CN1389597A - High-strength and high-conductivity nanometer crystal copper material and its prepn. - Google Patents

Abstract

A high-strength and high-conductivity nanocrystalline copper material with a density of 8.91±0.03g/cm ³ , a purity of 99.995±0.003wt%, a grain size of 5-80nm, a conductivity g of 80-99%LACS, and a fracture strength of 200~600MPa, the orientation difference between grains is 1~35°, and the deformation is 0~5100%; its preparation method: 1) prepare three-dimensional block nanocrystalline copper material by electrolytic deposition technology; 2) prepare high strength and high Conductive nano-crystalline copper material: cold-roll the above-mentioned electrodeposited nano-metal copper material at room temperature, with a deformation rate of 1×10 ⁻³ to 1×10 ⁻² /s. It has high strength and high conductivity.

Description

A kind of high-strength and high-conductivity nanocrystalline copper material and its preparation method

The invention relates to a nanocrystalline metal material, in particular to a high-strength and high-conductivity nanocrystalline copper material and a preparation method thereof.

Copper and its alloys are the earliest and most widely used non-ferrous metals. my country is one of the earliest countries to use copper alloys. Bronze was used to make bells, tripods and weapons as far back as the Yin and Zhou Dynasties more than 3,700 years ago. Until now, copper and its alloys are still the most widely used metal materials. The main characteristics of copper and its alloys are electrical conductivity and good thermal conductivity (the electrical conductivity and thermal conductivity of pure copper are second only to silver (Ag) among all metal materials), and they are resistant to air, seawater and many media. It has good corrosion resistance, good plasticity and wear resistance, and is suitable for various products produced by various plastic processing and casting methods. Missing metal material.

For pure copper, it has high deformability and low strength. Therefore, in order to improve the performance of copper materials, it is often necessary to add some less harmful alloying elements (such as Al, Fe, Ni, Sn, Cd, Zn, Ag, Sb, etc.) to improve its strength and hardness. However, the addition of these alloying elements tends to greatly reduce the conductivity of copper; in addition, a small amount of Fe and Ni have an impact on the magnetic properties of Cu, which is not good for the manufacture of compass and aviation instruments; Cd, Zn, Sn, Pb, etc. It is volatile in vacuum and is limited in the manufacture of electronic tube parts.

In today's modern scientific field, mechanical equipment, tools and instruments are all developing towards high speed, high efficiency, high sensitivity, low energy consumption, and miniaturization. Both put forward higher comprehensive requirements for copper materials. For example, in the rapidly developing computer industry, the automotive industry, the wireless communication industry (such as plug connectors for mobile phones and lithium battery anodes, etc.), the printing industry (such as multilayer printed circuit boards and high-density printed circuit boards) Manufacturing, etc.) and other high-tech products, the demand for new high-performance copper materials is also increasing, and copper materials are often required to have high strength, high thermal stability and high wear resistance while having high conductivity. sex.

Nanocrystalline materials refer to a class of single-phase or multi-phase solid materials composed of extremely fine grains with characteristic dimensions ranging from 1 to 100 nanometers. Due to its extremely fine grains, large interface density and a large number of defective atoms in grain boundaries and grains, nanomaterials show huge differences in physical and chemical properties from ordinary micron-scale polycrystalline materials, and have peculiar mechanics. Electrical, magnetic, optical, thermal and chemical properties. The grain size is an important factor affecting the mechanical properties of traditional metal polycrystalline materials (grain size is on the order of microns). As the grain size decreases, the strength and hardness of the material increase greatly. Early tests on the hardness of some nano-materials showed that the hardness of single nano-metal materials did increase (such as Fe, Cu, etc.) as the grain size decreased. At the same time, people have also found that due to the high volume percentage of grain boundaries in nanomaterials, the grain boundaries have a certain hindering effect on the conduction of electrons. Therefore, the conductivity of nanomaterials is smaller than that of ordinary coarse crystal materials, and the larger the grain size The smaller the value, the greater the drop in conductivity. Recent research results show that both the hardness/strength and electrical conductivity of nanomaterials are closely related to the structural characteristics of the material itself (such as interface structure, microscopic strain), stress state, and material density. Materials with the same composition obtained by different preparation and processing methods can exhibit completely different mechanical and electrical properties even if the grain size is the same. Accordingly, it can be predicted that if the grain size of a certain material is reduced to the nanometer level, and its microstructure can be controlled, it is possible to obtain the "ideal" of new high-tech performances with both high strength and high conductivity. Material.

