KR102324720B1 - Manufacturing method of Hydrogen functionalized Graphene-Metal composite casting materials - Google Patents

Abstract

The present invention relates to a method for producing a hydrogen-functionalized graphene-metal composite casting material. More specifically, the present invention relates to a method for producing a hydrogen-functionalized graphene-metal composite casting material, which strengthens a bonding force between graphene and metal by functionalizing hydrogen in a mixture of the graphene and the metal, minimizes the cohesion of graphene by improving the dispersion of graphene, and which enables easy mass production of a graphene-metal composite casting material by suppressing separation due to the difference in density between graphene and metal during casting. The method for producing a hydrogen-functionalized graphene-metal composite casting material according to the present invention comprises: a material preparation step of preparing a graphene powder and a metal powder; a blending step of preparing a mixed powder by mixing the graphene powder with the prepared metal powder; a mixing step of enlarging a contact area between the graphene powder and the metal powder in the mixed powder by putting the mixed powder prepared through the blending step into a mixer in an inert gas atmosphere and then mixing at a predetermined temperature for a predetermined time; and a hydrogen functionalizing step of putting the mixed powder that has gone through the mixing step into a hydrogen-functionalizing device having an internal temperature lower than the melting point of the metal powder, letting a mixed gas, in which an inert gas and a hydrogen gas are mixed at a predetermined volume ratio, flow for a predetermined time into the hydrogen-functionalizing device into which the mixed powder has been put, and rapidly cooling the mixed powder put into the hydrogen-functionalizing device.

Description

Manufacturing method of Hydrogen functionalized Graphene-Metal composite casting materials

The present invention relates to a method for manufacturing a hydrogen-functionalized graphene-metal composite cast material, and more particularly, to strengthen the bonding force between graphene and metal by functionalizing hydrogen in a mixture of graphene and metal, and dispersion of graphene It is possible to easily cast a large amount of graphene-metal alloy by minimizing the aggregation phenomenon of graphene by improving the degree of graphene and suppressing the separation phenomenon due to the difference in density between graphene and metal during casting using graphene and metal mixture. It relates to a method for producing a hydrogen-functionalized graphene-metal composite casting material.

In general, materials for aircraft and automobiles are increasingly required to be lightweight and high-strength for the purpose of improving fuel efficiency and reducing energy consumption, and many studies on composite materials to satisfy these requirements are being conducted.

In particular, among graphene-metal composites, graphene-aluminum composites are widely used as structural members of aircraft and automobiles due to their advantages such as light weight, high strength, and excellent formability.

Conventional graphene-metal composites are manufactured through a powder metallurgy process of mixing metal powder and graphene powder, milling it, and sintering it. In the case of powder metallurgy, graphene from graphene powder Due to the van der Waals force between the graphenes, it is difficult to distribute them uniformly in the metal matrix because the graphene has a property of strongly aggregating between them. The uniform distribution within the matrix is reduced.

In addition, the agglomerated graphene interferes with the sintering of the composite powder to reduce the density and reduce the properties of the composite material. There was a problem in that the reinforcement effect by the original graphene could not be expected by forming the graphene.

In the case of producing a graphene-metal composite using a conventional casting process, graphene is oxidized by reacting with air at 400° C. or higher, reacting with metal to produce carbide, or due to the density difference between graphene and metal. There was a problem in that it was difficult to manufacture a graphene-metal composite using a casting process due to the dispersion problem caused by the

Accordingly, Registered Patent No. 10-1453870 (Title of the invention: 'Method for manufacturing a metal-carbon composite using molten metal') and Patent Publication No. 10-2016-0050258 (Title of the invention: 'Graphene metal nanocomposite material and In the manufacturing method'), a metal and ceramic coating layer or a ceramic coating layer is formed on carbon or graphene particles to reduce the density difference between carbon or graphene and metal, and a metal and ceramic coating layer or ceramic coating layer Carbon or graphene particles in which the bay is formed are put into the molten metal together with the metal so that carbon or graphene-metal composites can be manufactured through the casting process,

In this case, in order to form a metal or ceramic coating layer on carbon or graphene particles, graphene is dispersed in a solvent, a ceramic salt is added and mixed, or the process is complicated and difficult because it is coated by an electroless plating method. In the case of forming a metal or ceramic coating layer on carbon or graphene to reduce the density difference with the metal, there is a problem in that it is difficult to match the same density value as the metal, and the density value due to the change in the thickness of the coating layer formed during the casting process, etc. This fluctuates, and a part of the graphene charged into the molten metal is discharged to the outside while vaporizing, so there is a problem in that it is difficult to uniformly mix with the metal matrix.

