Cu-Ni-P series alloy strip and manufacturing method and application thereof

Abstract

The invention discloses a Cu-Ni-P series alloy strip and a manufacturing method and application, and relates to the technical field of copper alloys, and the manufacturing method of the Cu-Ni-P series alloy strip comprises the following steps of upward continuous casting, homogenization heat treatment, continuous plate blank extrusion, primary cold rolling, two-stage aging heat treatment and secondary cold rolling. The manufacturing method provided by the invention is short in process and low in cost, and the Cu-Ni-P series alloy strip provided by the invention has excellent strength, conductivity and bending performance.

Description

Technical Field

[0001] The invention relates to the technical field of copper alloys, in particular to a Cu-Ni-P alloy strip and a manufacturing method and application thereof. Background Art

[0002] Copper alloys are widely used in electrical transmission systems in various industries due to their excellent electrical conductivity and mechanical properties. In recent years, the rapid development of industries such as integrated circuits, rail transportation, aerospace, and communications has put forward higher requirements for the electrical conductivity and strength of copper alloys. At present, the development of high-strength and high-conductivity copper alloys mainly depends on the precipitation strengthening of the alloy. The precipitation of the precipitated phase purifies the matrix, and on the premise of greatly improving the electrical conductivity and thermal conductivity, the strength of the alloy can be improved by hindering the movement of dislocations by the precipitated phase.

[0003] Commercial high-strength and high-conductivity copper alloys are mainly Cu-Cr-Zr alloys and Cu-Ni-Si alloys. The tensile strength of Cu-Cr-Zr alloys is about 500-580MPa, and the conductivity is about 75%-85%. The conductivity is excellent, but the strength is low; the tensile strength of Cu-Ni-Si alloys is about 550-950MPa, and the conductivity is about 35%-55%. The strength is high, but the conductivity is poor. Cu-Ni-P alloys rely on the extremely low solid solubility of Ni-P phase in the Cu matrix and the significant precipitation strengthening effect to make their tensile strength reach more than 600MPa, and the conductivity reaches more than 60%. It is a high-strength and high-conductivity copper alloy with excellent performance, and has huge market prospects in the fields of lead frames, connectors, etc. However, the production process of Cu-Ni-P alloy adopts the process route of semi-continuous casting - walking furnace heating - hot rolling - milling - first cold rolling - air cushion furnace solution heat treatment - second cold rolling - aging heat treatment - third cold rolling. The process flow is long, the yield rate is low, and the production cost is high, resulting in its high price.

[0004] In response to a series of problems in the current copper alloy strip field, it is urgently necessary to develop a short-process, low-cost manufacturing method to produce Cu-Ni-P alloys with excellent strength and conductivity, so as to achieve large-scale promotion of high-strength and high-conductivity copper alloys and promote the upgrading of various industries. Summary of the invention

[0005] Based on this, the purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a Cu-Ni-P alloy strip and a manufacturing method and application. The manufacturing method provided by the present invention has a short process and low cost, and the Cu-Ni-P alloy strip provided by the present invention has excellent strength and electrical conductivity.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for manufacturing a Cu-Ni-P alloy strip, comprising the following steps: upward continuous casting → homogenization heat treatment → continuous extrusion of slabs → primary cold rolling → two-stage aging heat treatment → secondary cold rolling;

[0007] (1) Using a copper alloy as a raw material, a copper alloy casting rod is prepared by an upward continuous casting process; the copper alloy comprises the following components in percentage by weight: Ni: 0.3-1.3wt%, P: 0.05-0.3%, impurities ≤ 0.4%, copper: balance, and the mass percentage ratio of Ni to P is 3.0-5.5;

[0008] (2) subjecting the copper alloy cast rod to homogenization heat treatment and continuous extrusion to prepare an extruded slab;

[0009] (3) The extruded slab is subjected to a primary cold rolling, a two-stage aging heat treatment, and a secondary cold rolling process in sequence to obtain the Cu-Ni-P alloy strip; the total deformation in the primary cold rolling is 70-95%; in the two-stage aging process, the primary aging temperature is 200-300°C, the aging time is 3-6h, and the secondary aging is 300-500°C, and the aging time is 1-4h; the total deformation in the secondary cold rolling is 40-70%.

