High-strength copper alloy wire and preparation method thereof

Abstract

The invention discloses a high-strength copper alloy wire and a preparation method thereof. The high-strength copper alloy wire is prepared from the following components in percentage by weight: 17-18% of Ni, 3-4% of Sn, 3-4% of Al, 0.5-1% of Co, 0.05-0.1% of P and the balance of Cu and inevitable impurities. The preparation method comprises the following steps: induction melting; extruding a water seal; rolling is conducted; recrystallizing and annealing; continuous drawing is conducted; annealing treatment; continuous drawing is conducted; and annealing treatment. According to the method, the mass fraction of Sn is controlled within 4%, a red copper material is adopted as a casting mold, rapid cooling of a cast ingot is achieved, and the proportion of a brittle Sn-rich area in a matrix is greatly reduced; a water seal extrusion technology is combined to ensure that the element Sn is distributed in a matrix in a solid solution form, so that the cold and hot working properties of the alloy are improved; ni, Co and Al elements are utilized to form a (Ni, Co) 3Al high-temperature-resistant strengthening phase in the annealing treatment process, and the mechanical property of the alloy is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of copper alloy materials, and particularly relates to a high-strength copper alloy wire and a preparation method thereof. Background Art

[0002] Ultra-high-strength beryllium copper alloy materials are widely used in equipment manufacturing, electric power industry, metallurgical industry and other fields. They are the core basic materials for structural functional devices such as mechanical equipment, coaxial cables, and wear-resistant accessories. They combine structural and functional characteristics. However, due to the release of harmful gases during high-temperature treatment, they have been gradually replaced in recent years. Among them, CuNiSn alloy has great potential as a substitute for beryllium copper.

[0003] Currently, the main publicly disclosed preparation methods for CuNiSn alloys are powder metallurgy and melting and casting. Among them, the powder metallurgy method has a higher preparation cost and is suitable for precision parts; the melting and casting method has a simple preparation process, but the problem of alloy element segregation needs to be solved.

[0004] For example, the Chinese invention patent application with application number 202410374926.0 and publication number CN118064761A discloses a copper-nickel-tin wear-resistant and corrosion-resistant copper alloy and its preparation method, whose components (mass percentage) are Ni: 8.7-10.0%, Sn: 2.0-6.5%, Fe≤0.6%, Mn≤0.2%; Zn≤0.5%, Mg≤0.05%, P≤0.05%, Si≤0.15%, and the balance is Cu. Its preparation process includes: smelting, horizontal continuous casting, annealing, rolling, continuous annealing, rolling, and annealing. The copper alloy material provided in this application has a tensile strength of 687-736MPa, a yield strength of 574-680MPa, and an elongation of 15.5-17.5%.

[0005] For example, the Chinese invention patent with application number 202111024970.1 and authorization announcement number CN113789459B discloses a copper-nickel-tin alloy and its preparation method and application, whose components (mass percentage) are Ni: 8-16%, Sn: 5-9%, X1 element 0.1-1.0%, X2 element 0.1-0.5%, wherein X1 is selected from at least one of Ti, Si, Al, and V, X2 is selected from at least one of Mn, Zn, and Mo, and the remainder is Cu and unavoidable impurities. Its preparation process includes: smelting, electromagnetic stirring, semi-continuous casting, homogenization, hot working, solution, cold working, and aging. The copper alloy material provided by the invention has a tensile strength of ≥1100MPa, a yield strength of ≥1050MPa, and an elongation of ≥5%.

[0006] For example, the Chinese invention patent with application number 201610280996.5 and authorization announcement number CN105714148B discloses a high-strength copper-nickel-tin alloy of amplitude modulation decomposition type, whose components (mass percentage) are Ni: 14.0-16.0%, Sn: 7.0-9.0%, Si: 0.1-0.3%, Ti: 0.02-0.10%, and the balance is Cu and unavoidable impurities. Its preparation process includes: atmosphere melting, hot extrusion, solid solution, and annealing. The copper alloy material provided by the invention has a tensile strength of ≥1035MPa and an elongation after fracture of ≥17%.

