High-temperature-resistant fine-grain high-conductivity copper material and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant fine-grain high-conductivity copper material, which belongs to the technical field of high-performance copper materials for electronic communication and comprises the following raw materials in percentage by mass: 8 to 50 ppm of iron, 15 to 20 ppm of sulfur, 10 to 15 ppm of manganese, 20 to 25 ppm of titanium, 10 to 20 ppm of aluminum, 5 to 10 ppm of chromium and the balance of copper and inevitable impurities. The invention further discloses a preparation method of the high-temperature-resistant fine-grain high-conductivity copper material. Nitrogen is introduced in the smelting process, a proper hot rolling structure is obtained by controlling the hot rolling deformation amount and the finish rolling temperature, grains with the small size can be obtained at the high temperature by combining the copper material prepared through the set cold rolling and annealing technology, and the conductivity and the high-temperature structure stability are well considered. According to the high-temperature-resistant fine-grain high-conductivity copper material, the conductivity is 100% IACS or above, and the average grain size is smaller than 150 micrometers after heat preservation treatment is conducted for 10 min at the temperature of 1065 DEG C.

Description

Technical Field

[0001] The invention belongs to the technical field of high-performance copper materials for electronic communications, and in particular relates to a high-temperature resistant fine-grained high-conductivity copper material and a preparation method thereof. Background Art

[0002] With the development of the electronics industry, highly conductive, high-temperature, fine-grained copper strips / foils have been widely used in electronic components for new energy vehicles and high-speed railways.

[0003] Pure copper can be well applied in new energy vehicles and high-speed rail due to its excellent electrical and thermal conductivity, but its grain growth at high temperature will cause parts to fail and create safety hazards during vehicle driving.

[0004] Generally, adding alloying elements can inhibit the growth of grains at high temperatures, but alloying elements have a great influence on the electrical conductivity of pure copper. As the content of alloying elements increases, the electrical conductivity of copper will decrease, making it difficult to strike a good balance between electrical conductivity and grain size at high temperatures. How to obtain highly conductive, high-temperature resistant fine-grained copper materials is an important research direction for high-performance copper materials. Summary of the invention

[0005] In view of one or more of the above defects or improvement needs of the prior art, the present invention provides a high-temperature resistant fine-grained high-conductivity copper material and a preparation method thereof, which can take into account both the conductivity and high-temperature structural stability of copper.

[0006] To achieve the above object, according to one aspect of the present invention, a high temperature resistant fine-grained high-conductivity copper material is provided, which comprises the following raw materials by mass fraction: Iron: 8~50ppm, sulfur: 15~20ppm, manganese: 10~15ppm, titanium: 20~25ppm, aluminum: 10~20ppm, chromium: 5~10ppm, the balance is copper and unavoidable impurities.

[0007] As a further improvement of the present invention, the total content of the impurities is lower than 15 ppm.

[0008] As a further improvement of the present invention, the electrical conductivity of the copper material is above 100% IACS, and after being treated at 1065° C. for 10 minutes, the average grain size of the copper material is less than 150 μm.

[0009] According to another aspect of the present invention, a method for preparing a high temperature resistant fine-grained high-conductivity copper material is provided, which is used to prepare the high temperature resistant fine-grained high-conductivity copper material, comprising the following steps: (1) Preparation of ingots: Weighing the raw materials and adding them into a furnace for smelting to obtain an ingot; (2) hot rolling: hot rolling the ingot to obtain a hot-rolled plate; The hot rolling process is as follows: the starting rolling temperature is 700°C to 750°C, the first pass deformation is 30% to 50%, the total rolling deformation is 80% to 90%, and the final rolling temperature is 400°C to 500°C; (3) Cold rolling and annealing: The hot rolled sheet is cold rolled with a deformation amount of 50% to 55%, and then subjected to a first annealing; then cold rolled with a deformation amount of 70% to 73%, and then subjected to a second annealing; then cold rolled with a deformation amount of 80% to 85%, and finally subjected to a third annealing.

[0010] The copper material described in the embodiments of the present invention includes but is not limited to copper strips, copper foils, etc.

[0011] As a further improvement of the present invention, in step (3), The first annealing process is: 300°C-350°C for 2-5 minutes; The second annealing process is: 300°C-350°C for 2-5 minutes; The third annealing process is: keeping at 300° C. for 1 to 2 minutes.

[0012] As a further improvement of the present invention, in step (1), During the smelting process, pure nitrogen with a purity of 99.99% or high-purity nitrogen with a purity of 99.999% is introduced.

[0013] It should be noted that, in the preparation method of the present invention, unless otherwise specified, the technical means used are conventional means well known to those skilled in the art. For example, in step (1), the smelting process for preparing the ingot is a conventional prior art; in step (3), how to achieve cold rolling with a deformation amount of 50% to 55%, cold rolling with a deformation amount of 70% to 73%, and cold rolling with a deformation amount of 80% to 85% are conventional means well known to those skilled in the art, as long as the deformation amount can be controlled within this range.