[0010] Compared with the existing upward casting-continuous extrusion technology, the present invention first performs homogenization heat treatment on the copper alloy casting rod prepared by the upward continuous casting process to eliminate grain boundary segregation, fully dissolve the Ni-P crystalline phase, and then perform the subsequent continuous extrusion process. The present invention limits the element content of the copper alloy raw material in the upward continuous casting process, and further limits the mass percentage ratio of the Ni and P. The element content of the copper alloy raw material has a great influence on the final performance. When the mass ratio of Ni to P elements is close to 4.74, the solid solubility of Ni and P elements is greatly reduced, which provides favorable conditions for improving the strength and conductivity of the alloy through precipitation strengthening, but also increases the difficulty of solid solution of Ni and P elements. Without high-temperature homogenization treatment of the ingot, it is difficult to completely dissolve the Ni-P crystalline phase in the solidification process by relying only on the short-term high-temperature solid solution of continuous extrusion. A small amount of Ni-P phase will precipitate during the cooling process of the homogenization heat treatment of the present invention, but because the precipitated phase is small in size and small in number, the precipitated phase can be dissolved back by short-term high-temperature heating in continuous extrusion to obtain a high solid solubility structure.

[0011] The extruded slab prepared by the present invention in a continuous extrusion method contains a fine dynamic recrystallization structure to provide a higher grain boundary density. At the same time, a large deformation (70-95% deformation) is applied during a cold rolling process to obtain a high density of dislocations in the metal crystal and improve the precipitation dynamics. In addition, the aging annealing of the present invention adopts a two-stage aging heat treatment, a first-stage low-temperature long-time aging to obtain a high-density Ni-P cluster, and a second-stage high-temperature short-time aging to generate a large amount of precipitated phases, which greatly improves the density of the Ni-P precipitated phase in the alloy after the aging heat treatment, so that the alloy has excellent strength and conductivity.

[0012] Preferably, in step (1), the casting temperature in the upward continuous casting is 1160-1200° C., and the diameter of the cast rod is 25-30 mm.

[0013] Preferably, in step (2), the heat treatment temperature in the homogenization heat treatment is 850-900°C, and the heat treatment time is 3-5h; the extrusion wheel speed in the continuous extrusion slab is 3-5r / min, and the extrusion die preheating temperature is 450-650°C.

[0014] Preferably, in step (2), the thickness of the extruded slab prepared after continuous extrusion is 12-14 mm.

[0015] The thickness of the continuously extruded slab of the present invention is relatively thin, and it is immediately water quenched after being extruded from the cavity. The elements dissolved in the water quenching and cooling process are far less than those in the traditional hot rolling process. Subsequently, aging heat treatment can be performed without solid solution in an air cushion furnace, which shortens the process flow and reduces production costs.

[0016] Preferably, in the step (3), the thickness of the Cu-Ni-P alloy strip obtained after sequentially performing the first cold rolling, the two-stage aging heat treatment and the second cold rolling process is 0.2-1.5 mm.

[0017] Furthermore, the present invention also provides a Cu-Ni-P alloy strip manufactured by the method for manufacturing the Cu-Ni-P alloy strip.

[0018] In addition, the present invention also provides the application of the Cu-Ni-P alloy strip in the fields of integrated circuits, rail transportation, aerospace, and communications.

[0019] Preferably, the present invention provides the use of the Cu-Ni-P alloy strip in lead frames, automotive connectors, and ultra-thin heat sinks.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: compared with the existing upward casting-continuous extrusion technology, the present invention first performs homogenization heat treatment on the copper alloy casting rod prepared by the upward continuous casting process, eliminates grain boundary segregation, fully dissolves the Ni-P crystalline phase, and then performs the subsequent continuous extrusion process. The present invention limits the element content of the copper alloy raw material in the upward continuous casting process, and further limits the mass percentage ratio of the Ni and P. The inventor found in the actual experimental process that the element content of the copper alloy raw material has a great influence on the final performance. When the mass ratio of Ni to P elements is close to 4.74, the solid solubility of Ni and P elements will be greatly reduced, which increases the difficulty of solid solution of Ni and P elements. If the ingot is not subjected to high-temperature homogenization treatment, it is difficult to completely dissolve the Ni-P crystalline phase in the solidification process by relying only on the short-term high-temperature solid solution of continuous extrusion. A small amount of Ni-P phase will precipitate during the cooling process of the homogenization heat treatment of the present invention, but because the precipitated phase is small in size and small in number, the precipitated phase can be dissolved back by short-term high-temperature heating in continuous extrusion to obtain a high solid solubility structure.