[0007] For example, the Chinese invention patent with application number 202111564151.6 and authorization announcement number CN114196851B discloses a high-strength conductive copper alloy material and its preparation method, whose components (mass percentage) are Ni: 5-16%, Sn: 5-10%, Mg: 0.05-0.5%, trace elements 0.002-0.16% and the balance Cu. Its preparation process includes: smelting, hot extrusion, solid solution, aging, cold deformation, and annealing. The copper alloy material provided by the invention has a tensile strength of ≥1000MPa, a yield strength of ≥950MPa, and an elongation after fracture of ≥1%.

[0008] The problem of element segregation in CuNiSn alloy is the main factor hindering its application. The above-mentioned disclosed method solves this problem to a certain extent, but it will also lead to an increase in manufacturing costs. Therefore, it is necessary to develop a preparation method for CuNiSn alloy material with simple and effective process, controllable production cost and excellent performance. Summary of the invention

[0009] The first technical problem to be solved by the present invention is to provide a high-strength copper alloy wire with excellent performance in view of the current status of the prior art.

[0010] The second technical problem to be solved by the present invention is to provide a method for preparing a high-strength copper alloy wire, so as to improve the segregation problem of alloy elements, simplify the process, improve production efficiency and reduce costs.

[0011] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a high-strength copper alloy wire, characterized in that it is composed of the following components in weight percentage: Ni: 17-18%, Sn: 3-4%, Al: 3-4%, Co: 0.5-1%, P: 0.05-0.1%, and the balance is Cu and inevitable impurities.

[0012] The copper alloy wire has a tensile strength of ≥1345 MPa, a yield strength of ≥1030 MPa, an elongation after fracture of ≥2%, and a hardness of ≥330 HV.

[0013] The technical solution adopted by the present invention to solve the above second technical problem is: a method for preparing the high-strength copper alloy wire as described above, characterized in that the steps are as follows:

[0014] 1) Induction melting: put the prepared raw materials: high-purity Cu, pure Ni block, pure Co block, Cu-P master alloy into an induction furnace and perform induction melting under the protection of N2 atmosphere. After the raw materials are completely melted, a melt is obtained. Then, pure Sn particles and pure Al blocks are added to the melt and kept at a temperature of 1270-1330°C for 6-8 minutes. Then, the induction melting power is reduced to 25-28KW for casting to obtain an ingot.

[0015] 2) Water-seal extrusion: the billet obtained in step 1) is cut into ends, and then placed in a heat-insulating furnace for homogenization, and then the billet is taken out for water-seal extrusion to obtain a copper alloy rod;

[0016] 3) rolling: subjecting the copper alloy rod obtained in step 2) to a multi-pass rolling process;

[0017] 4) Recrystallization annealing: the copper alloy rod after the rolling treatment in step 3) is subjected to atmosphere annealing treatment;

[0018] 5) Continuous drawing: The copper alloy rod after annealing in step 4) is subjected to multiple continuous drawing processes to obtain a copper alloy wire;

[0019] 6) Annealing treatment: performing atmosphere annealing treatment on the copper alloy wire obtained in step 5);

[0020] 7) Continuous drawing: subjecting the copper alloy wire after annealing in step 6) to multiple continuous drawing processes;

[0021] 8) Annealing treatment: The copper alloy wire after the continuous drawing treatment in step 7) is subjected to atmosphere annealing treatment to obtain a high-strength copper alloy wire.

[0022] The head cropping process is to cut off the portion of the billet head having shrinkage defects.

[0023] Preferably, in step 1), the casting mold is a copper mold with a release agent applied to the inner wall. The copper mold can greatly improve the cooling efficiency of the billet and reduce the proportion of the brittle Sn-rich area.

[0024] Furthermore, during the casting process, the casting speed in the later stage of casting is lower than the casting speed in the earlier stage of casting, so as to fill the shrinkage cavity defects of the casting, reduce the excess material of the head-cut part later, and improve the material utilization rate.

[0025] Preferably, in step 1), after the raw materials are completely melted, the temperature is kept at 1360-1450° C. for 15-20 minutes to obtain a melt.

[0026] Preferably, the temperature of the homogenization treatment in step 2) is 850-880° C., the holding time is 5-6 hours, the extrusion ratio is 11-13, and the extrusion speed is 24-30 m / s.

[0027] Preferably, the total deformation of rolling in step 3) is 55-65%, and the processing amount per pass is 5-10%; the total deformation of continuous drawing in step 5) is 65-70%, and the processing amount per pass is 5-10%; the total deformation of continuous drawing in step 7) is 60-70%, and the processing amount per pass is 5-10%.

