Preparation method of graded porous carbon-copper composite material

Abstract

The invention discloses a preparation method of a graded porous carbon-copper composite material. The preparation method comprises the following steps: 1, selecting raw materials; 2, mixing polyethylene glycol with potassium carbonate powder; step 3, high-temperature carbonization; step 4, removing potassium carbonate by water dissolution; 5, mixing with copper powder; step 6, hot pressed sintering; the preparation method has the beneficial effects that potassium carbonate is used as a template for improving the internal structure of the carbon material in the synthesis process, so that the carbon material forms a three-dimensional hierarchical porous structure, then the carbon-copper composite material is prepared by adopting a hot pressing sintering method, and porous carbon and copper are subjected to cross-linking combination through the three-dimensional interconnected pore structure, so that the carbon-copper composite material is prepared. A carbon-copper network structure complementary composite material is formed, and mutual cross-linking compounding of the carbon material and copper is enhanced; the problem that the internal structure of porous carbon is difficult to control is solved, and the surface of a carbon material does not need to be pretreated; the preparation method is easy to operate, low in raw material requirement and low in cost, and the produced carbon-copper composite material is good in density and excellent in heat-conducting property.

Description

Technical Field

[0001] The invention relates to the technical field of carbon-copper composite materials, and in particular to a method for preparing a graded porous carbon-copper composite material. Background Art

[0002] Carbon materials have stable physical and chemical properties and excellent electrical and thermal conductivity, and have excellent applications in light, electricity, heat, force, etc.; carbon materials such as graphene, carbon fiber, and carbon nanotubes are compounded with copper to form carbon-copper composite materials. Since copper has good electrical and thermal conductivity, carbon-copper composite materials are an advanced composite material that combines carbon and copper. Carbon-copper composite materials have a wide range of applications in many fields. 1. Application in the electronics field: Carbon-copper composite materials are mainly used to manufacture electrodes and conductive materials. This makes carbon-copper composite materials an ideal choice for manufacturing high-quality electrodes. At the same time, they can also be used to manufacture conductive lines in printed circuit boards to improve the performance and stability of electronic equipment. 2. Application in the aerospace field: Carbon-copper composite materials are favored for their light weight, high strength, and high conductivity. They are used to manufacture structural components of aircraft and spacecraft, such as wings and fuselages. At the same time, they can also be used to manufacture thermal protection systems for aerospace vehicles, effectively protecting aircraft from damage in high-temperature environments. 3. Application in the automotive industry: Carbon-copper composite materials are widely used in the manufacture of automotive parts, such as brake pads, bearings, and gears. These components need to withstand harsh conditions such as high temperature and high pressure, and carbon-copper composite materials have excellent wear resistance and fatigue resistance, which can meet these stringent requirements. At the same time, they can also be used to manufacture conductive components for electric vehicles to improve the performance and range of electric vehicles. In short, carbon-copper composite materials play an increasingly important role in modern industry and are increasingly widely used due to their unique properties and wide range of applications.

[0003] The preparation method of carbon-copper composite materials in the prior art has the following disadvantages: 1. Due to the poor interface wettability between carbon and copper in carbon-copper composite materials, it is difficult to form a good interface bonding only by mechanical bonding; 2. The existing preparation cost is high and the process is complicated; 3. It is difficult to produce porous carbon with a hierarchical pore structure in the existing preparation; 4. The mutual bonding strength between carbon material and copper is low; 5. The existing preparation requires pre-treatment of the carbon material surface, and the process is cumbersome; 5. The density of the existing materials is not high enough, the thermal conductivity is not strong enough, and the preparation cost is high. Summary of the invention

[0004] The present invention aims to solve the above problems and provides a method for preparing a graded porous carbon-copper composite material, which strengthens the cross-linking and compounding of carbon material and copper, is simple to operate, has low requirements for raw materials, and is low in cost. The produced carbon-copper composite material has good density and excellent thermal conductivity.

[0005] To achieve the above object, the present invention provides a method for preparing a hierarchical porous carbon-copper composite material, characterized in that the preparation method comprises the following steps:

[0006] S1. Select raw materials: select polyethylene glycol, potassium carbonate powder, and copper powder, and grind the potassium carbonate powder through a grinder;

[0007] S2, mixing polyethylene glycol with potassium carbonate powder: mixing polyethylene glycol and potassium carbonate powder to obtain agglomerated solids of potassium carbonate and polyethylene glycol;

[0008] S3, high temperature carbonization: high temperature carbonization of potassium carbonate and polyethylene glycol agglomerated solid to obtain a mixed powder of carbonization product and potassium carbonate;

[0009] S4, removing potassium carbonate by water dissolution: putting the mixed powder of the carbonization product and potassium carbonate into water and stirring to remove potassium carbonate, and then drying to obtain graded porous carbon powder;

[0010] S5, mixing with copper powder: mixing the graded porous carbon powder and the copper powder to obtain a mixed powder of graded porous carbon and copper;

[0011] S6, hot pressing sintering: sintering the mixed powder of graded porous carbon and copper in a sintering device.

