TW202006144A - Manufacturing method of graphene metal composite material - Google Patents

Abstract

A manufacturing method of a graphene metal composite material having following steps is provided: providing a metal powder, a graphene powders and a binder and mixing into a powder raw material, each graphene piece is bound with a function group by a triple covalent bond, the triple covalent bond is heated and broken by frictional, the functional groups are separated from the graphene, and the graphene are connected with each other by the triple covalent bond to wrap the respective metal particles; melting and molding the powder raw; debinding sequentially by solution and heating up to 140 ° C to 170 ° C; sintering to form a three-dimensional graphene mash embedded in a metal body.

Description

Graphene metal composite manufacturing method

The invention relates to a graphene metal composite material, in particular to a method for manufacturing graphene metal composite material in which graphene is uniformly mixed.

At present, the preparation and application of silicon carbide and alumina-reinforced copper-based composite materials have matured, but their comprehensive performance and actual needs are still some distance away, and graphene has excellent mechanical properties, thermal properties and electrical properties. One of the most ideal reinforcements of thermally conductive composite materials. However, research on graphene-reinforced copper-aluminum-based composite materials is still in its infancy, and related research work is urgently needed. How to disperse graphene evenly in the copper-aluminum matrix, and at the same time make graphene and metal form a good contact interface without destroying the microstructure of graphene is a key problem in the research.

In view of this, the present inventors have made great efforts to study the above-mentioned prior art and cooperate with the application of academic principles, and try their best to solve the above-mentioned problems, which becomes the improvement goal of the present inventors.

The invention provides a method for manufacturing graphene metal composite materials in which graphene is uniformly mixed.

The invention provides a method for manufacturing a graphene metal composite material, which includes the following steps: providing metal powder, graphene powder and an adhesive, the metal powder includes a plurality of metal particles, the adhesive includes a wax material, and the graphene powder includes a plurality of graphene microparticles Each graphene microchip contains a plurality of connected graphene molecules. Each graphene molecule contains six carbon atoms connected in a ring. One of the carbon atoms in each graphene molecule is connected to a functional group by a trivalent covalent bond. . The metal powder, graphene powder and adhesive are mixed into a powder raw material, and the mixed friction generates heat to break the three covalent bonds of each functional group after absorbing heat. After the functional groups are separated from each graphene molecule, each graphene molecule borrows The other three graphene molecules are bonded by the broken three covalent bonds to make the graphene molecules coat the metal particles. The powder raw material is heated to melt into a liquid mixed raw material, and the liquid mixed raw material includes the metal powder, the liquid adhesive and the graphene powder. The liquid mixed raw material is injected into a mold for injection molding and solidified into an initial embryo. Remove the adhesive in the initial embryo to form a dewaxed semi-finished product. Solvent dewaxing the initial embryo to remove part of the adhesive, form a gap inside the dewaxed semi-finished product and then perform thermal dewaxing. The temperature of the thermal dewaxing is between 140°C and Between 170℃. Sintering the dewaxed semi-finished product causes the metal particles to fuse into a metal body and the graphene molecules form a three-dimensional network to be incorporated into the metal body.

In the method for manufacturing a graphene metal composite material of the present invention, the primary embryo includes the metal particles and the graphene microplates uniformly mixed, and each graphene microplate is coated with a solid adhesive to bond the metal particles .

In the manufacturing method of the graphene metal composite material of the present invention, the solvent is dewaxed and the initial embryo is immersed in a solution to dissolve the adhesive.

In the method for manufacturing the graphene metal composite material of the present invention, the thermal dewaxing heats the initial embryo to vaporize the adhesive.

In the method for manufacturing a graphene metal composite material of the present invention, the metal body is aluminum or copper.

In the method for manufacturing a graphene metal composite material of the present invention, the functional group is an oxygen-containing functional group. The functional group is stearic acid.