[0028] Preferably, the recrystallization annealing system in step 4) is as follows: the copper alloy rod is charged into a furnace at room temperature, heated to 580-620° C. with the furnace, and kept at this temperature for 4-8 hours, and then cooled with the furnace, and the annealing atmosphere is N2;

[0029] Step 6) The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 500-540°C with the furnace, and kept at this temperature for 2-4 hours, and then cooled with the furnace, and the annealing atmosphere is N2;

[0030] Step 8) The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 430-460° C. with the furnace, and kept at this temperature for 1-2 hours, and then cooled with the furnace, and the annealing atmosphere is N2.

[0031] Compared with the prior art, the advantages of the present invention are: the mass fraction of the easily segregated element Sn is controlled within 4%, and red copper material with excellent thermal conductivity is used as a casting mold to achieve rapid cooling of the ingot, greatly reducing the proportion of brittle Sn-rich areas in the matrix; combined with water seal extrusion technology, it is ensured that the element Sn is distributed in the matrix in the form of solid solution, thereby improving the cold and hot processing properties of the alloy; at the same time, Ni, Co and Al elements are used to form a (Ni, Co)3Al high temperature resistant strengthening phase during the annealing process to improve the mechanical properties of the alloy; and in the preparation method of the present invention, the copper alloy rod is quickly cooled after water seal extrusion, which reduces the solid solution treatment link, thereby saving production costs and achieving the effect of solid solution treatment. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below with reference to the embodiments.

[0033] Embodiment 1:

[0034] The steps for preparing the high-strength copper alloy wire of this embodiment are as follows:

[0035] (1) Induction melting: Put the prepared raw materials: high-purity Cu, pure Ni block, pure Co block, Cu-P master alloy into an induction furnace and perform induction melting under the protection of N2 atmosphere. After the raw materials are completely melted, a melt is obtained. Then, pure Sn particles and pure Al blocks are added to the melt and kept at 1270°C for 8 minutes. Then, the induction melting power is reduced to 25KW for casting to obtain an ingot. The casting speed is slowed down in the later stage of casting. The casting mold is a copper mold, and a release agent is applied to the inner wall of the mold. The ingot is composed of the following components by weight percentage: Ni: 17%, Sn: 3%, Al: 3%, Co: 0.5%, P: 0.05%, and the balance is Cu and unavoidable impurities;

[0036] (2) Water-seal extrusion: the billet obtained in step (1) is subjected to head trimming treatment, and then placed in a holding furnace for homogenization treatment, the homogenization annealing temperature is 850° C., the holding time is 6 h, and then the billet is taken out for water-seal extrusion treatment, the extrusion ratio is 11, and the extrusion speed is 24 m / s, to obtain a copper alloy rod;

[0037] (3) rolling: the copper alloy rod obtained in step (2) is subjected to a multi-pass rolling process, wherein the total deformation of the rolling process is 55% and the processing amount of each pass is 5%;

[0038] (4) Recrystallization annealing: The copper alloy rod obtained in step (3) is subjected to atmosphere annealing treatment, and the annealing system is as follows: the copper alloy rod is placed in a furnace at room temperature, and the temperature is raised to 600°C (the heating rate is 5°C / min) with the furnace, and the temperature is kept for 6 hours, and then the temperature is lowered with the furnace, and the annealing atmosphere is N2;

[0039] (5) Continuous drawing: The copper alloy rod treated in step (4) is subjected to a plurality of continuous drawing processes to obtain a copper alloy wire, wherein the total deformation of the continuous drawing is 65% and the processing amount of each process is 5%;

[0040] (6) Annealing treatment: The copper alloy wire obtained in step (5) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 540°C (heating rate is 5°C / min), and kept at this temperature for 4 hours. Then, the temperature is lowered in the furnace. The annealing atmosphere is N2.

[0041] (7) Continuous drawing: The copper alloy wire treated in step (6) is subjected to a plurality of continuous drawing processes, wherein the total deformation of the continuous drawing is 60% and the processing amount of each process is 5%;

[0042] (8) Annealing treatment: The copper alloy wire obtained in step (7) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 460°C (heating rate is 5°C / min), and kept at this temperature for 2 h, and then cooled in the furnace. The annealing atmosphere is N2.