Registered Patent No. 10-1453870 (Title of the invention: 'Method for manufacturing a metal-carbon composite using molten metal') Patent Publication No. 10-2016-0050258 (Title of the invention: 'Graphene metal nanocomposite material and manufacturing method thereof')

The present invention was derived to solve the above problems, and functionalized hydrogen in a mixture of graphene and metal to strengthen the bonding force between graphene and metal, and to improve the dispersibility of graphene to minimize agglomeration,

In addition, in the casting process using the graphene and metal mixture, the separation phenomenon due to the density difference between the graphene and the metal is suppressed, so that the graphene-metal alloy can be easily manufactured in large quantities through the casting process.

In one aspect of the present invention for solving the above-mentioned problems, a material preparation step of preparing a graphene powder and a metal powder; a mixing step of preparing a mixed powder by mixing the graphene powder with the prepared metal powder; A mixing step of increasing the contact area between the graphene powder and the metal powder in the mixed powder by adding the mixed powder prepared through the mixing step to a mixer in an inert gas atmosphere, mixing at a predetermined temperature for a predetermined time; And, the mixed powder that has undergone the mixing step is put into a hydrogen-functionalized device having an internal temperature lower than the melting point of the metal powder, and an inert gas and hydrogen gas are introduced into the hydrogen-functionalized device into which the mixed powder is introduced. a hydrogen functionalization step of rapidly cooling the mixed powder injected into the hydrogen functionalization device after flowing the mixed gas mixed in a predetermined volume ratio for a predetermined time; It provides a method for producing a hydrogen-functionalized graphene-metal composite cast material, characterized in that it is formed by including.

The method for producing a hydrogen-functionalized graphene-metal composite cast material according to an aspect of the present invention includes a high-temperature heat treatment step of heating the mixed powder that has undergone the hydrogen-functionalized step into a heating vessel heated to a predetermined temperature and heating it for a predetermined time. ; It can be formed to further include,

Preferably, after the hydrogen functionalization step and before the high temperature heat treatment step, a high energy beam is irradiated to the mixed powder that has undergone the hydrogen functionalization step, and the mixed powder is heated to a predetermined temperature through irradiation of the high energy beam for a predetermined time. a hydrogen functionalization control step of controlling the amount of functionalized hydrogen in the mixed powder by heating while; It may be formed to further include.

The method for manufacturing a hydrogen-functionalized graphene-metal composite cast material according to the present invention enhances the bonding force between graphene and metal by functionalizing hydrogen in a mixture of graphene and metal, and improves the dispersion of graphene by improving the dispersion of graphene. agglomeration can be minimized,

In addition, in the casting process using the graphene and metal mixture, the separation phenomenon due to the density difference between the graphene and the metal is suppressed, so that the graphene-metal alloy can be easily manufactured in large quantities through the casting process.

1 is a process block diagram showing a method for producing a hydrogen-functionalized graphene-metal composite cast material according to the present invention step by step;
2a, 2b and 2c are graphene prepared through a material preparation step, a mixing step, a mixing step, a hydrogen functionalization step, and a high-temperature heat treatment step in the method for manufacturing a hydrogen-functionalized graphene-metal composite cast material according to the present invention. -SEM images of aluminum composite castings, SEM enlarged images and EDX analysis graphs;
3 is an SEM image of a graphene-aluminum composite cast material having a hydrogen content of less than 1% prepared through the high-temperature heat treatment step;
4 is an aluminum alloy specimen (hereinafter 'Specimen 1') using a graphene-aluminum composite cast material that has been subjected to a hydrogen functionalization step in the manufacturing method of the hydrogen-functionalized graphene-metal composite casting material according to the present invention, high temperature heat treatment step Tensile test result graph for each of an aluminum alloy specimen (hereinafter 'Specimen 2') and a pure aluminum specimen (hereinafter 'Specimen 3') using a graphene-aluminum composite cast material that has been roughed up to;
5 is an aluminum alloy specimen using a graphene-aluminum composite cast material having a hydrogen content of less than 1% that has been roughed up to the hydrogen functionalization control step in the method for manufacturing a hydrogen-functionalized graphene-metal composite cast material according to the present invention (hereinafter 'Specimen 4'), an aluminum alloy specimen using a graphene-aluminum composite cast material having a hydrogen content of less than 1% that has been subjected to a high temperature heat treatment step (hereinafter referred to as 'Specimen 5'), less than 3% hydrogen that has been subjected to a hydrogen functionalization control step An aluminum alloy specimen using a graphene-aluminum composite cast material having 'Specimen 7') and the main indices of tensile tests for each of the pure aluminum specimens ('Specimen 3'); and,
6 is a graph of the SEM image and EDX analysis result of the fracture surface after performing a tensile test on the specimen 2; am

Hereinafter, embodiments of the present invention in which the above object can be specifically realized will be described with reference to the accompanying drawings. In describing the present embodiments, the same names and reference numerals are used for the same components, and an additional description thereof will be omitted below.