[0021] The extruded slab prepared by the present invention in a continuous extrusion method contains a fine dynamic recrystallization structure to provide a higher grain boundary density. At the same time, a large deformation (70-95% deformation) is applied during a cold rolling process to obtain a high density of dislocations in the metal crystal and improve the precipitation dynamics. In addition, the aging annealing of the present invention adopts a two-stage aging heat treatment, a first-stage low-temperature long-time aging to obtain a high-density Ni-P cluster, and a second-stage high-temperature short-time aging to generate a large amount of precipitated phases, which greatly improves the density of the Ni-P precipitated phase in the alloy after the aging heat treatment, so that the alloy has excellent strength and conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 are microscopic morphology images of Cu-Ni-P alloy strips; wherein (a) is a microscopic morphology image of the Cu-Ni-P alloy strip prepared in Comparative Example 3, and (b) is a microscopic morphology image of the Cu-Ni-P alloy strip prepared in Example 1;

[0023] Figure 2 TEM images of Cu-Ni-P alloy strips; wherein (a) is the TEM image of the Cu-Ni-P alloy strip prepared in Comparative Example 7, and (b) is the TEM image of the Cu-Ni-P alloy strip prepared in Example 1. DETAILED DESCRIPTION

[0024] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Its purpose is to understand the content of the present invention in detail, rather than to limit the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise specified, the experimental reagents and instruments designed for the implementation and comparative examples of the present invention are all commonly used ordinary reagents and instruments, which can be obtained from commercial channels. In the implementation and comparative examples, the experimental methods used are conventional methods unless otherwise specified; and unless otherwise specified, the raw materials used in parallel experiments are the same batch of raw materials.

[0025] The raw copper alloy used in the present invention is prepared by mixing electrolytic copper as raw material, pure Ni and copper-phosphorus master alloy, wherein the electrolytic copper comes from Jiangxi Copper Co., Ltd., the pure Ni comes from Tianjin Hejifeng Metal Materials Co., Ltd., and the copper-phosphorus master alloy comes from Suzhou Antibot Metal Products Co., Ltd.

[0026] A method for manufacturing a Cu-Ni-P alloy strip comprises the following steps: upward continuous casting → homogenization heat treatment → continuous extrusion of slabs → primary cold rolling → double-stage aging heat treatment → secondary cold rolling;

[0027] (1) Using a copper alloy as a raw material, a copper alloy casting rod is prepared by an upward continuous casting process; the copper alloy comprises the following components in percentage by weight: Ni: 0.3-1.3wt%, P: 0.05-0.3%, impurities ≤ 0.4%, copper: balance, and the mass percentage ratio of Ni to P is 3.0-5.5; the casting temperature in the upward continuous casting is 1160-1200° C., and the diameter of the casting rod is 25-30 mm;

[0028] (2) subjecting the copper alloy cast rod to homogenization heat treatment and continuous extrusion to prepare an extruded slab; the heat treatment temperature in the homogenization heat treatment is 850-900°C, and the heat treatment time is 3-5h; the extrusion wheel speed in the continuous extrusion of the slab is 3-5r / min, and the extrusion die preheating temperature is 450-650°C; in the step (2), the extruded slab prepared after continuous extrusion has a thickness of 12-14mm;

[0029] (3) The extruded slab is subjected to a primary cold rolling, a two-stage aging heat treatment, and a secondary cold rolling process in sequence to obtain the Cu-Ni-P alloy strip; the total deformation in the primary cold rolling is 70-95%; in the two-stage aging process, the primary aging temperature is 200-300°C, the aging time is 3-6h, and the secondary aging is 300-500°C, and the aging time is 1-4h; the total deformation in the secondary cold rolling is 40-70%; the thickness of the Cu-Ni-P alloy strip obtained after the primary cold rolling, the two-stage aging heat treatment, and the secondary cold rolling process is 0.2-1.5mm.

[0030] Example 1

[0031] A method for manufacturing a Cu-Ni-P alloy strip comprises the following steps: upward continuous casting → homogenization heat treatment → continuous extrusion of slabs → primary cold rolling → double-stage aging heat treatment → secondary cold rolling;

[0032] (1) A copper alloy casting rod is prepared by using a copper alloy as a raw material and an upward continuous casting process; the copper alloy comprises the following components in percentage by weight: Ni: 0.9wt%, P: 0.2%, impurities ≤ 0.4%, copper: balance, and the ratio of the mass percentage of Ni to P is 4.5; the casting temperature in the upward continuous casting is 1180° C., and the diameter of the casting rod is 25 mm;