[0043] The copper alloy wire obtained in this example has a tensile strength of 1345 MPa, a yield strength of 1030 MPa, an elongation after fracture of 3%, and a hardness of 330 HV.

[0044] Embodiment 2:

[0045] The steps for preparing the high-strength copper alloy wire of this embodiment are as follows:

[0046] (1) Induction melting: Put the prepared raw materials: high-purity Cu, pure Ni block, pure Co block, Cu-P master alloy into an induction furnace and perform induction melting under the protection of N2 atmosphere. After the raw materials are completely melted, a melt is obtained. Then, pure Sn particles and pure Al blocks are added to the melt and kept at 1330°C for 6 minutes. Then, the induction melting power is reduced to 27KW for casting to obtain an ingot. The casting speed is slowed down in the later stage of casting. The casting mold is a copper mold, and a release agent is applied to the inner wall of the mold. The ingot is composed of the following components by weight percentage: Ni: 17.5%, Sn: 3.5%, Al: 4%, Co: 0.5%, P: 0.08%, and the balance is Cu and unavoidable impurities;

[0047] (2) Water-seal extrusion: the billet obtained in step (1) is subjected to head cutting, and then placed in a holding furnace for homogenization treatment, the homogenization annealing temperature is 850° C., the holding time is 6 h, and then the billet is taken out for water-seal extrusion treatment, the extrusion ratio is 12, and the extrusion speed is 26 m / s, to obtain a copper alloy rod;

[0048] (3) rolling: the copper alloy rod obtained in step (2) is subjected to a multi-pass rolling process, wherein the total deformation of the rolling process is 60% and the processing amount of each pass is 5%;

[0049] (4) Recrystallization annealing: The copper alloy rod obtained in step (3) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy rod is placed in a furnace at room temperature, heated to 580°C (heating rate is 5°C / min), and kept at this temperature for 8 hours, and then cooled in the furnace. The annealing atmosphere is N2;

[0050] (5) Continuous drawing: The copper alloy rod treated in step (4) is subjected to a plurality of continuous drawing processes to obtain a copper alloy wire, wherein the total deformation of the continuous drawing is 65% and the processing amount of each process is 5%;

[0051] (6) Annealing: The copper alloy wire obtained in step (5) is subjected to atmosphere annealing. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 500°C (at a heating rate of 5°C / min) and kept at this temperature for 4 hours, then cooled in the furnace. The annealing atmosphere is N2.

[0052] (7) Continuous drawing: The copper alloy wire treated in step (6) is subjected to a plurality of continuous drawing processes, wherein the total deformation of the continuous drawing is 70% and the processing amount of each process is 5%;

[0053] (8) Annealing treatment: The copper alloy wire obtained in step (7) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 450°C (heating rate is 5°C / min), and kept at this temperature for 1.5 h. The temperature is then lowered in the furnace. The annealing atmosphere is N2.

[0054] The copper alloy wire obtained in this example has a tensile strength of 1362 MPa, a yield strength of 1051 MPa, an elongation after fracture of 3%, and a hardness of 332 HV.

[0055] Embodiment 3:

[0056] The steps for preparing the high-strength copper alloy wire of this embodiment are as follows:

[0057] (1) Induction melting: Put the prepared raw materials: high-purity Cu, pure Ni block, pure Co block, Cu-P master alloy into an induction furnace and perform induction melting under the protection of N2 atmosphere. After the raw materials are completely melted, a melt is obtained. Then, pure Sn particles and pure Al blocks are added to the melt and kept at 1300°C for 7 minutes. Then, the induction melting power is reduced to 27KW for casting to obtain an ingot. The casting speed is slowed down in the later stage of casting. The casting mold is a copper mold, and a release agent is applied to the inner wall of the mold. The ingot is composed of the following components by weight percentage: Ni: 17.5%, Sn: 3.5%, Al: 3.5%, Co: 0.7%, P: 0.08%, and the balance is Cu and unavoidable impurities;

[0058] (2) Water-seal extrusion: the billet obtained in step (1) is subjected to head trimming, and then placed in a holding furnace for homogenization treatment, the homogenization annealing temperature is 870° C., the holding time is 5 h, and then the billet is taken out for water-seal extrusion treatment, the extrusion ratio is 12, and the extrusion speed is 26 m / s, to obtain a copper alloy rod;

