Composite wire-drawing aquadag applied to drawing of different metal microwires and preparation method of composite wire-drawing aquadag

Abstract

The invention provides composite wire drawing aquadag applied to drawing of different metal microwires and a preparation method of the composite wire drawing aquadag, and relates to the technical field of metal forming machining. The aquadag comprises the following components in percentage by mass: 15%-22% of modified graphite / modified graphene oxide, 3%-5% of a dispersing agent, 1%-5% of a thickening agent, 2%-8% of a binder, 3%-5% of an organic auxiliary agent, 2%-4% of ammonia water and the balance of water, wherein both the modified graphite and the modified graphene oxide are graphite and graphene oxide of which the surfaces are modified by oxygen-containing functional groups. Graphene oxide is introduced on the basis of traditional aquadag, oxygen-containing functional groups are further grafted on the surface of graphite / graphene oxide, the wettability and lubricating performance of the aquadag are remarkably improved, and the aquadag can adapt to the drawing process of various metal microwires.

Description

Technical Field

[0001] The present invention relates to the technical field of metal forming and processing, in particular to a composite drawing graphite emulsion used for drawing different metal microfilaments and a preparation method thereof. Background Art

[0002] With the continuous advancement of materials science, various ultrafine metal microwires below 30μm, due to their unique physical and chemical properties and excellent mechanical performance, have demonstrated irreplaceable and important roles in multiple high-tech fields, becoming one of the key foundational materials driving technological development and industrial innovation. Tungsten wire, with its excellent high-temperature strength and thermal stability, plays a vital role in photovoltaic silicon wafer cutting and electronic filament manufacturing. Molybdenum wire, with its excellent electrical conductivity, high-temperature resistance, and corrosion resistance, is widely used in electron beam evaporation and high-temperature heating elements. Titanium wire, with its excellent biocompatibility and mechanical properties, not only protects human health in the biomedical field, but also helps achieve high-performance and lightweight aircraft in the aerospace field.

[0003] In the drawing and forming process of the above-mentioned metal microwires, lubricant graphite emulsion is one of the key factors affecting product quality and processing efficiency. During the drawing process, a large friction force will be generated between the metal microwire and the drawing die hole. If the lubrication performance is insufficient, it is very easy to cause the microwire to break. Especially with the trend of further reduction in the diameter of the metal microwire, the wire breakage rate will increase significantly, seriously affecting production efficiency and product yield. In order to meet the development needs of continuously reducing wire diameters, it is urgent to develop graphite emulsions with better wettability and better lubrication effect to improve the lubrication performance during the drawing process of metal microwires below 30μm. The key to achieving this goal is that the graphite emulsion can form a dense and high-strength graphite film on the surface of the metal microwire, which is the key prerequisite for ensuring good lubricity. However, different types of metal microwires have different adhesion abilities to graphite emulsions, which affects the quality of graphite layer formation.

[0004] Therefore, it is necessary to explore a graphite emulsion suitable for different types of metal microwire drawing processes, so that it can be highly matched with the metal microwire drawing and can significantly improve the quality of the metal microwire during the drawing process, providing strong support for the ultra-fine processing of metal microwires. Summary of the Invention

[0005] In view of this, the present invention proposes a composite drawing graphite emulsion and a preparation method thereof for use in drawing different metal microwires. The emulsion can exhibit excellent lubrication properties in drawing fine wires below 30 μm, forming a dense and high-strength graphite lubrication layer on the surface of the metal microwires, so that the drawn metal microwires have higher surface quality and fewer defects and cracks.

[0006] In a first aspect, the present invention provides a composite drawing graphite emulsion for use in drawing different metal microfilaments, comprising the following components, calculated by mass percentage: 15% to 22% of modified graphite / modified graphene oxide, 3% to 5% of a dispersant, 1% to 5% of a thickener, 2% to 8% of a binder, 3% to 5% of an organic additive, 2% to 4% of aqueous ammonia, and the balance being water; The modified graphite / modified graphene oxide are both graphite and graphene oxide whose surfaces are modified with oxygen-containing functional groups.