[0033] (2) subjecting the copper alloy cast rod to homogenization heat treatment and continuous extrusion to prepare an extruded slab; the heat treatment temperature in the homogenization heat treatment is 860° C., and the heat treatment time is 4 h; the extrusion wheel speed in the continuous extrusion of the slab is 3.5 r / min, and the extrusion die preheating temperature is 500° C.; in the step (2), the thickness of the extruded slab prepared after continuous extrusion is 12.6 mm;

[0034] (3) The extruded slab is subjected to a primary cold rolling, a two-stage aging heat treatment, and a secondary cold rolling process in sequence to obtain the Cu-Ni-P alloy strip; the total deformation in the primary cold rolling is 85%; in the two-stage aging process, the primary aging temperature is 280°C, the aging time is 3h, and the secondary aging is 400°C, and the aging time is 1.5h; the total deformation in the secondary cold rolling is 60%.

[0035] Example 2

[0036] Compared with Example 1, only the raw materials in step (1) are different. The copper alloy raw material used includes the following components in mass percentage: Ni: 1.3wt%, P: 0.25%, impurities ≤0.4%, copper: balance, the mass percentage ratio of Ni to P is 5.2, and the other components, amounts and preparation methods are exactly the same.

[0037] Example 3

[0038] Compared with Example 1, only the raw materials in step (1) are different. The copper alloy raw material used includes the following components in mass percentage: Ni: 0.55wt%, P: 0.15%, impurities ≤0.4%, copper: balance, and the mass percentage ratio of Ni to P is 3.67. The other components, amounts and preparation methods are exactly the same.

[0039] Example 4

[0040] Compared with Example 1, only the heat treatment temperature and time in the homogenization heat treatment of step (2) are different, the heat treatment temperature is 900° C., and the heat treatment time is 3 h. The other components, amounts and preparation methods are exactly the same.

[0041] Example 5

[0042] Compared with Example 1, only the speed of the extrusion wheel in step (2) is different, that is, the speed of the extrusion wheel is 5 r / min, and the other components, amounts and preparation methods are exactly the same.

[0043] Example 6

[0044] Compared with Example 1, only the extrusion die preheating temperature in step (2) is different, which is 650° C., and the other components, amounts and preparation methods are exactly the same.

[0045] Example 7

[0046] Compared with Example 1, only the total deformation amount in the first cold rolling of step (3) is different, and the total deformation amount in the first cold rolling is 95%. The other components, amounts and preparation methods are exactly the same.

[0047] Example 8

[0048] Compared with Example 1, only the total deformation amount in the first cold rolling of step (3) is different, that is, the total deformation amount in the first cold rolling is 70%, and the other components, amounts and preparation methods are exactly the same.

[0049] Example 9

[0050] Compared with Example 1, only the two-stage aging process parameters of step (3) are different, the primary aging temperature is 220° C., the aging time is 6 h, the secondary aging is 350° C., and the aging time is 4 h. The other components, amounts and preparation methods are exactly the same.

[0051] Example 10

[0052] Compared with Example 1, only the total deformation amount in the secondary cold rolling in step (3) is different, and the total deformation amount in the secondary cold rolling is 40%. The other components, amounts and preparation methods are exactly the same.

[0053] Embodiment 11

[0054] Compared with Example 1, only the total deformation amount in the secondary cold rolling in step (3) is different, and the total deformation amount in the secondary cold rolling is 70%. The other components, amounts and preparation methods are exactly the same.

[0055] Comparative Example 1

[0056] Compared with Example 1, only the raw materials in step (1) are different. The copper alloy raw material used includes the following components in mass percentage: Ni: 0.9wt%, P: 0.45%, impurities ≤0.4%, copper: balance, the mass percentage ratio of Ni to P is 2, and the other components, amounts and preparation methods are exactly the same.

[0057] Comparative Example 2

[0058] Compared with Example 1, only the raw materials in step (1) are different. The copper alloy raw material used includes the following components in mass percentage: Ni: 1.2wt%, P: 0.15%, impurities ≤0.4%, copper: balance, the mass percentage ratio of Ni to P is 8, and the other components, amounts and preparation methods are exactly the same.