[0059] (3) rolling: the copper alloy rod obtained in step (2) is subjected to a multi-pass rolling process, wherein the total deformation of the rolling process is 60% and the processing amount of each pass is 5%;

[0060] (4) Recrystallization annealing: The copper alloy rod obtained in step (3) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy rod is placed in a furnace at room temperature, heated to 620°C (heating rate is 5°C / min), and kept at this temperature for 4 hours, and then cooled in the furnace. The annealing atmosphere is N2;

[0061] (5) Continuous drawing: The copper alloy rod treated in step (4) is subjected to a plurality of continuous drawing processes to obtain a copper alloy wire, wherein the total deformation amount of the continuous drawing is 70% and the processing amount of each process is 10%;

[0062] (6) Annealing treatment: The copper alloy wire obtained in step (5) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 520°C (heating rate is 5°C / min), and kept at this temperature for 3 hours, and then cooled in the furnace. The annealing atmosphere is N2;

[0063] (7) Continuous drawing: The copper alloy wire treated in step (6) is subjected to multiple continuous drawing processes, wherein the total deformation of the continuous drawing is 64% and the processing amount of each process is 8%;

[0064] (8) Annealing treatment: The copper alloy wire obtained in step (7) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 430°C (heating rate is 5°C / min), and kept at this temperature for 2 h, and then cooled in the furnace. The annealing atmosphere is N2.

[0065] The copper alloy wire obtained in this example has a tensile strength of 1358 MPa, a yield strength of 1055 MPa, an elongation after fracture of 3%, and a hardness of 331 HV.

[0066] Embodiment 4:

[0067] The steps for preparing the high-strength copper alloy wire of this embodiment are as follows:

[0068] (1) Induction melting: Put the prepared raw materials: high-purity Cu, pure Ni block, pure Co block, Cu-P master alloy into an induction furnace and perform induction melting under the protection of N2 atmosphere. After the raw materials are completely melted, a melt is obtained. Then, pure Sn particles and pure Al blocks are added to the melt and kept at 1300°C for 6 minutes. Then, the induction melting power is reduced to 27KW for casting to obtain an ingot. The casting speed is slowed down in the later stage of casting. The casting mold is a copper mold, and a release agent is applied to the inner wall of the mold. The ingot is composed of the following components by weight percentage: Ni: 17%, Sn: 3%, Al: 3.5%, Co: 0.7%, P: 0.05%, and the balance is Cu and unavoidable impurities;

[0069] (2) Water-seal extrusion: the billet obtained in step (1) is subjected to head trimming, and then placed in a holding furnace for homogenization treatment, the homogenization annealing temperature is 870° C., the holding time is 5 h, and then the billet is taken out for water-seal extrusion treatment, the extrusion ratio is 11, and the extrusion speed is 30 m / s, to obtain a copper alloy rod;

[0070] (3) rolling: the copper alloy rod obtained in step (2) is subjected to a multi-pass rolling process, wherein the total deformation of the rolling process is 60% and the processing amount of each pass is 10%;

[0071] (4) Recrystallization annealing: The copper alloy rod obtained in step (3) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy rod is placed in a furnace at room temperature, heated to 600°C (heating rate is 5°C / min), and kept at this temperature for 6 hours. Then, the temperature is lowered in the furnace. The annealing atmosphere is N2.

[0072] (5) Continuous drawing: The copper alloy rod treated in step (4) is subjected to a plurality of continuous drawing processes to obtain a copper alloy wire, wherein the total deformation amount of the continuous drawing is 70% and the processing amount of each process is 7%;

[0073] (6) Annealing treatment: The copper alloy wire obtained in step (5) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 540°C (heating rate is 5°C / min), and kept at this temperature for 2 hours. Then, the temperature is lowered in the furnace. The annealing atmosphere is N2.

[0074] (7) Continuous drawing: The copper alloy wire treated in step (6) is subjected to a plurality of continuous drawing processes, wherein the total deformation of the continuous drawing is 60% and the processing amount of each process is 10%;

[0075] (8) Annealing treatment: The copper alloy wire obtained in step (7) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 430°C (heating rate is 5°C / min), and kept at this temperature for 2 h, and then cooled in the furnace. The annealing atmosphere is N2.