[0007] Furthermore, the oxygen-containing functional group is selected from one or more of a carboxyl group, an epoxy group, and a sulfonic acid group.

[0008] Furthermore, the carboxyl group is obtained by oxidation reaction of graphite or graphene oxide with at least one of potassium permanganate, sodium nitrate, and concentrated sulfuric acid; the epoxy group comes from at least one of peracetic acid and sodium acetate; and the sulfonic acid group comes from at least one of chlorosulfonic acid and concentrated sulfuric acid.

[0009] Furthermore, the modified graphene oxide is 0.1 wt% to 2.0 wt% of the mass of the modified graphite.

[0010] Furthermore, the mass ratio of the total carbon element to the total oxygen element in the modified graphene oxide and the modified graphite is 1:(0.8-1.2).

[0011] Furthermore, the organic auxiliary agent is selected from one or more of ethylene glycol, polyvinyl alcohol, and ethylene glycol butyl ether.

[0012] Furthermore, the composite drawing graphite emulsion has a solid content of 21% to 35%, a pH of 9 to 11, and an ash content of no more than 1%.

[0013] In a second aspect, the present invention relates to a method for preparing the composite drawing graphite emulsion for drawing different metal microwires, comprising the following steps: S1. Surface modification of graphite and graphene oxide to obtain modified graphite and modified graphene oxide; S2. Prepare materials according to the mass percentage, add modified graphite, modified graphene oxide and dispersant into water, stir, add thickener, binder, organic additive and ammonia water, ball mill to obtain drawing graphite emulsion.

[0014] Furthermore, the modification process includes: Under stirring conditions, graphite and graphene oxide are dispersed in concentrated sulfuric acid with sodium nitrate respectively, followed by adding potassium permanganate, stirring is continued at 0-5°C for 2-4 hours, and then maintained at 20-28°C for 6-8 hours, filtered, washed, and dried to obtain graphite or graphene oxide with carboxyl groups grafted on the surface; Alternatively, graphite and graphene oxide are dispersed in peracetic acid and sodium acetate solutions respectively, stirred at 30-40° C. for 4-5 hours, and after the reaction is completed, filtered, washed, and dried to obtain graphite or graphene oxide with epoxy groups grafted on the surface; Alternatively, graphite and graphene oxide are placed in concentrated sulfuric acid and stirred for 10 to 20 minutes, followed by adding chlorosulfonic acid, and stirring is continued at 0 to 5°C for 2 to 4 hours, and then maintained at 20 to 28°C for 6 to 8 hours, filtered, washed, and dried to obtain graphite or graphene oxide with sulfonic acid groups grafted on the surface.

[0015] Furthermore, in step S2, the ball milling speed is 300-400 r / min, and the time is 8-12 h.

[0016] In a third aspect, the present invention provides a method for drawing metal microwires, using the composite drawing graphite emulsion used for drawing different metal microwires as a lubricant.

[0017] Furthermore, the method is applicable to the drawing of microwires of different metal materials within the diameter range of 25 to 30 μm, and the coil diameter of the metal microwire obtained after drawing is not less than 40 mm.