1 is a process block diagram showing step by step a method of manufacturing a hydrogen-functionalized graphene-metal composite cast material according to the present invention, and FIGS. 2a, 2b and 2c are hydrogen-functionalized graphene-metal composite castings according to the present invention. In the method, the SEM image, the SEM enlarged image and the EDX analysis graph of the graphene-aluminum composite cast material manufactured through the material preparation step, the mixing step, the mixing step, the hydrogen functionalization step, and the high temperature heat treatment step, FIG. 3 is the high temperature It is an SEM image of a graphene-aluminum composite cast material with a hydrogen content of less than 1% manufactured through a heat treatment step.

In addition, FIG. 4 shows an aluminum alloy specimen ('Specimen 1') using a graphene-aluminum composite cast material that has been subjected to a hydrogen functionalization step in the manufacturing method of the hydrogen-functionalized graphene-metal composite casting material according to the present invention ('Specimen 1'), high-temperature heat treatment It is a graph of tensile test results for each of an aluminum alloy specimen ('Specimen 2') and a pure aluminum specimen ('Specimen 3') using a graphene-aluminum composite cast material that has been roughed up to the stage,

5 is an aluminum alloy specimen (' Specimen 4'), an aluminum alloy specimen using a graphene-aluminum composite cast material having a hydrogen content of less than 1%, which has been subjected to a high-temperature heat treatment step ('Specimen 5'), a hydrogen content of less than 3%, which has been subjected to a hydrogen functionalization control step An aluminum alloy specimen using a graphene-aluminum composite cast material with eggplant ('Specimen 6'), an aluminum alloy specimen using a graphene-aluminum composite cast material having a hydrogen content of less than 3% that has been roughed up to the high-temperature heat treatment step ('Specimen 7') ) and a tensile test for each of the pure aluminum specimens ('Specimen 3'), and FIG. 6 is a graph of the SEM image and EDX analysis result of the fracture surface after performing the tensile test on the specimen 2.

As shown in FIG. 1, the method for manufacturing a hydrogen-functionalized graphene-metal composite cast material according to the present invention largely includes a material preparation step, a mixing step of mixing the prepared material in a predetermined ratio, and uniformly mixing the mixed powder. It is formed including a mixing step of mixing, and a hydrogen functionalization step of functionalizing hydrogen by putting the mixed powder into a hydrogen functionalization device.

The material preparation step is a step of preparing graphene powder and metal powder used as a material to prepare a hydrogen-functionalized graphene-metal composite cast material, wherein the graphene powder is single-layer graphene, multi-layered graphene Conventional graphene having a layered structure such as graphene, functionalized graphene, and graphene oxide may be used. In addition, as the metal powder, a metal powder that can be hydrogen functionalized and has an easy casting process can be used, and at least one selected from the group consisting of castable single element metals, alloys, sulfides, and nitrides. It may be formed as a powder of a metal, and may be a metal powder containing at least one metal selected from the group consisting of iron, copper, aluminum, nickel, magnesium, and titanium, which are widely used as metals and alloys.

The mixing step is a step of preparing a mixed powder by mixing the graphene powder with the prepared metal powder, and homogenizing 30 parts by weight or less of the graphene powder (excluding 0) in 100 parts by weight of the prepared metal powder at room temperature After input to the machine, the homogenizer is operated at 100 to 3600 rpm for at least 1 hour to minimize the separation between the metal powder and the graphene powder due to the difference in density and mix so that the metal powder and the graphene powder can be uniformly mixed with each other will do

When the graphene powder mixed with 100 parts by weight of the metal powder is mixed in more than 30 parts by weight, compared to the excess amount of the graphene powder, it is not homogeneously mixed with the metal powder, and the molten metal and the molten metal during the casting process There is a problem in that only graphene powder is wasted due to poor mixing, and it is difficult to uniformly mix the metal powder and graphene powder below the lower limit of the mixing speed and operating time of the homogenizer, and when it is higher than the upper limit, the metal powder And there is a problem in that the mixing cost is significantly increased compared to the mixing rate of the graphene powder.

In the mixing step, the mixed powder in which the metal powder and the graphene powder are uniformly mixed through the mixing step is put into a mixer composed of an internal inert gas atmosphere, and then mixed at a predetermined temperature for a predetermined time to mix the mixed powder The contact area between the heavy graphene powder and the fine metal powder is increased.