[0076] The copper alloy wire obtained in this example has a tensile strength of 1379 MPa, a yield strength of 1043 MPa, an elongation after fracture of 2%, and a hardness of 337 HV.

[0077] Embodiment 5:

[0078] The steps for preparing the high-strength copper alloy wire of this embodiment are as follows:

[0079] (1) Induction melting: Put the prepared raw materials: high-purity Cu, pure Ni block, pure Co block, Cu-P master alloy into an induction furnace and perform induction melting under the protection of N2 atmosphere. After the raw materials are completely melted, a melt is obtained. Then, pure Sn particles and pure Al blocks are added to the melt and kept at 1330°C for 8 minutes. Then, the induction melting power is reduced to 28KW for casting to obtain an ingot. The casting speed is slowed down in the later stage of casting. The casting mold is a copper mold, and a release agent is applied to the inner wall of the mold. The ingot is composed of the following components by weight percentage: Ni: 18%, Sn: 4%, Al: 4%, Co: 1%, P: 0.1%, and the balance is Cu and unavoidable impurities;

[0080] (2) Water-seal extrusion: the billet obtained in step (1) is subjected to head cutting, and then placed in a holding furnace for homogenization treatment, the homogenization annealing temperature is 880° C., the holding time is 6 h, and then the billet is taken out for water-seal extrusion treatment, the extrusion ratio is 13, and the extrusion speed is 28 m / s, to obtain a copper alloy rod;

[0081] (3) rolling: the copper alloy rod obtained in step (2) is subjected to a multi-pass rolling process, wherein the total deformation of the rolling process is 65% and the processing amount of each pass is 5%;

[0082] (4) Recrystallization annealing: The copper alloy rod obtained in step (3) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy rod is placed in a furnace at room temperature, heated to 600°C (heating rate is 5°C / min), and kept at this temperature for 6 hours. Then, the temperature is lowered in the furnace. The annealing atmosphere is N2.

[0083] (5) Continuous drawing: The copper alloy rod treated in step (4) is subjected to multiple continuous drawing processes to obtain a copper alloy wire, wherein the total deformation amount of the continuous drawing is 70% and the processing amount of each process is 7%;

[0084] (6) Annealing: The copper alloy wire obtained in step (5) is subjected to atmosphere annealing. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 500°C (at a heating rate of 5°C / min) and kept at this temperature for 4 hours, then cooled in the furnace. The annealing atmosphere is N2.

[0085] (7) Continuous drawing: The copper alloy wire treated in step (6) is subjected to a plurality of continuous drawing processes, wherein the total deformation of the continuous drawing is 70% and the processing amount of each process is 5%;

[0086] (8) Annealing treatment: The copper alloy wire obtained in step (7) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 430°C (heating rate is 5°C / min), and kept at this temperature for 2 h, and then cooled in the furnace. The annealing atmosphere is N2.

[0087] The copper alloy wire obtained in this example has a tensile strength of 1431 MPa, a yield strength of 1094 MPa, an elongation after fracture of 2%, and a hardness of 342 HV.

[0088] Embodiment 6:

[0089] The steps for preparing the high-strength copper alloy wire of this embodiment are as follows:

[0090] (1) Induction melting: Put the prepared raw materials: high-purity Cu, pure Ni block, pure Co block, Cu-P master alloy into an induction furnace and perform induction melting under the protection of N2 atmosphere. After the raw materials are completely melted, a melt is obtained. Then, pure Sn particles and pure Al blocks are added to the melt and kept at 1330°C for 8 minutes. Then, the induction melting power is reduced to 28KW for casting to obtain an ingot. The casting speed is slowed down in the later stage of casting. The casting mold is a copper mold, and a release agent is applied to the inner wall of the mold. The ingot is composed of the following components by weight percentage: Ni: 18%, Sn: 3%, Al: 3%, Co: 1%, P: 0.1%, and the balance is Cu and unavoidable impurities;

[0091] (2) Water-seal extrusion: the billet obtained in step (1) is subjected to head trimming treatment, and then placed in a holding furnace for homogenization treatment, the homogenization annealing temperature is 880° C., the holding time is 6 h, and then the billet is taken out for water-seal extrusion treatment, the extrusion ratio is 12, and the extrusion speed is 26 m / s, to obtain a copper alloy rod;

[0092] (3) rolling: the copper alloy rod obtained in step (2) is subjected to a multi-pass rolling process, wherein the total deformation of the rolling process is 64% and the processing amount of each pass is 8%;