In the method for manufacturing a graphene metal composite material of the present invention, the adhesive contains 0.5 to 2% by weight of a coupling agent, and the coupling agent is a titanate or an organic chromium compound.

In the method for manufacturing a graphene metal composite material of the present invention, the adhesive contains 5 to 20% by weight of a dispersant, and the dispersant is methylpentanol, polyacrylamide, or fatty acid polyethylene glycol ester.

In summary, the manufacturing method of the graphene metal composite material of the present invention adds graphene when the metal powder and the binder are mixed, and forms a mixture of the metal, the binder and the graphene after mixing and granulation. After the wax, the metal powder is combined with graphene at the sintering stage to increase its heat transfer coefficient.

Referring to FIGS. 1 to 6, a preferred embodiment of the present invention provides a graphene metal composite material and a manufacturing method thereof. In this embodiment, the manufacturing method of the graphene metal composite material of the present invention includes at least the following steps:

In step a, a metal powder, a graphene powder and an adhesive 300 (binder) are provided, wherein the metal powder is aluminum powder or copper powder. The metal powder includes a plurality of metal particles 100 (aluminum particles or copper particles), the graphene powder includes a plurality of graphene microplatelets 200, and each of the graphene microplatelets 200 includes a plurality of graphene molecules connected as shown in FIG. Referring to FIG. 1, FIG. 7 and FIG. 8, graphene microchips (as shown in FIG. 7) are modified with functional groups to become functionalized graphene (as shown in FIG. 8). In this embodiment, the functional group is preferably an oxygen-containing functional group, such as stearic acid. The oxygen-containing functional group bonds one of the carbon atoms of graphene with a trivalent bond (SP3). Each graphene molecule includes six carbon atoms connected in a ring. As shown in FIG. 8, one of the carbon atoms in each graphene molecule is connected to a functional group by a three-covalent bond. The adhesive 300 is mainly a wax material which contains paraffin wax, microcrystalline wax or acrylic wax, etc., and is usually composed of a low molecular weight thermoplastic polymer or oil. The adhesive 300 contains 0.5-2% by weight of titanate or organic chromium compound as a coupling agent for fixing the wax material. The adhesive 300 contains a dispersing agent with a weight percentage of 5-20% so that the wax material can be uniformly dispersed. The dispersing agent may be methylpentanol, polyacrylamide or fatty acid polyethylene glycol ester.

In step b, the metal powder, graphene powder and adhesive 300 provided in step a are mixed and granulated to become a powder raw material 10. The kneading and granulation system uniformly mixes the metal powder, the graphene powder and the adhesive 300, so that the metal particles 100 and the graphene microchips 200 in the powder raw material 10 can be dispersed in the dispersant and coated with the adhesive 300, respectively. The functionalized graphene improves the dispersibility of the graphene microchip 200 in the metal powder and the adhesive 300 in step b. Because a certain amount of functional groups enter the graphene microchips 200, the graphene microchips 200 have the same kind of charge. When the graphene microchips 200 have functional groups, electrostatic repulsion will occur between the same kind of charges, making the graphene microchips 200 mutually It can be dispersed in the dispersant and adhesive 300 uniformly by repelling and separating. During the kneading process in step b, the functionalized graphene microplate 200 friction generates heat energy to cause the triple covalent bond of the oxygen-containing functional group to endothermically break, and the oxygen-containing functional group is separated. Therefore, the carbon atoms originally bonded by the oxygen-containing functional group can be immediately re-bonded to the three covalent bonds broken by the carbon atoms in the other graphene microplates graphene microplates 200, thereby making the graphene microplates 200 connected to a plane The metal particles 100 are covered in layers to form a sphere, and it is preferably 10 layers or less.