Russian scientist R.Z.Valiev obtained submicron pure copper material by severe plastic deformation method. The severe plastic deformation method is to cause severe plastic deformation of the material through severe plastic deformation, resulting in a series of processes such as dislocation proliferation, movement, rearrangement, etc., so that the grains in the material are continuously refined to the submicron or even nanometer level, and The sample does not contain hole defects, and the grain boundary is clean. The disadvantage is that there is a large residual stress in the sample, and the resistance at room temperature is large.

At present, the high-quality copper films used in domestic production of lithium batteries for mobile phones (usually requiring high strength and low resistance) are generally imported copper foils, which are deposited and rolled. The thickness of this copper foil is about 15-20 μm. Among them, the room temperature tensile strength of rolled copper foil is 175MPa, the elongation is about 1%, and the room temperature resistivity is ρ=2.05×10 ^-8 Ωm (equivalent to conductivity g=82% IACS, where IACS is International annealed copper standard abbreviation). The room temperature fracture strength of the as-deposited copper foil is 120 MPa, the elongation is about 5%, and the room temperature resistivity is ρ=1.96×10 ^-8 Ωm (equivalent to conductivity g=86% IACS).

The purpose of the present invention is to provide a nanocrystalline copper material with high strength and high conductivity and a preparation method.

In order to achieve the above object, technical scheme of the present invention is:

A high-strength and high-conductivity nanocrystalline copper material has the following properties: a density of 8.91±0.03g/cm ³ , a purity of 99.995±0.003wt%, a grain size of 5-80nm, and an electrical conductivity g of 80-99% IACS, the fracture strength is 200-600MPa, the orientation difference between grains is 1-35°, and the deformation is 0-5100%;

The preparation method of the high-strength and high-conductivity nanocrystalline copper material is carried out in two steps:

1) Preparation of three-dimensional block nanocrystalline copper materials by electrolytic deposition technology: Electron-grade high-purity copper sulfate CuSO ₄ solution is used as the electrolyte, and high-purity ion-exchanged water or high-purity distilled water is added, and the acidity is 0.7-1.2mol/l; 1. Anode: The anode is a pure copper plate with a purity higher than 99.99%, and the cathode is a strictly polished titanium plate; additive components: 5-25% gelatin aqueous solution 0.02-0.15ml/l, 5-25% high-purity NaCl aqueous solution 0.2～1.0ml/l; electrolysis process parameters: current density 5.50～60mA/cm ² , cell voltage 0.2～1.0V, cathode and anode distance 30～300mm, electrolysis temperature 15～30℃;

2) Preparation of high-strength and high-conductivity nanocrystalline copper material: cold-roll the above electrolytically deposited nano-metallic copper material at room temperature, with a deformation rate of 1×10 ^-3 to 1×10 ^-2 /s, and a purity of 99.995± 0.003wt%, density of 8.91±0.03g/cm ³ , conductivity g of 80-99% IACS, fracture strength of 200-600MPa, misorientation between grains of 1-35°, deformation of 0-5100% copper material.

The present invention has the following advantages:

1. It has high strength and high conductivity. The method of the present invention utilizes reasonable process and process parameters in the electrolytic deposition technology to prepare block nanocrystalline Cu materials with high purity, high density and low microscopic strain (grain size is 30nm, 1nm= ^10-9 m), The fracture strength of the nanocrystalline Cu material at room temperature (only 0.22T _m , where T _m is the melting point of the material) is 210 MPa, and the resistivity is ρ=1.72*10 ^-8 Ωm (equivalent to conductivity g=99% IACS) ; The room temperature fracture strength of rolled nanocrystalline Cu foil will be greatly improved (up to 600MPa), but the room temperature resistance change is not very obvious, and it still has good conductivity (conductivity g=80～99%IACS) , the strength and conductivity values are greatly improved compared with the materials of the same composition currently on the market. In addition, when rolling deformation, the nano-Cu foil materials with different deformations, with the increase of deformation (0-1000%), the breaking strength of the material continuously increases from 200MPa to 500MPa, and the corresponding electrical conductivity decreases from g=99%IACS It is g=80% IACS. Continue to increase the amount of deformation, the strength and resistance of the material have no significant change.

2. High superplastic extensibility. The present invention utilizes electrolytic deposition technology to obtain a high-density block nanocrystalline Cu material at room temperature (only 0.22T _m , T _m is the melting point temperature of the material) with a fracture strength of 210MPa under reasonable process conditions. After rolling at room temperature A nanocrystalline Cu foil material with an elongation rate as high as 5000% is obtained, and its thickness can reach the limit thickness of the roll (as small as the order of microns).