[0093] (4) Recrystallization annealing: The copper alloy rod obtained in step (3) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy rod is placed in a furnace at room temperature, heated to 620°C (heating rate is 5°C / min), and kept at this temperature for 6 hours, and then cooled in the furnace. The annealing atmosphere is N2;

[0094] (5) Continuous drawing: The copper alloy rod treated in step (4) is subjected to a plurality of continuous drawing processes to obtain a copper alloy wire, wherein the total deformation of the continuous drawing is 70% and the processing amount of each process is 5%;

[0095] (6) Annealing treatment: The copper alloy wire obtained in step (5) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 520°C (heating rate is 5°C / min), and kept at this temperature for 4 hours, and then cooled in the furnace. The annealing atmosphere is N2;

[0096] (7) Continuous drawing: The copper alloy wire treated in step (6) is subjected to multiple continuous drawing processes, wherein the total deformation of the continuous drawing is 64% and the processing amount of each process is 8%;

[0097] (8) Annealing: The copper alloy wire obtained in step (7) is subjected to atmosphere annealing. The annealing process is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 450°C (at a heating rate of 5°C / min) and kept at this temperature for 2 h, then cooled in the furnace. The annealing atmosphere is N2.

[0098] The copper alloy wire obtained in this example has a tensile strength of 1372 MPa, a yield strength of 1068 MPa, an elongation after fracture of 3%, and a hardness of 335 HV.

[0099] Embodiment 7:

[0100] The steps for preparing the high-strength copper alloy wire of this embodiment are as follows:

[0101] (1) Induction melting: Put the prepared raw materials: high-purity Cu, pure Ni block, pure Co block, Cu-P master alloy into an induction furnace and perform induction melting under the protection of N2 atmosphere. After the raw materials are completely melted, a melt is obtained. Then, pure Sn particles and pure Al blocks are added to the melt and kept at 1300°C for 8 minutes. Then, the induction melting power is reduced to 26KW for casting to obtain an ingot. The casting speed is slowed down in the later stage of casting. The casting mold is a copper mold, and a release agent is applied to the inner wall of the mold. The ingot is composed of the following components by weight percentage: Ni: 17%, Sn: 4%, Al: 3%, Co: 0.5%, P: 0.05%, and the balance is Cu and unavoidable impurities;

[0102] (2) Water-seal extrusion: the billet obtained in step (1) is subjected to head trimming, and then placed in a holding furnace for homogenization treatment, the homogenization annealing temperature is 880° C., the holding time is 5 h, and then the billet is taken out for water-seal extrusion treatment, the extrusion ratio is 12, and the extrusion speed is 28 m / s, to obtain a copper alloy rod;

[0103] (3) rolling: the copper alloy rod obtained in step (2) is subjected to a multi-pass rolling process, wherein the total deformation of the rolling process is 64% and the processing amount of each pass is 8%;

[0104] (4) Recrystallization annealing: The copper alloy rod obtained in step (3) is subjected to atmosphere annealing treatment. The annealing system is as follows: the copper alloy rod is placed in a furnace at room temperature, heated to 580°C (heating rate is 5°C / min), and kept at this temperature for 8 hours, and then cooled in the furnace. The annealing atmosphere is N2;

[0105] (5) Continuous drawing: The copper alloy rod treated in step (4) is subjected to a plurality of continuous drawing processes to obtain a copper alloy wire, wherein the total deformation of the continuous drawing is 65% and the processing amount of each process is 5%;

[0106] (6) Annealing: The copper alloy wire obtained in step (5) is subjected to atmosphere annealing. The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 500°C (at a heating rate of 5°C / min) and kept at this temperature for 4 hours, then cooled in the furnace. The annealing atmosphere is N2.

[0107] (7) Continuous drawing: The copper alloy wire treated in step (6) is subjected to a plurality of continuous drawing processes, wherein the total deformation of the continuous drawing is 70% and the processing amount of each process is 5%;

[0108] (8) Annealing: The copper alloy wire obtained in step (7) is subjected to atmosphere annealing. The annealing process is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 450°C (at a heating rate of 5°C / min) and kept at this temperature for 1 h, then cooled in the furnace. The annealing atmosphere is N2.

