of up to 0.1% by weight and the phosphide particles are selected from the group consisting of phosphide particles of iron. nor nickel, iron-magnesium phosphide particles, iron phosphide particles, magnesium-nickel phosphide particles, magnesium phosphide particles and mixtures thereof.

5. The copper-based alloy according to the rei indication 1, wherein the zinc is present in an amount of about 6.0 to 12.0% by weight.

6. The copper-based alloy according to claim 1 further includes lead in an amount of up to about 0.1% by weight. ""

7. The copper-based alloy according to claim 1 further includes at least one addition selected from the group consisting of aluminum, silver, boron, beryllium, calcium, chromium, indium, lithium, magnesium, manganese, lead, silicon. , antimony, titanium and zirconium, at least one addition being present in an amount of up to 0.1% each.

8. The copper-based alloy according to the rei indication 1, wherein the phosphorus content is from 0.1 to approximately 0.10% by weight.

9. The copper-based alloy according to claim 1, wherein the iron content is from about 0.05 to about 0.25% by weight.

10. The copper-based alloy according to claim 1, wherein the thinner component is made up of particles in the forum having a size on the scale of 50 to 200 Angstroms and the thickest component is made up of particles of Phosphide having a size on the scale of 0.075"to 0.125 microns.

11. A process for preparing a copper-based alloy comprising: casting a copper-based alloy consisting essentially of tin in an amount of from about 0.1 to about 1.5% by weight, phosphorus in an amount of from about 0.01 to about 0.35% in weight, iron in an amount of about 0.01 to about 0.8% by weight, zinc in an amount of about 1.0 to about 15% by weight, and the remainder being essentially copper; homogenize at least once for at least one hour at a temperature of 537.7 to 787".7 ° C; laminate to a fi ature gauge1 including at least one annealing procedure for at least one hour from 343.4 to 648.8 ° C followed by slow cooling, and annealing by stress relief to a final gauge for at least one hour from 148.8 to 315.5 ° C, thereby obtaining a copper-based alloy including phosphide particles uniformly distributed throughout the matrix.

12. The process according to claim 11, wherein the copper-based alloy that is cast includes a material selected from the group consisting of nickel, cobalt and mixtures thereof in an amount of about 0.001 to about 0.05% each.

13. The process according to claim 12, wherein the copper-based alloy being cast includes magnesium and the phosphide particles are selected from the group consisting of iron-nickel phosphide particles, phosphide particles of f. rro-agnes io, iron phosphide particles, magnesium phosphide particles -not that 1, magnesium phosphide particles and mixtures thereof.

14. The process according to claim 13, wherein the phosphide particles have a particle size of 50. Angstroms at 0.5 microns.

15. The process according to claim 11, which includes two stages of homogenization, wherein at least one step of The homogenization is subsequent to a rolling stage where the stages of. homogenization are from 2 to 24 hours each.

16. The process according to claim 11, wherein the annealing process is from 1 to 24 hours.

17. The process according to claim 11, wherein the annealing by stress relief is from 1 to 20 hours.

18. The profiling according to claim 11, wherein the casting step forms a strip having a thickness of 1.27 to 1.90 centimeters and the method further includes grinding the strip at least once following at least one homogenization step.

19. The method according to claim 11, wherein the cooling step is performed at a cooling rate of -6.6 to 93.3 ° C per hour.

20. The process according to claim 11, wherein the casting step comprises casting a copper-based alloy consisting essentially of tin in an amount of about 0.4 to about 0.3% by weight, zinc in an amount of approximately 6.0. at about 12.0% by weight, phosphorus "in an amount of about 0.01 to about 0.21 by weight, iron in an amount of about 0.01 to about 0.8% by weight, a material selected from the group consisting of nickel, cobalt and mixtures of the same in an amount of about 0.001 about i1.5 in pe each, and the remainder being essentially copper.