In step c, following step b, the powder raw material 10 is heated to melt into a liquid mixed raw material 20; the liquid mixed raw material 20 includes metal powder, liquid adhesive 300 and graphene powder,

In step d, following step c, the liquid mixed raw material 20 is injected into a mold 400 for injection molding and solidified into a green part 30 (green part); the green part 30 includes uniformly mixed metal particles 100 and graphene microchips 200, Each graphene microchip 200 is coated with a solid adhesive 300 to bond the metal particles 100.

In step e, following step d, the primary embryo 30 is subjected to a debinding process to remove the adhesive 300 in the primary embryo 30 to form a dewaxed semi-finished product 40 (brown part). The dewaxing method can be thermal debinding or watery/solvent debinding. The thermal dewaxing system heat-treats the initial embryo 30, uses an inert gas as a flowing medium, and heats up to crack and vaporize the adhesive 300 and bring it out of the medium. Vacuum dewaxing system uses high temperature and high vacuum to evaporate the adhesive 300, and then bring it out through distillation molecules. The solvent dewaxing system uses a solvent to dissolve the adhesive 300. Among them, the thermal dewaxing and solvent dewaxing can be carried out in parallel. First, the initial embryo 30 is solvent dewaxed out of the adhesive 300 to form a gap in the dewaxed semi-finished product 40 before thermal dewaxing, so it is conducive to the passage of high temperature gas through the gap The remaining adhesive 300 is decomposed and discharged. In step e, the temperature of the thermal dewaxing step is preferably lower than the melting point of the metal particles 100 and higher than the melting point or boiling point of the adhesive 300, and the environment is heated to 140°C to 170°C, because the graphene microchip 200 does not melt And the boiling point is much higher than the metal particles 100 and the adhesive 300, so the structure will not be destroyed during heat treatment.

In step f, following step e, the semi-finished product 40 is sintered and dewaxed to melt the metal particles 100 and combine with each other to form a metal body 100a. When the metal particles 100 are copper, the ambient operating temperature is heated to 1050°C for 1 hour to sinter the metal particles 100 For aluminum, the ambient operating temperature is heated to 600°C and sintered for 1 hour. Since the graphene microchip 200 is not melted and its boiling point is much higher than that of the metal particles 100 and the adhesive 300, the structure will not be destroyed during heat treatment, and the graphene microchip 200 is evenly distributed in the metal body 100a. The metal body 100a is aluminum or copper. In this way, the finished product 50 of the graphene metal composite material of the present invention is made.

Referring to FIG. 6, the finished graphene metal composite material 50 of the present invention is manufactured by the aforementioned manufacturing method. The graphene metal composite material of the present invention includes a metal body 100 a and a plurality of graphene microchips embedded in the metal body 100 a 200. The metal body 100a is aluminum or copper, and the graphene microchips 200 are evenly distributed in the metal body 100a.

In summary, the manufacturing method of the graphene metal composite material of the present invention adds graphene powder when the metal powder is mixed with the adhesive 300, and forms metal particles 100, graphene microchips 200 and adhesive 300 after mixing and granulation After injection molding and dewaxing, the graphene microchips 200 in the finished product 50 which are originally arranged in a spherical shape and coated with the metal particles 100 in the sintering stage form a three-dimensional network of connected spheres and are integrated into the metal body 100a , Improve the heat transfer coefficient of the finished product 50. By increasing the heat transfer coefficient of metal parts through graphene, compared with pure metal as a heat conduction medium, the present invention can configure a smaller graphene metal composite material as a heat conduction medium under the same total heat conduction. Furthermore, by adding functional groups in the present invention, the graphene microchips 200 are arranged in a more regular manner. Compared with the old Sui machine dispersion structure, the heat energy is dispersed more uniformly and thus has more excellent heat conduction efficiency.

The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Other equivalent changes using the patent spirit of the present invention should all fall within the patent scope of the present invention.