[0109] The copper alloy wire obtained in this example has a tensile strength of 1393 MPa, a yield strength of 1052 MPa, an elongation after fracture of 2%, and a hardness of 337 HV.

[0110] The above specific embodiments are further detailed descriptions of the present invention, and it cannot be determined that the specific implementation methods of the present invention are limited to these. Without departing from the alloy composition range and preparation steps proposed in the present invention, appropriate composition adjustments and improvements can be made, but they should all be deemed to belong to the protection scope of the claims submitted by the present invention.

Claims

1. A high-strength copper alloy wire, characterized in that: The invention is composed of the following components in weight percentage: Ni: 17-18%, Sn: 3-4%, Al: 3-4%, Co: 0.5-1%, P: 0.05-0.1%, and the balance is Cu and inevitable impurities.

2. The high-strength copper alloy wire according to claim 1, characterized in that: The copper alloy wire has a tensile strength of ≥1345 MPa, a yield strength of ≥1030 MPa, an elongation after fracture of ≥2%, and a hardness of ≥330 HV.

3. A method for preparing a high-strength copper alloy wire as claimed in claim 1 or 2, characterized in that Here are the steps: 1) Induction melting: put the prepared raw materials: high-purity Cu, pure Ni block, pure Co block, Cu-P master alloy into an induction furnace and perform induction melting under the protection of N2 atmosphere. After the raw materials are completely melted, a melt is obtained. Then, pure Sn particles and pure Al blocks are added to the melt and kept at a temperature of 1270-1330°C for 6-8 minutes. Then, the induction melting power is reduced to 25-28KW for casting to obtain an ingot. 2) Water-seal extrusion: the billet obtained in step 1) is cut into ends, and then placed in a heat-insulating furnace for homogenization, and then the billet is taken out for water-seal extrusion to obtain a copper alloy rod; 3) rolling: subjecting the copper alloy rod obtained in step 2) to a multi-pass rolling process; 4) Recrystallization annealing: the copper alloy rod after the rolling treatment in step 3) is subjected to atmosphere annealing treatment; 5) Continuous drawing: The copper alloy rod after annealing in step 4) is subjected to multiple continuous drawing processes to obtain a copper alloy wire; 6) Annealing treatment: performing atmosphere annealing treatment on the copper alloy wire obtained in step 5); 7) Continuous drawing: subjecting the copper alloy wire after annealing in step 6) to multiple continuous drawing processes; 8) Annealing treatment: The copper alloy wire after the continuous drawing treatment in step 7) is subjected to atmosphere annealing treatment to obtain a high-strength copper alloy wire.

4. The preparation method according to claim 3, characterized in that: In step 1), the casting mold is a copper mold with a release agent applied to the inner wall.

5. The preparation method according to claim 4, characterized in that: During the casting process, the casting speed in the later stage of casting is lower than that in the earlier stage of casting (to make up for the shrinkage defects of casting).

6. The preparation method according to claim 3, characterized in that: In step 1), after the raw materials are completely melted, the temperature is kept at 1360-1450° C. for 15-20 minutes to obtain a melt.

7. The preparation method according to claim 3, characterized in that: In step 2), the temperature of the homogenization treatment is 850-880° C., the holding time is 5-6 hours, the extrusion ratio is 11-13, and the extrusion speed is 24-30 m / s.

8. The preparation method according to claim 3, characterized in that: The total deformation of rolling in step 3) is 55-65%, and the processing amount per pass is 5-10%; the total deformation of continuous drawing in step 5) is 65-70%, and the processing amount per pass is 5-10%; the total deformation of continuous drawing in step 7) is 60-70%, and the processing amount per pass is 5-10%.

9. The preparation method according to claim 3, characterized in that: Step 4) The recrystallization annealing system is as follows: the copper alloy rod is placed in a furnace at room temperature, heated to 580-620°C with the furnace, and kept at this temperature for 4-8 hours, and then cooled with the furnace, and the annealing atmosphere is N2; Step 6) The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 500-540°C with the furnace, and kept at this temperature for 2-4 hours, and then cooled with the furnace, and the annealing atmosphere is N2; Step 8) The annealing system is as follows: the copper alloy wire is placed in a furnace at room temperature, heated to 430-460° C. with the furnace, and kept at this temperature for 1-2 hours, and then cooled with the furnace, and the annealing atmosphere is N2.