[0059] Comparative Example 3

[0060] Compared with Example 1, only the homogenization heat treatment is not performed. Specifically, the preparation method is as follows:

[0061] A method for manufacturing a Cu-Ni-P alloy strip comprises the following steps: upward continuous casting → continuous extrusion of slabs → primary cold rolling → two-stage aging heat treatment → secondary cold rolling;

[0062] (1) A copper alloy casting rod is prepared by using a copper alloy as a raw material and an upward continuous casting process; the copper alloy comprises the following components in percentage by weight: Ni: 0.9wt%, P: 0.2%, impurities ≤ 0.4%, copper: balance, and the ratio of the mass percentage of Ni to P is 4.5; the casting temperature in the upward continuous casting is 1180° C., and the diameter of the casting rod is 25 mm;

[0063] (2) continuously extruding the copper alloy cast rod to prepare an extruded slab; the rotation speed of the extrusion wheel in the continuous extrusion slab is 3.5 r / min, and the preheating temperature of the extrusion die is 500° C.; in the step (2), the thickness of the extruded slab prepared after continuous extrusion is 12.6 mm;

[0064] (3) The extruded slab is subjected to a primary cold rolling, a two-stage aging heat treatment, and a secondary cold rolling process in sequence to obtain the Cu-Ni-P alloy strip; the total deformation in the primary cold rolling is 85%; in the two-stage aging process, the primary aging temperature is 280°C, the aging time is 3h, and the secondary aging is 400°C, and the aging time is 1.5h; the total deformation in the secondary cold rolling is 60%.

[0065] Comparative Example 4

[0066] Compared with Example 1, only the total deformation amount in the first cold rolling of step (3) is different, that is, the total deformation amount in the first cold rolling is 50%, and the other components, amounts and preparation methods are exactly the same.

[0067] Comparative Example 5

[0068] Compared with Example 1, only the total deformation amount in the secondary cold rolling in step (3) is different, and the total deformation amount in the secondary cold rolling is 20%. The other components, amounts and preparation methods are exactly the same.

[0069] Comparative Example 6

[0070] Compared with Example 1, only the total deformation amount in the secondary cold rolling in step (3) is different, and the total deformation amount in the secondary cold rolling is 80%. The other components, amounts and preparation methods are exactly the same.

[0071] Comparative Example 7

[0072] The Cu-Ni-P alloy strip was prepared by using the conventional process of semi-continuous casting-hot rolling-milling-cold rolling-air cushion furnace annealing-small deformation rolling-single-stage aging-cold rolling. The raw materials are exactly the same as those in Example 1. Specifically, the preparation method is as follows:

[0073] (1) A copper alloy is used as a raw material and a copper alloy ingot is prepared by a semi-continuous casting process; the copper alloy comprises the following components in percentage by weight: Ni: 0.9wt%, P: 0.2%, impurities ≤ 0.4%, copper: balance, and the ratio of the percentage by weight of Ni to P is 4.5;

[0074] (2) The ingot is hot rolled at a rolling temperature of 900°C and a final rolling temperature of 750°C. The hot rolled ingot is milled and then cold rolled to a thickness of 0.8 mm; the cold rolled strip is sent to an air cushion furnace for annealing at a temperature of 800°C and a copper strip running speed of 25 m / min; after annealing, the strip is rolled to 0.4 mm and subjected to aging heat treatment at a temperature of 450°C and an aging time of 4 h; after aging, the strip is rolled to 0.2 mm.

[0075] Performance Testing

[0076] The Cu-Ni-P alloy strips prepared in the embodiments of the present invention and the comparative examples were subjected to relevant performance tests, as follows:

[0077] Tensile strength: tested in accordance with GB / T228.1-2021;

[0078] Vickers hardness: tested in accordance with GB / T4320.1-2024;

[0079] Conductivity: Tested in accordance with GB / T351-2019;

[0080] Bending performance: According to GB / T15825.5 test, the rolling direction is defined as good way, and the transverse direction is defined as bad way.

[0081] The performance test results are shown in Table 1, where in Examples 1-11 and Comparative Examples 1-6, thickness 1 is the thickness of the extruded slab prepared after continuous extrusion, and in Comparative Example 7, thickness 1 is the thickness of the hot-rolled slab. Thickness 2 is the thickness of the Cu-Ni-P alloy strip finally obtained.

[0082] Table 1

[0083]

[0084]

[0085] As can be seen from the above table, the manufacturing method of the Cu-Ni-P alloy strip provided in the embodiment of the present invention adopts the process of upward continuous casting → homogenization heat treatment → continuous extrusion of slab → primary cold rolling → two-stage aging heat treatment → secondary cold rolling, and the alloy finally prepared has excellent strength and electrical conductivity at the same time, which meets the current requirements for high strength and high conductivity of alloys. The Cu-Ni-P alloy strip prepared by the manufacturing method of the Cu-Ni-P alloy strip provided in the embodiment of the present invention simultaneously meets the tensile strength of more than 600MPa and the electrical conductivity of more than 60%IACS, which meets the current requirements for high strength and high conductivity of alloys.