[0018] The composite drawing graphite emulsion for drawing different metal microfilaments and the preparation method thereof of the present invention have the following beneficial effects compared with the prior art: This invention introduces graphene oxide into traditional graphite emulsions. By grafting different oxygen-containing functional groups onto the graphite / graphene oxide surfaces, the wettability and lubricity of the graphite emulsion are significantly improved, making it suitable for the drawing process of various metal microwires. Compared with existing commercially available graphite emulsions, the graphite / graphene oxide composite drawing graphite emulsion prepared by this invention can be effectively applied to the drawing process of ultrafine metal microwires of 25–30 μm. Furthermore, the grafted modified graphite / graphene oxide can form a denser and more strongly adherent graphite layer on the surface of the metal microwires, significantly reducing frictional resistance and wire breakage during the drawing process, improving drawing efficiency and product yield, and has good prospects for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 The XPS spectra of the grafted graphite / graphene oxide provided in Examples 1 to 3 of the present invention; Figure 2Comparative graph of the adhesion of the composite drawing graphite emulsion prepared in Examples 1 to 3 of the present invention and the unmodified graphite emulsion on the surfaces of tungsten, molybdenum and titanium; Figure 3 SEM comparison of the composite drawing graphite emulsion prepared in Examples 1 to 3 of the present invention after being used for drawing different metal microwires; Figure 4 This is a comparison chart of the free circle diameters of the composite drawing graphite emulsions prepared in Examples 1 to 3 of the present invention when used for drawing different metal microwires; Figure 5 This is a comparison chart of the free circle diameters of the composite drawing graphite emulsions prepared in Comparative Examples 1 to 6 of the present invention when used for drawing different metal microwires. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] The present invention will be further described below with reference to specific examples, and the scope of protection of the present invention is not limited by the following examples. Unless otherwise specified, the materials mainly involved in the following examples are conventional commercial products or raw materials that can be prepared by existing known chemical methods.

[0023] In the present invention, the method for grafting carboxyl groups onto the surfaces of graphite and graphene oxide is as follows: 5g of graphite and 0.05g of graphene oxide are placed in 150ml of concentrated sulfuric acid, 2g of sodium nitrate is added, and a magnetic stirrer is turned on at a stirring speed of 200 rpm. The mixture is stirred in an ice-water bath for 20 minutes, ensuring that the temperature of the reaction system is below 5°C. Then, 22.5g of potassium permanganate is slowly added, and stirring is continued for 2 hours while maintaining the low temperature. After the temperature is raised to 25°C, stirring is continued for 6 hours. The graphite / graphene oxide grafted with carboxyl groups is obtained after filtration, washing, and drying.

[0024] In the present invention, the method for grafting epoxy groups on the surface of graphite and graphene oxide is as follows: 5g of graphite and 0.05g of graphene oxide are dispersed in 100mL of peracetic acid solution, a magnetic stirrer is turned on, the stirring speed is 200r / min, and the mixture is stirred in a constant temperature water bath at 40°C for 4h. After the reaction is completed, the epoxy-grafted graphite / graphene oxide is obtained by filtering, washing and drying.

[0025] In the present invention, the method for grafting sulfonic acid groups onto the surfaces of graphite and graphene oxide is as follows: 5 g of graphite and 0.05 g of graphene oxide are placed in 150 ml of concentrated sulfuric acid, and a magnetic stirrer is turned on at a stirring speed of 200 r / min. The mixture is stirred in an ice-water bath for 20 minutes, ensuring that the reaction system temperature is below 5°C. Then, 7.5 mL of chlorosulfonic acid is slowly added, and stirring is continued for 2 hours while maintaining the low temperature. After the temperature is raised to 25°C, stirring is continued for 6 hours. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the graphite / graphene oxide grafted with sulfonic acid groups.

[0026] It should be noted that the present invention treats graphite and graphene oxide separately when modifying them.

[0027] The following are specific embodiments of the present invention.

[0028] Example 1 This embodiment provides a composite drawing graphite emulsion, which includes the following components, calculated by mass percentage: 15% carboxyl grafted graphite / carboxyl grafted graphene oxide, 3% dispersant, 1% thickener, 2% binder, 3% organic additive ethylene glycol, 2% ammonia water, and the balance is water; the modified graphene oxide is 2wt% of the mass of the modified graphite, and the mass ratio of carbon and oxygen elements of the carboxyl grafted graphite and the carboxyl grafted graphene oxide is 1:1.

[0029] The composite drawing graphite emulsion is prepared by the following steps: Carboxyl grafted graphite, carboxyl grafted graphene oxide and dispersant are added to water, and a dispersion is obtained after magnetic stirring at 200 r / min. A thickener, a binder, an organic additive and ammonia water are added in sequence and mixed evenly. Finally, the mixture is placed in a high-energy ball mill and ball milled at 300 r / min for 8 hours to obtain a uniformly dispersed drawing graphite emulsion.