3. Strong applicability. Because the present invention is rolling deformation, the nano-Cu foil material of different deformation, along with the increase of deformation (0～1000%), the breaking strength of material constantly increases from 200MPa to 500MPa, and corresponding electrical conductivity is from g=99% The IACS drops to g=80%IACS, and the deformation continues to increase, but the strength and electrical resistance of the material do not change significantly. Therefore, when the high-strength and high-conductivity nanocrystalline copper material obtained by the method of the present invention is actually used, the amount of deformation can be determined according to requirements to meet the requirements of high strength and high conductivity at the same time. This nanocrystalline Cu material with high strength and high conductivity is of great value to the rapidly developing computer industry, wireless communication industry and printing industry.

4. The preparation method is simple. Adopting the method of the invention, rolling at room temperature has no work hardening effect and no annealing process.

Figure 1 is the true stress-true strain curve of electrodeposited nanocrystalline Cu stretched at room temperature.

Fig. 2 is the true stress-true strain curve (room temperature) of electrodeposited nanocrystalline Cu at different stretching rates.

Fig. 3 is a macroscopic photo of rolled nanocrystalline Cu samples with different deformations at room temperature.

Fig. 4 is the tensile stress-strain curve at room temperature of electrodeposited nanocrystalline Cu and as-rolled nanocrystalline Cu foil (deformation amount is 1400%).

Fig. 5 is the resistivity curve of electrodeposited nano-crystal Cu and rolled nano-crystal Cu with different deformations as a function of temperature.

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Example 1

1. Preparation of three-dimensional bulk nanocrystalline Cu materials by electrolytic deposition technology:

Electrolytic deposition equipment: double pulse electrolytic deposition equipment

Requirements for the electrolyte used in electrolytic deposition: electronically pure grade CuSO ₄ solution, strictly control the content of heavy metal impurities in the electrolyte, the water used for distributing the electrolyte should be high-purity ion-exchanged water or high-purity distilled water, and the acidity of the electrolyte is: 1.0mol/ l.

Cathode and anode requirements: the anode is a pure copper plate with a purity higher than 99.99%, and the cathode is a pure titanium plate that has been strictly ground and polished.

Additive ingredients: gelatin: 0.1ml/l (15% gelatin aqueous solution)

     High-purity NaCl: 0.6ml/l (15% NaCl aqueous solution)

Electrolysis process parameters: current density: 30mA/cm ²

Slot voltage: 0.6V

Cathode, anode distance: 150mm

  Electrolysis temperature: 20°C

A bulk nanocrystalline Cu material with high purity, high density, _and low microscopic strain (grain size is 30nm, 1nm=10 ^-9 m) is prepared, and the nanocrystalline Cu material is at room temperature (only 0.22T _m is the melting point temperature of the material), the breaking strength is 210 MPa, and the resistivity is ρ=1.72*10 ^-8 Ωm (corresponding to the electrical conductivity g=99% IACS).

The results of chemical analysis showed that the purity of the deposited nano-Cu sample was 99.995wt%. The chemical composition content of trace impurities is shown in the table below:

Element Trace Content (%) Element Trace Content (%)

Bi ＜0.0001 Sn ＜0.0001

Sb 0.0001 Ag 0.0001

As 0.0001 Co 0.0001

Pb 0.0001 Zn 0.0002

Fe 0.0004 Ni 0.0002

Using LECO TC-436 oxygen/nitrogen analyzer to measure, the oxygen content in the sample is 24±1ppm. The sample density measured by Archimedes principle is 8.91±0.03g/cm ³ , which is equivalent to 99.4% of the theoretical density (8.96g/cm ³ ) of polycrystalline pure Cu. The results of positron annihilation spectroscopy experiments show that the sample contains neither vacancy-sized defects nor large pores, which further proves the high density of nanocrystalline Cu samples. X-ray diffraction results show that the average grain size of electrodeposited nanocrystalline Cu is about 30nm, and the microscopic strain in the sample is very small, only 0.03%. High-resolution electron microscopy observed that the grain size of nanocrystalline Cu was distributed between several nanometers and 80 nanometers, and the average grain size was 20nm. At the same time, it is also found that the grain orientation difference between most nanocrystalline particles belongs to the small-angle grain boundary, generally between 1° and 10°, and the dislocation density in the sample is also very small.