[0012] Finally, a hierarchical porous carbon-copper composite material is obtained.

[0013] Furthermore, in step S1, the relative molecular weights of the polyethylene glycol and potassium carbonate powder are 150-300; the polyethylene glycol is in liquid state; and the copper powder is fine copper, and the particle size of the copper powder is 1-2 μm.

[0014] Furthermore, in step S1, the grinding speed of the pulverizer is 2000-3000 rpm, and the grinding time is 30-90 minutes.

[0015] Furthermore, in step S2, the mass ratio of the polyethylene glycol to potassium carbonate is 2:8 to 8:2, and the preferred mass ratio is 1:1.

[0016] Furthermore, in step S2, the potassium carbonate powder and polyethylene glycol are uniformly mixed and stirred to obtain agglomerated solids of potassium carbonate and polyethylene glycol.

[0017] Furthermore, in step S3, the potassium carbonate and polyethylene glycol agglomerated solids are placed in a carbonization device for carbonization to obtain a mixed powder of the carbonization product and potassium carbonate; the carbonization device is a tubular furnace, and the carbonization temperature is 800-1100°C, preferably 1000°C.

[0018] Furthermore, in step S4, the mixed powder of the carbonization product and potassium carbonate is placed in water and stirred to remove the potassium carbonate, then filtered and placed in a drying oven for drying to obtain graded porous carbon powder; the stirring time is 8 to 16 hours; the drying time is 8 to 16 hours, and the water is distilled water.

[0019] Furthermore, in step S5, the graded porous carbon powder is evenly dispersed in ethanol, copper powder is added, stirred evenly, and then placed in a drying oven for drying to obtain a mixed powder of graded porous carbon and copper; the mixing mass ratio of the graded porous carbon powder and the copper powder is 3:7 to 5:5, and the preferred mass ratio is 4:6; the temperature of the drying oven is 60 to 80°C; the ethanol is anhydrous ethanol.

[0020] Furthermore, in step S6, the mixed powder of the graded porous carbon and copper is evenly mixed in a mixer, placed in a hot pressing mold, and then the hot pressing mold is placed in a sintering device for sintering; the sintering device is a vacuum hot pressing sintering furnace; during the sintering process of the vacuum hot pressing sintering furnace, the furnace is evacuated until the vacuum degree is 10 -2 ~10 -4 Pa, then increase the temperature and pressure at a rate of 10 to 20°C / minute, when the temperature rises to 400 to 500°C, keep warm for 7 to 15 minutes, and continue to heat until the temperature is 950 to 1100°C and the pressure reaches 35 to 45MPa, maintain the sintering time for 0.5 to 1.5 hours, then cool and reduce the pressure with the furnace, and finally obtain a sintered rough blank, i.e., a graded porous carbon-copper composite material; the optimal temperature in the furnace is 1000°C; the time for uniform mixing in the mixer is 1 to 3 hours; and the hot pressing mold is a graphite mold.

[0021] Furthermore, after step S6, there is step S7; step S7 is machining, that is, the sintered rough blank is machined into a specific shape and size.

[0022] The beneficial effects of the present invention are as follows: 1. It solves the problem that the internal structure of porous carbon is difficult to control; 2. Low-cost potassium carbonate is used as a template to improve the internal structure of carbon materials during the synthesis process, the carbon source and the pore-forming template are carbonized at high temperature, and porous carbon with a hierarchical pore structure is prepared by one-step pyrolysis using a template method; 3. Porous carbon and copper powder are evenly mixed, and then a carbon-copper composite material is prepared in one step using a hot pressing sintering method. The porous carbon can be cross-linked with copper through its three-dimensional interconnected pore structure to form a composite material with a complementary carbon-copper network structure, thereby strengthening the cross-linking and compounding of carbon materials and copper; 4. The preparation method is simple to operate, has low requirements for raw materials, and is low in cost; 5. The produced hierarchical porous carbon-copper composite material has good density, high purity, and excellent thermal conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the description are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a flow chart of the preparation method of the invention.

[0025] Figure 2 It is an invented hierarchical porous carbon three-dimensional structure model.

[0026] Figure 3 This is a scanning electron microscope image of the invented hierarchical porous carbon.