[0030] The prepared graphite emulsion has a solid content of 22%, a pH of 10, and an ash content of 0.8%.

[0031] Example 2 This embodiment provides a composite drawing graphite emulsion, which includes the following components, calculated by mass percentage: 18% epoxy grafted graphite / epoxy grafted graphene oxide, 5% dispersant, 3% thickener, 4% binder, 3% organic additive polyvinyl alcohol, 4% ammonia water, and the balance water; the modified graphene oxide is 1wt% of the mass of the modified graphite, and the mass ratio of carbon and oxygen elements of the epoxy grafted graphite and the epoxy grafted graphene oxide is 1:0.8.

[0032] The composite drawing graphite emulsion is prepared by the following steps: Epoxy-grafted graphite, epoxy-grafted graphene oxide and dispersant are added to water, and a dispersion is obtained after magnetic stirring at 200 r / min. A thickener, a binder, an organic additive and ammonia water are added in sequence and mixed evenly. Finally, the mixture is placed in a high-energy ball mill and ball milled at 350 r / min for 10 hours to obtain a uniformly dispersed drawing graphite emulsion.

[0033] The prepared graphite emulsion has a solid content of 30%, a pH of 11, and an ash content of 1%.

[0034] Example 3 The embodiment provides a composite drawing graphite emulsion, which includes the following components, calculated by mass percentage: 22% sulfonic acid grafted graphite / sulfonic acid grafted graphene oxide, 5% dispersant, 3% thickener, 4% binder, 3% organic additive ethylene glycol butyl ether, 4% ammonia water, and the balance is water; the modified graphene oxide is 0.1wt% of the mass of the modified graphite, and the mass ratio of carbon and oxygen elements of the sulfonic acid grafted graphite and the sulfonic acid grafted graphene oxide is 1:1.2.

[0035] The composite drawing graphite emulsion is prepared by the following steps: Sulfonic acid grafted graphite, sulfonic acid grafted graphene oxide and dispersant are added to water, and a dispersion is obtained after magnetic stirring at 200 r / min. A thickener, a binder, an organic additive and ammonia water are added in sequence and mixed evenly. Finally, the mixture is placed in a high-energy ball mill and ball milled at 400 r / min for 12 hours to obtain a uniformly dispersed drawing graphite emulsion.

[0036] The prepared graphite emulsion has a solid content of 35%, a pH of 10, and an ash content of 0.8%.

[0037] Comparative Example 1 The difference from Example 3 is that: no sulfonyl-grafted graphene oxide is included, and the other components and their amounts are the same; The drawing graphite emulsion is prepared by the following steps: Sulfonic acid grafted graphite and dispersant are added to water, and a dispersion is obtained after magnetic stirring at 200 r / min. A thickener, a binder, an organic additive and ammonia water are added in sequence and mixed evenly. Finally, the mixture is placed in a high-energy ball mill and ball milled at 400 r / min for 12 hours to obtain a uniformly dispersed drawing graphite emulsion.

[0038] The prepared graphite emulsion has a solid content of 35%, a pH of 10, and an ash content of 0.8%.

[0039] Comparative Example 2 The difference from Example 3 is that the modified graphene oxide is 5 wt % of the mass of the modified graphite.

[0040] The composite drawing graphite emulsion is prepared by the following steps: The sulfonic acid group grafted graphite, sulfonic acid group grafted graphene oxide and dispersant are added into water, and a dispersion liquid is obtained after magnetic stirring at 200 r / min, and then a thickening agent, a binder, an organic additive and ammonia are sequentially added and uniformly mixed, and finally the mixture is placed in a high-energy ball mill and ball milled at 400 r / min for 12 h to obtain a uniformly dispersed drawing graphite emulsion.

[0041] The prepared graphite emulsion has a solid content of 35%, pH=10 and ash content of 1%.