[0014] The introduction of nitrogen in the melting and casting of the present invention, combined with the set alloy elements, can form a variety of dispersed compounds, such as nitrogen-containing compounds, during the solidification process; the use of a lower hot rolling temperature can inhibit the second phase from melting back and coarsening; and after subsequent cold rolling deformation, strong work hardening and extremely high dislocation density can be produced. Finally, combined with an appropriate annealing process, fine grains are formed, which can effectively inhibit the growth of grains at high temperatures.

[0015] In general, the above technical solution conceived by the present invention has the following beneficial effects compared with the prior art: (1) In the present invention, nitrogen is introduced during the smelting process, and a suitable hot-rolled structure is obtained by controlling the hot-rolling deformation amount and the final rolling temperature. The copper material prepared by the set cold rolling and annealing process can obtain finer grains at high temperatures, better balance the electrical conductivity and high-temperature structure stability, and obtain a high-performance copper material.

[0016] (2) The present invention can avoid the addition of rare earth or precious metal elements by adding trace alloy elements in combination, which is low-cost. In addition, the added alloy elements are not easily burned and their content is easy to control.

[0017] (3) The preparation method of the present invention adopts a process that is easy to control, has low cost, and is suitable for industrial production.

[0018] (4) The high temperature resistant fine-grained high-conductivity copper material of the present invention has a conductivity of more than 100% IACS; after being treated at 1065° C. for 10 minutes, the average grain size is less than 150 μm. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a microstructure photograph of the copper material of Example 1 of the present invention after annealing at high temperature.

[0020] Figure 2 This is a microstructure photograph of the copper material of Example 2 of the present invention after annealing at high temperature.

[0021] Figure 3 This is a microstructure photograph of the copper material of Example 3 of the present invention after annealing at high temperature. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] In the specific embodiments of the present invention, unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the materials, reagents, etc. used are all commercially available.

[0024] Example 1 In this embodiment, the high temperature resistant fine-grained high-conductivity copper material has copper as the main element, and other elements are added in trace amounts. Specifically, by mass fraction, it includes the following raw materials: Iron: 8ppm, sulfur: 15ppm, manganese: 10ppm, titanium: 20ppm, aluminum: 10ppm, chromium: 5ppm, the balance is copper and inevitable impurities. The total content of inevitable impurities is less than 15ppm.

[0025] The preparation method of the high temperature resistant fine-grained high-conductivity copper material of this embodiment is as follows: (1) Weighing raw materials and adding them into a furnace for smelting to obtain an ingot; The smelting is carried out in a non-vacuum manner, and pure nitrogen with a purity of 99.99% is introduced into the melt; the copper ingot obtained by the smelting is used as the initial ingot.

[0026] (2) hot rolling: hot rolling the ingot in step (1) to obtain a hot-rolled plate; The specific hot rolling process is as follows: the starting rolling temperature is 700°C, the first deformation is 30%, the total rolling deformation is 80%, and the final rolling temperature is 500°C.

[0027] (3) Cold rolling and annealing: The hot-rolled sheet in step (2) is cold rolled with a deformation of 50%, and then kept at 300°C for 2 minutes; then cold rolled with a deformation of 70%, and then kept at 300°C for 2 minutes; then cold rolled with a deformation of 80%, and finally kept at 300°C for 1 minute.

[0028] The high temperature resistant fine grain high conductivity copper material prepared in this embodiment has a conductivity of 100% IACS. In addition, the metallographic photograph of the copper material prepared in this embodiment after being kept at 1065°C for 10 minutes is as follows: Figure 1 As shown, it can be seen that the grain size is relatively fine, and the average grain size is about 100 microns. The results show that the copper material of this embodiment can take into account both the electrical conductivity and high temperature structural stability of copper.

[0029] Example 2 In this embodiment, the high temperature resistant fine-grained high-conductivity copper material has copper as the main element, and other elements are added in trace amounts. Specifically, by mass fraction, it includes the following raw materials: Iron: 50ppm, sulfur: 20ppm, manganese: 15ppm, titanium: 25ppm, aluminum: 20ppm, chromium: 10ppm, the balance is copper and inevitable impurities. The total content of inevitable impurities is less than 15ppm.

[0030] The preparation method of the high temperature resistant fine-grained high-conductivity copper material of this embodiment is as follows: (1) Weighing raw materials and adding them into a furnace for smelting to obtain an ingot; The copper ingot obtained by smelting is used as the initial ingot.

[0031] (2) hot rolling: hot rolling the ingot in step (1) to obtain a hot-rolled plate; The specific hot rolling process is as follows: the starting rolling temperature is 750°C, the first pass deformation is 50%, the total rolling deformation is 90%, and the final rolling temperature is 400°C.