[0027] The following is a further description of the implementation, functional features and advantages of the present invention with reference to the embodiments and accompanying drawings. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the 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 work are within the scope of protection of the present invention.

[0029] Embodiment 1:

[0030] like Figure 1 , Figure 2 , Figure 3 As shown, a hierarchical porous carbon-copper composite material is prepared, the size of which is 50*50*4mm, and the preparation method thereof is as follows:

[0031] Step 1. Select liquid polyethylene glycol with model PEG-200, AR-grade potassium carbonate powder, and fine copper powder, and prepare a 50*50 graphite mold; the copper powder particle size of the fine copper powder is 1 μm; weigh 5 kg of potassium carbonate powder and crush it in a grinder, specifically using a speed of 2500 rpm for 30 minutes; the crushing time can be 30 to 90 minutes, which can be adjusted according to the powder state.

[0032] Step 2: Move the crushed potassium carbonate powder into a quartz container, slowly pour 5 kg of polyethylene glycol into the quartz container, and stir while pouring until the potassium carbonate and the polyethylene glycol are evenly mixed to obtain agglomerated solids of potassium carbonate and polyethylene glycol; the mass ratio of the mixture of polyethylene glycol and potassium carbonate is 2:8 to 8:2, which can be freely adjusted according to the required internal pore structure, and the preferred mass ratio is 1:1.

[0033] Step 3: Load potassium carbonate and polyethylene glycol lumpy solids into quartz containers in batches, and push all quartz containers into a tubular furnace that is always filled with nitrogen. When the temperature in the high-temperature zone reaches 1000°C, push the quartz containers into the high-temperature zone for carbonization. The carbonization time is 1 hour to obtain a mixed powder of the carbonized product and potassium carbonate.

[0034] Step 4: Place the mixed powder of the carbonization product and potassium carbonate in distilled water and stir for 12 hours to remove the potassium carbonate, then filter and place in a drying oven for 12 hours to obtain graded porous carbon powder.

[0035] Step 5: Evenly disperse the graded porous carbon powder in anhydrous ethanol, add 2.4 kg of fine copper powder, stir well, and then place in a drying oven to dry the ethanol at 70° C. to obtain a mixed powder of graded porous carbon and copper.

[0036] Step 6: Place the mixed powder of graded porous carbon and copper in a V-type mixer for mixing for 2 hours, then weigh 72g of the mixed powder and place it in a graphite mold, then place the graphite mold in a vacuum hot pressing sintering furnace, and evacuate the furnace until the vacuum degree is 10 -3 Pa, then slowly increase the temperature and pressure at a heating rate of 15°C / minute. When the temperature reaches 450°C, keep warm for 10 minutes, and then continue to heat up until the temperature reaches 1000°C and the pressure reaches 40MPa. Keep sintering for 1 hour, then cool and reduce the pressure with the furnace, and finally obtain a sintered rough blank, that is, a graded porous carbon-copper composite material. Pa is the pressure unit Pascal, and MPa is the abbreviation of megapascal.

[0037] The subsequent step seven, machining forming, is to machine the sintered rough blank into a specific shape and size; machining includes turning, milling, planing, drilling, grinding and other methods to process the rough blank to a specific size.

[0038] Embodiment 2:

[0039] like Figure 1 , Figure 2 , Figure 3 As shown, a graded porous carbon-copper composite material is prepared, the size of which is 50*50*4mm. The difference between this embodiment and Example 1 is that the raw material ratio used to prepare the graded porous carbon powder, namely potassium carbonate: polyethylene glycol, is 3:7; the rest is the same as Example 1.

[0040] Embodiment 3:

[0041] like Figure 1 , Figure 2 , Figure 3As shown, a graded porous carbon-copper composite material is prepared, the size of which is 50*50*4mm. The difference between this embodiment and Example 1 is that the raw material ratio used to prepare the graded porous carbon powder, namely potassium carbonate: polyethylene glycol, is 7:3; the rest is the same as Example 1.