[0042] Comparative Example 3 The difference from Example 3 is that the mass ratio of carbon to oxygen elements of the sulfonic acid group grafted graphite and the sulfonic acid group grafted graphene oxide is 1:0.4.

[0043] The composite drawing graphite emulsion is prepared by the following steps: The sulfonic acid group grafted graphite, sulfonic acid group grafted graphene oxide and dispersant are added into water, and a dispersion liquid is obtained after magnetic stirring at 200 r / min, and then a thickening agent, a binder, an organic additive and ammonia are sequentially added and uniformly mixed, and finally the mixture is placed in a high-energy ball mill and ball milled at 400 r / min for 12 h to obtain a uniformly dispersed drawing graphite emulsion.

[0044] The prepared graphite emulsion has a solid content of 35%, pH=10 and ash content of 0.8%.

[0045] Comparative Example 4 The difference from Example 3 is that the mass ratio of carbon to oxygen elements of the sulfonic acid group grafted graphite and the sulfonic acid group grafted graphene oxide is 1:1.5.

[0046] The composite drawing graphite emulsion is prepared by the following steps: The sulfonic acid group grafted graphite, sulfonic acid group grafted graphene oxide and dispersant are added into water, and a dispersion liquid is obtained after magnetic stirring at 200 r / min, and then a thickening agent, a binder, an organic additive and ammonia are sequentially added and uniformly mixed, and finally the mixture is placed in a high-energy ball mill and ball milled at 400 r / min for 12 h to obtain a uniformly dispersed drawing graphite emulsion.

[0047] The prepared graphite emulsion has a solid content of 35%, pH=10 and ash content of 0.8%.

[0048] Comparative Example 5 The difference from Example 3 is that the graphene oxide surface is not grafted with sulfonic acid groups.

[0049] The composite drawing graphite emulsion is prepared by the following steps: Sulfonic acid grafted graphite, graphene oxide and dispersant are added to water, and a dispersion is obtained after magnetic stirring at 200 r / min. A thickener, a binder, an organic additive and ammonia water are added in sequence and mixed evenly. Finally, the mixture is placed in a high-energy ball mill and ball milled at 400 r / min for 12 hours to obtain a uniformly dispersed drawing graphite emulsion.

[0050] The prepared graphite emulsion has a solid content of 34%, a pH of 10, and an ash content of 0.8%.

[0051] Comparative Example 6 The difference from Example 3 is that no sulfonic acid groups are grafted onto the graphite surface.

[0052] The composite drawing graphite emulsion is prepared by the following steps: Graphite, sulfonic acid-grafted graphene oxide and dispersant are added to water, and a dispersion is obtained after magnetic stirring at 200 r / min. A thickener, a binder, an organic additive and ammonia water are added in sequence and mixed evenly. Finally, the mixture is placed in a high-energy ball mill and ball milled at 400 r / min for 12 hours to obtain a uniformly dispersed drawing graphite emulsion.

[0053] The prepared graphite emulsion has a solid content of 33%, a pH of 10, and an ash content of 0.8%.

[0054] Examples 1 to 3 were used for drawing 30 μm tungsten wire, 28 μm molybdenum wire, and 25 μm titanium wire, respectively. The drawing objects of Comparative Examples 1 to 6 were the same as those of Example 3. The process is as follows: During the wire drawing process, the metal microwires first pass through the corresponding graphite emulsion, and after high-temperature baking, the graphite emulsion is completely dried, forming a dense graphite layer on the surface of the metal microwires, which plays a role in wire drawing lubrication. The drawing results are shown in FIG. Figures 1 to 5 shown.

[0055] Figure 1 The XPS spectra of graphite / graphene oxide after grafting treatment in Examples 1, 2, and 3 are shown. Figure 1 It can be seen that different oxygen-containing functional groups are grafted onto graphite / graphene oxide after treatment, so a more significant oxygen peak is shown in the XPS spectrum. For the different functional groups grafted in these three embodiments, the XPS spectrum is carefully separated by peak analysis. It is found that the peak separation results of Example 1 show that it has a relatively high C=O peak, indicating that it is grafted with a carboxyl group; Example 2 has a higher content of COC, indicating that it is grafted with an epoxy group; and a peak of the S element appears in Example 3, indicating that it is grafted with a sulfonic acid group.