[0032] (3) Cold rolling and annealing: The hot-rolled plate in step (2) is cold rolled with a deformation of 53%, and then kept at 320°C for 5 minutes; then cold rolled with a deformation of 70%, and then kept at 320°C for 3 minutes; then cold rolled with a deformation of 83%, and finally kept at 300°C for 2 minutes.

[0033] The high temperature resistant fine grain high conductivity copper material prepared in this embodiment has a conductivity of 100% IACS. In addition, the metallographic photograph of the copper material prepared in this embodiment after being kept at 1065°C for 10 minutes is as follows: Figure 2 As shown, it can be seen that the grain size is relatively fine, and the average grain size is about 100 microns. The results show that the copper material of this embodiment can take into account both the electrical conductivity and high temperature structural stability of copper.

[0034] Example 3 In this embodiment, the high temperature resistant fine-grained high-conductivity copper material has copper as the main element, and other elements are added in trace amounts. Specifically, by mass fraction, it includes the following raw materials: Iron: 20ppm, sulfur: 17ppm, manganese: 12ppm, titanium: 22ppm, aluminum: 15ppm, chromium: 8ppm, the balance is copper and inevitable impurities. The total content of inevitable impurities is less than 15ppm.

[0035] The preparation method of the high temperature resistant fine-grained high-conductivity copper material of this embodiment is as follows: (1) Weighing raw materials and adding them into a furnace for smelting to obtain an ingot; The smelting is carried out in a non-vacuum manner, and pure nitrogen with a purity of 99.99% is introduced into the melt; the copper ingot obtained by the smelting is used as the initial ingot.

[0036] (2) hot rolling: hot rolling the ingot in step (1) to obtain a hot-rolled plate; The specific hot rolling process is as follows: the starting rolling temperature is 730°C, the first pass deformation is 40%, the total rolling deformation is 85%, and the final rolling temperature is 450°C.

[0037] (3) Cold rolling and annealing: The hot rolled sheet in step (2) is cold rolled with a deformation of 55%, and then kept at 300°C for 5 minutes; then cold rolled with a deformation of 70%, and then kept at 300°C for 5 minutes; then cold rolled with a deformation of 80%, and finally kept at 300°C for 2 minutes.

[0038] The high temperature resistant fine grain high conductivity copper material prepared in this embodiment has a conductivity of 100% IACS. In addition, the metallographic photograph of the copper material prepared in this embodiment after being kept at 1065°C for 10 minutes is as follows: Figure 3 As shown, it can be seen that the grain size is relatively fine, and the average grain size is about 100 microns. The results show that the copper material of this embodiment can take into account both the electrical conductivity and high temperature structural stability of copper.

[0039] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high temperature resistant fine-grained high-conductivity copper material, characterized in that: Calculated by mass fraction, including the following raw materials: Iron: 8~50ppm, sulfur: 15~20ppm, manganese: 10~15ppm, titanium: 20~25ppm, aluminum: 10~20ppm, chromium: 5~10ppm, the balance is copper and inevitable impurities.

2. The high temperature resistant fine-grained high-conductivity copper material according to claim 1, characterized in that: The total content of the impurities is less than 15 ppm.

3. The high temperature resistant fine-grained high-conductivity copper material according to claim 1 or 2, characterized in that: The electrical conductivity of the copper material is above 100% IACS, and after being treated at 1065° C. for 10 minutes, the average grain size of the copper material is less than 150 μm.

4. A method for preparing a high temperature resistant fine-grained high-conductivity copper material, used for preparing the high temperature resistant fine-grained high-conductivity copper material according to any one of claims 1 to 3, characterized in that: The steps include: (1) Preparation of ingots: Weighing the raw materials and adding them into a melting furnace for smelting to obtain an ingot; (2) hot rolling: hot rolling the ingot to obtain a hot-rolled plate; The hot rolling process is as follows: the starting rolling temperature is 700°C to 750°C, the first pass deformation is 30% to 50%, the total rolling deformation is 80% to 90%, and the final rolling temperature is 400°C to 500°C; (3) Cold rolling and annealing: The hot rolled sheet is cold rolled with a deformation amount of 50% to 55%, and then subjected to a first annealing; then cold rolled with a deformation amount of 70% to 73%, and then subjected to a second annealing; then cold rolled with a deformation amount of 80% to 85%, and finally subjected to a third annealing.

5. The method for preparing a high temperature resistant fine-grained high-conductivity copper material according to claim 4, characterized in that: In step (3), The first annealing process is: 300°C-350°C for 2-5 minutes; The second annealing process is: 300°C-350°C for 2-5 minutes; The third annealing process is: keeping at 300° C. for 1 to 2 minutes.

6. The method for preparing a high temperature resistant fine-grained high-conductivity copper material according to claim 4 or 5, characterized in that: In step (1), during the smelting process, pure nitrogen with a purity of 99.99% or high-purity nitrogen with a purity of 99.999% is introduced.

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