Room temperature stretching of electrolytically deposited nanocrystalline copper: Figure 1 shows the true stress-strain curve of electrolytically deposited nanocrystalline Cu samples at room temperature. It can be seen from the figure that when the stretching rate is 1×10 ^-4 s ^-1 , the yield strength σ _0.2 of electrolytically deposited nanocrystalline Cu = 119±5MPa, and the breaking strength _σb = 202±8MPa. More importantly, the electrolytically deposited nanocrystalline Cu sample has good plasticity, and the elongation can reach 30%.

Room temperature stretching of electrolytically deposited nanocrystalline Cu samples at different stretching rates: Figure 2 shows the electrolytically deposited nanocrystalline Cu samples at room temperature at different stretching rates (6×10 ^-5 ～1.8×10 ³ s ^-1 ) True stress-strain curves for tensile experiments. It can be seen that the strength and plasticity of electrodeposited nanocrystalline Cu have a clear trend of change with different stretching rates: when the stretching rate increases from 6×10 ^-5 s ^-1 to 1.8×10 ³ s ^-1 , the The yield strength increased from 72MPa to 122MPa, and its fracture strength increased from 156MPa to 292MPa. At the same time, the true strain of the material also increased from 15% to 33% (this is whether the tensile strength or the true strain increases with the tensile rate. The phenomenon of the increase of the increase is completely different from the change trend of the ordinary coarse crystal Cu material with the stretching rate). In the higher dynamic impact tensile test (stretching rate of 1.8×10 ³ s ^-1 ), the fracture strength of electrodeposited nanocrystalline Cu can be as high as 600MPa, and the elongation can be as high as 55%.

2. Obtain high-strength, high-conductivity nanobody Cu material (Cu wire or Cu foil) by rolling at room temperature:

The electrodeposited nano-metallic Cu material is cold-rolled at room temperature using a two-roller roll equipment, wherein the amount of deformation ε is calculated by the following formula: ε=(δ ₀ -δ)/δ, wherein δ ₀ and δ represent the samples respectively The original thickness and the thickness at the completion of rolling, the deformation rate is 1×10 ^-2 /s.

A section of electrolytically deposited nanocrystalline Cu sample with a size of 16mm×4mm×1mm and a grain size of 30nm was cold-rolled at room temperature. change (<5%). After continuous rolling, the sample becomes longer and longer, and finally the nanocrystalline Cu sample becomes a film strip with a smooth surface and no cracks around it. At this time, the total deformation is about 5100%, as shown in Figure 3. At the end of rolling The thickness of the Cu film sample is about 20 μm (this is the limit thickness of this rolling mill), and further rolling can still be carried out. A copper material with a purity of 99.995wt%, a density of 8.91g/cm ³ , an electrical conductivity g of 80% IACS, a fracture strength of 500MPa, an orientation difference of 10-35° between crystal grains and a deformation of 700% was obtained.

X-ray diffraction results show that the average grain size of nanocrystalline Cu in the as-rolled state is still 30nm, and the microscopic strain in the sample increases to 0.16%. High-resolution electron microscope observation of the microstructure of nanocrystalline Cu samples after cold rolling proved that the grain size in the nanocrystalline Cu samples did not change during the rolling process, but in the as-rolled nanocrystalline Cu samples, the dislocation density (mainly concentrated at the grain boundary) increased significantly, and the orientation difference between the grains also increased significantly. The statistical results show that the orientation difference between the grains in the nanocrystalline Cu sample after full rolling is about 10~ 35°, significantly higher than the misorientation of grains in the electrodeposited bulk nanocrystalline Cu samples.

Using electrolytic deposition technology, high-density bulk nanocrystalline Cu materials were obtained under reasonable process conditions. The material has no work hardening effect when rolled at room temperature, and nanocrystalline Cu foil material with an elongation rate of up to 5000% can be obtained at room temperature without an annealing process, and its thickness can reach the limit thickness of the roll (as small as microns), The grain size in the nanocrystalline Cu film remained unchanged during the rolling process, and there was no obvious work hardening effect in the material. The room temperature fracture strength of rolled nanocrystalline Cu foil will be greatly improved (up to 600MPa), but the room temperature resistance change is not very obvious, and it still has good conductivity (conductivity g=80%IACS), this strength Compared with the materials of the same composition currently on the market, both the conductivity and conductivity values have been greatly improved.