[0056] Figure 2 The graphs show the adhesion comparison of the graphite emulsions prepared in Examples 1, 2, and 3 and the graphite emulsions without modification of graphite / graphene oxide on the surfaces of tungsten, molybdenum, and titanium. Figure 2It can be seen that the current unmodified graphite emulsion only shows good adhesion on tungsten surfaces, while its adhesion performance on molybdenum and titanium surfaces is poor. The present application grafts corresponding functional groups on the surface of graphite / graphene oxide. These oxygen-containing functional groups serve as reactive sites and can bond with the oxide layer on the surface of metal microwires at high temperatures. This not only improves the adhesion of graphite emulsion on tungsten surfaces, but also significantly enhances its adhesion on molybdenum and titanium metal surfaces. This improvement enables the graphite emulsion to form a more stable graphite lubricating layer during the drawing process, thereby significantly improving the lubrication effect and ensuring the quality of the metal microwire surface and processing efficiency.

[0057] Figure 3 The SEM comparison of the graphite emulsions prepared in Examples 1, 2, and 3 after being used for drawing different metal microwires. Figure 3 It can be seen that after the graphite emulsions prepared in Examples 1, 2, and 3 are used for drawing different metal microwires, the surfaces of the metal microwires are relatively flat and smooth, without scratches or cracks on the surface, indicating that the prepared graphite emulsions have excellent lubrication properties during the drawing process of different metal microwires.

[0058] Figure 4 The following is a comparison chart of the free circle diameters of the graphite emulsions prepared in Examples 1, 2, 3 and Comparative Examples 1 and 2 for drawing different metal microwires. Figure 4 It can be seen that the diameters of the metal microwires after drawing the graphite emulsions prepared in Examples 1, 2, and 3 are 46 mm, 48 mm, and 55 mm, respectively, all of which meet the application standards of microwires.

[0059] Figure 5 The free ring diameter comparison chart of graphite emulsions prepared in different comparison ratios after being applied to titanium wire drawing is shown. Figure 5 It can be seen that Comparative Examples 1 and 2 change the amount of sulfonic acid grafted graphene oxide added. No sulfonic acid grafted graphene oxide is added in Comparative Example 1, and sulfonic acid grafted graphene oxide helps to enhance the strength of the graphite lubricating layer. Therefore, the graphite layer formed in the drawing process of the graphite emulsion without adding graphene oxide in Comparative Example 1 is insufficient in strength, the lubrication performance is reduced, and the diameter of the titanium wire ring after drawing is reduced; in Comparative Example 2, an excessive amount of sulfonic acid grafted graphene oxide is added, resulting in a decrease in the relative content of sulfonic acid grafted graphite in the system, and an inability to form a graphite layer of a certain thickness on the surface of the metal microwire, so the lubrication ability is also reduced.

[0060] Depend on Figure 5It can also be seen that the carbon-oxygen mass ratio of the composite drawing graphite emulsion prepared in Comparative Example 3 is 1:0.4, and the diameter of the drawn titanium wire is only 25 mm. This is because the proportion of sulfonic acid groups grafted into the graphite / graphene oxide is relatively low, resulting in insufficient adhesion of the graphite layer to the titanium wire surface, which is prone to falling off, resulting in a lower diameter. The carbon-oxygen mass ratio of the composite drawing graphite emulsion prepared in Comparative Example 4 is 1:1.5, and the diameter of the drawn titanium wire is even lower than that of Comparative Example 3. Analysis shows that the reason for this may be that the excessive sulfonic acid groups grafted into the graphite / graphene oxide destroy the graphite lattice structure, thereby failing to exert its lubricating effect, resulting in the lowest diameter.