10‧‧‧ powder raw materials

20‧‧‧Liquid mixed raw materials

30‧‧‧Early embryo

40‧‧‧Dewaxed semi-finished products

50‧‧‧Finished

100‧‧‧Metal particles

100a‧‧‧Metal body

200‧‧‧Graphene microchips

300‧‧‧adhesive

400‧‧‧Mould

a~f‧‧‧step

FIG. 1 is a flowchart of a method for manufacturing a graphene metal composite material according to a preferred embodiment of the present invention.

2 is a schematic diagram of powder raw materials in a method for manufacturing a graphene metal composite material according to a preferred embodiment of the present invention.

FIG. 3 is a schematic diagram of the injection molding steps in the method for manufacturing the graphene metal composite material according to the preferred embodiment of the present invention.

4 is a schematic diagram of a preliminary embryo in the method for manufacturing a graphene metal composite material according to a preferred embodiment of the present invention.

5 is a schematic diagram of a dewaxed semi-finished product in the method for manufacturing a graphene metal composite material according to a preferred embodiment of the present invention.

6 is a schematic diagram of a graphene metal composite material according to a preferred embodiment of the present invention.

7 is a schematic diagram of graphene.

Figure 8 is a schematic diagram of functionalized graphene.

a~f‧‧‧step

Claims (9)

A method for manufacturing graphene metal composite material, including: a) Provide a metal powder, a graphene powder and an adhesive, wherein the metal powder includes a plurality of metal particles, the adhesive includes a wax material, the graphene powder includes a plurality of graphene microplates, and each of the graphene microplates includes A plurality of connected graphene molecules, each graphene molecule includes six carbon atoms connected in a ring, one of the carbon atoms in each graphene molecule is connected to a functional group by a three covalent bond; b) The metal powder, the graphene powder and the adhesive are mixed as a powder raw material, and the mixed friction generates heat to break the three covalent bonds of each functional group after absorbing heat, and the functional groups are separated from the graphene molecules. After the separation, each of the graphene molecules is bonded to the other graphene molecules through the broken three covalent bonds, so that the graphene molecules coat the metal particles; c) heating the powder raw material to melt into a liquid mixed raw material, the liquid mixed raw material including the metal powder, the liquid binder and the graphene powder; d) Inject the liquid mixed raw material into a mold for injection molding and solidify into an initial embryo; e) Remove the adhesive in the primary embryo to form a dewaxed semi-finished product, first perform solvent dewaxing on the primary embryo to remove part of the adhesive, form a gap inside the dewaxed semi-finished product and then perform thermal dewaxing, the temperature of thermal dewaxing Between 140°C and 170°C; and f) Sintering the dewaxed semi-finished product causes the metal particles to fuse into a metal body and the graphene molecules form a three-dimensional network to be incorporated into the metal body. The method for manufacturing a graphene metal composite material according to claim 1, wherein in step d, the primary embryo comprises the metal particles and the graphene microplates uniformly mixed, each of the graphene microplates is solid The adhesive coats and bonds the metal particles. The method for manufacturing a graphene metal composite material according to claim 1, wherein in step e, the solvent is dewaxed and the primary embryo is immersed in a solution to dissolve the adhesive. The method for manufacturing a graphene metal composite material according to claim 1, wherein in step e, the thermal dewaxing heat treats the primary embryo to vaporize the adhesive. The method for manufacturing a graphene metal composite material according to claim 4, wherein the metal body is aluminum or copper. The method for manufacturing a graphene metal composite material according to claim 1, wherein the functional group is an oxygen-containing functional group. The method for manufacturing a graphene metal composite material according to claim 6, wherein the functional group is stearic acid. The method for manufacturing a graphene metal composite material according to claim 1, wherein the adhesive contains 0.5 to 2% by weight of a coupling agent, and the coupling agent is a titanate or an organic chromium compound. The method for manufacturing a graphene metal composite material according to claim 1, wherein the adhesive contains 5 to 20% by weight of a dispersant, and the dispersant is methylpentanol, polyacrylamide or fatty acid polyethylene glycol ester.

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