Example 2

The difference from Example 1 is:

1) Preparation of three-dimensional block nanocrystalline copper materials by electrolytic deposition technology: Electron-grade high-purity copper sulfate CuSO ₄ solution is used as electrolyte, and high-purity ion-exchanged water or high-purity distilled water is added, with an acidity of 0.7mol/l; cathode and anode : The anode is a pure copper plate with a purity higher than 99.99%, and the cathode is a titanium plate that has been strictly polished and polished; additive ingredients: 5% concentration of gelatin aqueous solution 0.02ml/l, 5% concentration of high-purity NaCl aqueous solution 0.2ml/l; electrolysis Process parameters: current density is 5.5mA/cm ² , cell voltage is 0.2V, distance between cathode and anode is 30mm, electrolysis temperature is 15℃;

2) Preparation of high-strength and high-conductivity nanocrystalline copper material: cold-roll the above electrolytically deposited nano-metallic copper material at room temperature with a deformation rate of 1×10 ^-3 /s to obtain a purity of 99.992wt% and a density of 8.88g /cm ³ , the electrical conductivity g is 80% IACS, the fracture strength is 400MPa, the misorientation between grains is 8-30°, and the deformation is 1400%.

Comparison of tensile properties of as-rolled nanocrystalline Cu and electrodeposited nanocrystalline Cu: The electrodeposited nanocrystalline Cu sample and the as-rolled nanocrystalline Cu sample with a deformation of 1400% were stretched at the same tensile rate at room temperature , the results are not the same, as shown in Figure 4, the tensile strength of the rolled nanocrystalline Cu foil is greatly improved compared with the deposited state, and its yield stress is nearly three times higher than that of the deposited state, from 94MPa to 380MPa , the fracture stress also doubled, up to 400MPa. However, it can also be clearly seen from the figure that the elongation of the rolled nanocrystalline Cu foil is only 1.7%, which is about an order of magnitude smaller than that of the deposited nanocrystalline Cu foil.

Comparison of the low-temperature resistance properties of rolled nanocrystalline Cu and electrodeposited nanocrystalline Cu: Figure 5 shows the resistivity curves of nanocrystalline Cu materials with different deformations as a function of temperature. It is obvious that at a given temperature, the greater the amount of deformation, the greater the resistivity of nanocrystalline Cu. For example, at 273K, the resistivity of electrodeposited nanocrystalline Cu (ε=0%) is ρ=1.65×10 ^-8 Ωm, and the resistivity of ε=450% rolled nanocrystalline Cu foil is ρ=1.78×10 ^{- 8} Ωm, ε=800% as-rolled nanocrystalline Cu foil has a resistivity ρ=2.09×10 ^-8 Ωm, and when the deformation exceeds 1000%, with the increase of deformation, the resistivity of the as-rolled nanocrystalline Cu foil The resistivity does not continue to increase, but basically maintains a constant value, about 2.1×10 ^-8 Ωm.

Example 3

The difference from Example 1 is:

1) Preparation of three-dimensional block nanocrystalline copper material by electrolytic deposition technology: Electron-grade high-strength copper sulfate CuSO ₄ solution is used as electrolyte, and high-purity ion-exchanged water or high-purity distilled water is added, with an acidity of 1.2mol/l; cathode and anode : The anode is a pure copper plate with a purity higher than 99.99%, and the cathode is a strictly ground and polished titanium plate; additive components: 25% gelatin aqueous solution 0.15ml/l, 25% high-purity NaCl aqueous solution 1.0ml/l; electrolysis Process parameters: the current density is 60mA/cm ² , the cell voltage is 1.0V, the distance between cathode and anode is 300mm, and the electrolysis temperature is 30°C;

2) Preparation of high-strength and high-conductivity nanocrystalline copper material: cold-roll the above-mentioned electrolytically deposited nano-metallic copper material at room temperature with a deformation rate of 1×10 ^-2 /s to obtain a purity of 99.998wt% and a density of 8.94g /cm ³ , the electrical conductivity g is 90% IACS, the fracture strength is 350MPa, the misorientation between grains is 5-20°, and the deformation is 700%.

Comparative Example 1: Coarse crystalline pure copper (grain size about 100 μm) in ordinary annealed state is stretched at room temperature, its fracture ultimate strength σ _uts ≤ 200 MPa, yield strength σ _y ≤ 35 MPa, and elongation δ ≤ 60%. The fracture strength and yield strength of ordinary coarse crystal pure copper after cold rolling can be increased to 290MPa and 250MPa respectively, and its elongation is about 8%. Therefore, for ordinary coarse crystal pure copper (whether it is annealed or cold-rolled), its ultimate fracture strength is often less than 300MPa.