[0061] Comparing Example 3 with Comparative Examples 5 and 6, we can see that in Comparative Example 5, only the sulfonic acid group-grafting treatment on graphite prevented the graphene oxide from adhering to the metal microwire surface, leading to aggregation and shedding of small pieces, significantly reducing the coil diameter of the titanium wire. In Comparative Example 6, only the sulfonic acid group-grafting treatment on graphene oxide resulted in insufficient adhesion of the graphite as the main component to the titanium surface, making it even more difficult to form a high-strength lubricating layer on the titanium wire surface. Consequently, the coil diameter of the titanium wire after drawing was also reduced.

[0062] 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, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A composite drawing graphite emulsion for drawing different metal microwires, characterized in that: The invention comprises the following components by mass percentage: 15% to 22% of modified graphite / modified graphene oxide, 3% to 5% of dispersant, 1% to 5% of thickener, 2% to 8% of binder, 3% to 5% of organic additive, 2% to 4% of ammonia water, and the balance of water; The modified graphite / modified graphene oxide are both graphite and graphene oxide whose surfaces are modified with oxygen-containing functional groups.

2. The composite drawing graphite emulsion for drawing different metal microwires according to claim 1, characterized in that: The oxygen-containing functional group is selected from one or more of a carboxyl group, an epoxy group, and a sulfonic acid group.

3. The composite drawing graphite emulsion for drawing different metal microwires according to claim 1, characterized in that: The modified graphene oxide is 0.1 wt% to 2.0 wt% of the mass of the modified graphite.

4. The composite drawing graphite emulsion for drawing different metal microwires according to claim 3, characterized in that: The mass ratio of the modified graphene oxide to the total carbon element and the total oxygen element in the modified graphite is 1: (0.8-1.2).

5. The composite drawing graphite emulsion for drawing different metal microwires according to claim 1, characterized in that: The organic auxiliary agent is selected from one or more of ethylene glycol, polyvinyl alcohol, and ethylene glycol butyl ether.

6. A method for preparing a composite drawing graphite emulsion for drawing different metal microwires according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Surface modification of graphite and graphene oxide to obtain modified graphite and modified graphene oxide; S2. Prepare materials according to the mass percentage, add modified graphite, modified graphene oxide and dispersant into water, stir, add thickener, binder, organic additive and ammonia water, ball mill to obtain drawing graphite emulsion.

7. The method for preparing a composite drawing graphite emulsion for drawing different metal microwires according to claim 6, characterized in that: In step S1, the modification process includes: Under stirring conditions, graphite and graphene oxide are dispersed in concentrated sulfuric acid with sodium nitrate respectively, followed by adding potassium permanganate, stirring is continued at 0-5°C for 2-4 hours, and then maintained at 20-28°C for 6-8 hours, filtered, washed, and dried to obtain graphite or graphene oxide with carboxyl groups grafted on the surface; Alternatively, graphite and graphene oxide are dispersed in peracetic acid and sodium acetate solutions respectively, stirred at 30-40° C. for 4-5 hours, and after the reaction is completed, filtered, washed, and dried to obtain graphite or graphene oxide with epoxy groups grafted on the surface; Alternatively, graphite and graphene oxide are placed in concentrated sulfuric acid and stirred for 10 to 20 minutes, followed by adding chlorosulfonic acid, and stirring is continued at 0 to 5°C for 2 to 4 hours, and then maintained at 20 to 28°C for 6 to 8 hours, filtered, washed, and dried to obtain graphite or graphene oxide with sulfonic acid groups grafted on the surface.

8. The method for preparing a composite drawing graphite emulsion for drawing different metal microwires according to claim 6, characterized in that: In step S2, the ball milling speed is 300-400 r / min, and the time is 8-12 h.

9. A method for drawing metal microwires, characterized in that: The composite drawing graphite emulsion for drawing different metal microwires as described in any one of claims 1 to 5 is used as a lubricant.

10. The method for drawing metal microwires according to claim 9, wherein: The method is applicable to drawing microwires of different metal materials within a diameter range of 25 to 30 μm, and the coil diameter of the metal microwire obtained after drawing is not less than 40 mm.

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