[0086] From Example 1 and Comparative Examples 1-2, it can be seen that when the mass percentage ratio of Ni and P in the copper alloy raw material is 3.0-5.5, the requirements of high strength and high conductivity can be met at the same time. When the mass percentage ratio of Ni and P is too small or too large, the tensile strength and conductivity are significantly reduced.

[0087] From the comparison between Example 1 and Comparative Example 3, it can be seen that the copper alloy casting rod prepared by the upward continuous casting process is subjected to homogenization heat treatment to eliminate grain boundary segregation, fully dissolve the Ni-P crystalline phase, and then undergo a subsequent continuous extrusion process, which can improve the tensile strength and electrical conductivity of the alloy strip. Comparative Example 3 does not use homogenization heat treatment, resulting in a significant decrease in tensile strength and electrical conductivity, and cannot simultaneously meet the requirements of high strength and high conductivity. Figure 1are microscopic morphology images of Cu-Ni-P alloy strips; wherein (a) is a microscopic morphology image of the Cu-Ni-P alloy strip prepared in Comparative Example 3, and (b) is a microscopic morphology image of the Cu-Ni-P alloy strip prepared in Example 1.

[0088] From the comparison between Example 1 and Comparative Examples 4-6, it can be seen that the different deformation amounts during the cold rolling process will lead to a decrease in the tensile strength or electrical conductivity of the final alloy strip, and the requirements of high strength and high conductivity cannot be met at the same time.

[0089] Comparative Example 7 is a traditional process. Compared with the traditional process, the present application greatly simplifies the process flow, shortens the process flow, and reduces the production cost. Figure 2 TEM images of Cu-Ni-P alloy strips; wherein (a) is the TEM image of the Cu-Ni-P alloy strip prepared in Comparative Example 7, and (b) is the TEM image of the Cu-Ni-P alloy strip prepared in Example 1.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for manufacturing a Cu-Ni-P alloy strip, characterized in that: The following steps are involved: Upward continuous casting → homogenization heat treatment → continuous slab extrusion → primary cold rolling → two-stage aging heat treatment → secondary cold rolling; (1) Using a copper alloy as a raw material, a copper alloy casting rod is prepared by an upward continuous casting process; the copper alloy comprises the following components in percentage by weight: Ni: 0.3-1.3wt%, P: 0.05-0.3%, impurities ≤ 0.4%, copper: balance, and the mass percentage ratio of Ni to P is 3.0-5.5; (2) subjecting the copper alloy cast rod to homogenization heat treatment and continuous extrusion to prepare an extruded slab; (3) The extruded slab is subjected to a primary cold rolling, a two-stage aging heat treatment, and a secondary cold rolling process in sequence to obtain the Cu-Ni-P alloy strip; the total deformation in the primary cold rolling is 70-95%; in the two-stage aging process, the primary aging temperature is 200-300°C, the aging time is 3-6h, and the secondary aging is 300-500°C, and the aging time is 1-4h; the total deformation in the secondary cold rolling is 40-70%.

2. The method for producing a Cu-Ni-P alloy strip according to claim 1, wherein: In the step (1), the casting temperature in the upward continuous casting is 1160-1200° C., and the diameter of the cast rod is 25-30 mm.

3. The method for producing a Cu-Ni-P alloy strip according to claim 1, wherein: In the step (2), the heat treatment temperature in the homogenization heat treatment is 850-900°C, and the heat treatment time is 3-5h; the extrusion wheel speed in the continuous extrusion slab is 3-5r / min, and the extrusion die preheating temperature is 450-650°C.

4. The method for producing a Cu-Ni-P alloy strip according to claim 1, wherein: In the step (2), the thickness of the extruded slab prepared after continuous extrusion is 12-14 mm.

5. The method for producing a Cu-Ni-P alloy strip according to claim 1, wherein: In the step (3), the thickness of the Cu-Ni-P alloy strip obtained by sequentially performing a first cold rolling, a two-stage aging heat treatment, and a second cold rolling process is 0.2-1.5 mm.

6. A Cu-Ni-P alloy strip manufactured by the method for manufacturing a Cu-Ni-P alloy strip as claimed in any one of claims 1 to 5.

7. Application of the Cu-Ni-P alloy strip as claimed in claim 6 in the fields of integrated circuits, rail transportation, aerospace, and communications.

8. The use according to claim 7, characterized in that The applications include applications in lead frames, automotive connectors, and vapor chambers.

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