[0042] Table 1 Density and thermal conductivity parameters of hierarchical porous carbon-copper composites

[0043] Density(%) Thermal conductivity (W / mK) Example 1 99.8 340 Example 2 94.3 309 Example 3 95.6 313

[0044] Through Table 1, and comparing Example 1 with Example 2 and Example 3, it can be seen that the graded porous carbon-copper composite material prepared by the present invention has good density and excellent thermal conductivity; by changing the ratio of potassium carbonate to polyethylene glycol, the prepared material will have different density and thermal conductivity; at the same time, it can be seen that Example 1 has the best density and thermal conductivity.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents, and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a hierarchical porous carbon-copper composite material, characterized in that: The preparation method steps are as follows: S1. Select raw materials: select polyethylene glycol, potassium carbonate powder, and copper powder, and grind the potassium carbonate powder through a grinder; S2, mixing polyethylene glycol with potassium carbonate powder: mixing polyethylene glycol and potassium carbonate powder to obtain agglomerated solids of potassium carbonate and polyethylene glycol; S3, high temperature carbonization: high temperature carbonization of potassium carbonate and polyethylene glycol agglomerated solid to obtain a mixed powder of carbonization product and potassium carbonate; S4, removing potassium carbonate by water dissolution: putting the mixed powder of the carbonization product and potassium carbonate into water and stirring to remove potassium carbonate, and then drying to obtain graded porous carbon powder; S5, mixing with copper powder: mixing the graded porous carbon powder and the copper powder to obtain a mixed powder of graded porous carbon and copper; S6. Hot pressing sintering: sintering the mixed powder of graded porous carbon and copper in a sintering device to finally obtain a graded porous carbon-copper composite material.

2. The method for preparing a hierarchical porous carbon-copper composite material according to claim 1, characterized in that: In step S1, the relative molecular weights of the polyethylene glycol and potassium carbonate powder are 150-300; the polyethylene glycol is in liquid state; the copper powder is fine copper, and the copper powder particle size is 1-2 μm.

3. The method for preparing a hierarchical porous carbon-copper composite material according to claim 2, characterized in that: In step S1, the grinding speed of the pulverizer is 2000-3000 rpm, and the grinding time is 30-90 minutes.

4. The method for preparing a hierarchical porous carbon-copper composite material according to claim 3, characterized in that: In step S2, the mass ratio of the polyethylene glycol to potassium carbonate is 2:8 to 8:2, and the preferred mass ratio is 1:

1.

5. The method for preparing a hierarchical porous carbon-copper composite material according to claim 4, characterized in that: In step S2, the potassium carbonate powder and the polyethylene glycol are uniformly mixed and stirred to obtain agglomerated solids of potassium carbonate and polyethylene glycol.

6. The method for preparing a hierarchical porous carbon-copper composite material according to claim 5, characterized in that: In step S3, the potassium carbonate and polyethylene glycol agglomerated solids are placed in a carbonization device for carbonization to obtain a mixed powder of the carbonization product and potassium carbonate; the carbonization device is a tubular furnace, and the carbonization temperature is 800-1100°C, preferably 1000°C.

7. The method for preparing a hierarchical porous carbon-copper composite material according to claim 6, characterized in that: In step S4, the mixed powder of the carbonization product and potassium carbonate is placed in water and stirred to remove the potassium carbonate, then filtered and placed in a drying oven for drying to obtain graded porous carbon powder; the stirring time is 8 to 16 hours; the drying time is 8 to 16 hours, and the water is distilled water.

8. The method for preparing a hierarchical porous carbon-copper composite material according to claim 7, characterized in that: In step S5, the graded porous carbon powder is evenly dispersed in ethanol, copper powder is added, stirred evenly, and then placed in a drying oven for drying to obtain a mixed powder of graded porous carbon and copper; the mixing mass ratio of the graded porous carbon powder and the copper powder is 3:7 to 5:5, and the preferred mass ratio is 4:6; the temperature of the drying oven is 60 to 80°C; the ethanol is anhydrous ethanol.

9. The method for preparing a hierarchical porous carbon-copper composite material according to claim 8, characterized in that: In step S6, the mixed powder of graded porous carbon and copper is evenly mixed in a mixer, placed in a hot pressing mold, and then placed in a sintering device for sintering; the sintering device is a vacuum hot pressing sintering furnace; during the sintering process of the vacuum hot pressing sintering furnace, the furnace is evacuated until the vacuum degree is 10 -2 ~10 -4 Pa, then increase the temperature and pressure at a rate of 10 to 20°C / minute, when the temperature rises to 400 to 500°C, keep warm for 7 to 15 minutes, and continue to heat until the temperature is 950 to 1100°C and the pressure reaches 35 to 45MPa, maintain the sintering time for 0.5 to 1.5 hours, then cool and reduce the pressure with the furnace, and finally obtain a sintered rough blank, i.e., a graded porous carbon-copper composite material; the optimal temperature in the furnace is 1000°C; the time for uniform mixing in the mixer is 1 to 3 hours; and the hot pressing mold is a graphite mold.

10. The method for preparing a hierarchical porous carbon-copper composite material according to claim 9, characterized in that: After step S6, there is step S7; step S7 is machining, that is, the sintered rough blank is machined into a specific shape and size.

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