Comparative Example 2: Under the same conditions, it was found that an ordinary coarse-grained pure Cu sample was cold-rolled, and when the deformation amount was about 800%, obvious cracks had already occurred. The 30nm nanocrystalline Cu sample was annealed at 500°C for 48 hours under vacuum conditions to make the grain grow sufficiently (grain size greater than 100 μm). The annealed Cu sample was cold-rolled under the same conditions, and it was also found that when the deformation was about 700%, there were obvious cracks around the sample. The influence of purity on room temperature plasticity of samples can be ruled out through the above experimental comparison. This shows that only nanocrystalline materials can achieve superplastic ductility at room temperature.

Comparative Example 3: American scientists J.Weertman et al. (PGSanders, JAEastman and JRWeertman, in Processing and Properties of Nanocrystalline Materials, C.Suryanarayana, J.Singh and FHFroes, Eds. (TMS, 1996), p379) utilize inert gas condensation Method and high vacuum (10 ^-5 ~ 10 ^-6 Pa) in-situ pressurization technology (pressure is usually 1 ~ 5GPa), prepared solid nanocrystalline copper material with an average grain size of 22 ~ 110nm, the density of the sample is about 96% of the theoretical density, and the microscopic strain in the sample is relatively large. The results of the static tensile test at room temperature show that the strength of the nanocrystalline copper material is greatly improved compared with that of the common coarse crystalline copper material, and its fracture strength can be as high as 415MPa-480MPa. The fracture strength of the sample is related to the preparation process of the sample and the average grain size (for example, the finer the grain size, the higher the strength, the coarser the grain size, the lower the strength), and the plasticity increases with the decrease of the grain size. Small and reduced. The phenomenon of high strength and low plasticity of nanocrystalline copper prepared by ultrafine powder cold pressing synthesis is related to a large number of defects introduced in the sample preparation process (such as holes, pollution, incomplete grain boundaries and large residual internal stress, etc.).

Comparative example 4: Russian scientist RZValiev (RKIslamgaliev, P.Pekala, M.Pekalaand REValiev, Plys.Stat.Sol.(a) 162 , 559(1997)) obtained submicron pure copper material by severe plastic deformation method, Its average grain size is 210nm, and the sample has good compactness, but the residue is large. Stretched at room temperature, its ultimate breaking strength can reach 500MPa, and the elongation is about 5%. This material has a relatively high resistance at room temperature, and the resistivity is ρ=2.24×10 ^-8 Ωm (equivalent to conductivity g=70 %IACS).

Claims (2)

1. A high-strength and high-conductivity nanocrystalline copper material, characterized in that it has the following properties: a density of 8.91±0.03g/cm ³ , a material purity of 99.995±0.003wt%, a grain size of 5-80nm, and an electrical conductivity of g Up to 80-99% IACS, fracture strength up to 200-600MPa, orientation difference between crystal grains is 1-35°, and deformation is 0-5100%. 2. a kind of preparation method according to the described high-intensity high-conductivity nano-crystal copper material of claim 1, is characterized in that: 1) Preparation of three-dimensional block nanocrystalline copper materials by electrolytic deposition technology: Electron-grade high-purity copper sulfate CuSO ₄ solution is used as the electrolyte, and high-purity ion-exchanged water or high-purity distilled water is added, and the acidity is 0.7-1.2mol/l; 1. Anode: The anode is a pure copper plate with a purity higher than 99.99%, and the cathode is a strictly polished titanium plate; additive components: 5-25% gelatin aqueous solution 0.02-0.15ml/l, 5-25% high-purity NaCl aqueous solution 0.2～1.0ml/l; electrolysis process parameters: current density 5.5～60mA/cm ² , cell voltage 0.2～1.0V, cathode and anode distance 30～300mm, electrolysis temperature 15～30℃; 2) Preparation of high-strength and high-conductivity nanocrystalline copper material: cold-roll the above electrolytically deposited nano-metallic copper material at room temperature, with a deformation rate of 1×10 ^-3 to 1×10 ^-2 /s, and a purity of 99.995± 0.003wt%, density of 8.91±0.03g/cm ³ , conductivity g of 80-99% IACS, fracture strength of 200-600MPa, misorientation between grains of 1-35°, deformation of 0-5100% copper material.

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