Preferably, by using a milling device such as an attrition mill, a ball mill, or a jet mill as a mixer, the metal powder and the graphene powder are agglomerated together to form a metal powder and It makes it possible to increase the physical and mechanical contact area between graphene powders. In addition, the inside of the mixer is created in an inert gas atmosphere such as argon or nitrogen gas to prevent oxidation of the metal powder, and mixing is performed at 70 to 100° C. for 12 hours or more to perform a pretreatment process for hydrogen functionalization. let it do

Below the lower limit of the forming temperature and operating time inside the mixer, the contact intimacy between the graphene powder and the metal decreases, so that the physical and mechanical contact area between the metal powder and the graphene powder through van der Waals force is insufficient. If it is higher than the upper limit, the cost efficiency of the mixing process is lowered compared to the physical and mechanical contact area between the metal powder and the graphene powder.

In the hydrogen functionalization step, the mixed powder that has undergone the mixing step is put into a hydrogen functionalization device in which an internal temperature is formed at a predetermined temperature lower than the melting point of the metal powder, and into the hydrogen functionalized device into which the mixed powder is put, inert After flowing the mixed gas in which gas and hydrogen gas are mixed in a predetermined volume ratio for a predetermined time, the mixed powder injected into the hydrogen functionalizing device is rapidly cooled to functionalize hydrogen in the mixed powder.

In general, hydrogen functionalization is a form in which hydrogen or a functional group that can generate hydrogen is trapped by a known structure, and among the bonding of functional groups containing hydrogen, such as hydrogen bonding, covalent bonding containing hydrogen, van der Waals bonding, etc. It means that hydrogen is bonded or adsorbed to the matrix through one or more bonds.

In the method for manufacturing a hydrogen-functionalized graphene-metal composite casting material according to the present invention, as an embodiment of hydrogen functionalization of the graphene-metal mixed powder, first, argon or nitrogen gas, etc. for preventing oxidation of the metal powder While flowing the mixed gas mixed with 10 to 100 parts by volume of hydrogen gas to 100 parts by volume of the inert gas into the hydrogen functionalization device in which the mixed powder is added, the temperature inside the device is lower than the melting point of the metal powder to 300 to 800℃ 5 After maintaining for more than an hour, it is quenched to room temperature to perform hydrogen functionalization on the graphene-metal mixed powder.

The inert gas of the mixed gas prevents oxidation of the metal powder, the hydrogen gas contributes to the hydrogen functionalization of the mixed powder, and when there is oxygen in the hydrogen functionalization device, water is generated while reacting with the hydrogen gas is emitted as When the hydrogen gas mixed with 100 parts by volume of the inert gas is less than 10 parts by volume, hydrogen functionalization hardly occurs, and when the hydrogen gas is more than 100 parts by volume, there is a risk of explosion in the hydrogen functionalization device, and the mixed gas By continuously flowing into the hydrogen-functionalized device at a predetermined flow rate, the concentration of hydrogen gas inside the hydrogen-functionalized device is maintained so that hydrogen can be continuously functionalized in the mixed powder.

Most of the hydrogen functionalization of the graphene-metal mixed powder usually occurs in the graphene powder, and the hydrogen functionalization of the metal powder occurs at an almost insignificant level, and hydrogen helps the reduction of the graphene powder and removes oxygen. A high-purity graphene powder is formed, and other residues of the graphene powder are removed. Hydrogen bonds to the site where the oxygen and other residues are removed, forms a covalent bond between hydrogen and some graphene, and some hydrogen is trapped by the van der Waals force between the graphene layer and the layer. When cooled slowly in this state, some hydrogen bound to the graphene-metal mixed powder may be released to the outside, and the hydrogen-functionalized step of the method for producing a hydrogen-functionalized graphene-metal composite casting according to the present invention In the latter part of the process, a process of quenching to room temperature is provided to minimize the escape of hydrogen to the outside.

In the case of the graphene-metal composite cast material manufactured through the hydrogen functionalization step, most of the hydrogen functionalization occurs in the graphene powder, so that hydrogen is adsorbed or functionalized in a bonded state to the graphene powder, and the hydrogen functionalized in the graphene powder is cast By allowing the graphene to be mixed well and dissolved in the molten metal in the process, it is possible to easily manufacture a graphene-metal alloy through the casting process.

4 is a graphene-aluminum alloy and pure water prepared through a casting process by charging a graphene-aluminum composite cast material manufactured through the material preparation step, mixing step, mixing step, and the hydrogen functionalization step according to the present invention; A graph of a tensile test performed on each aluminum is shown, and as shown in FIG. 4 , graphene produced through a casting process by charging a graphene-aluminum composite cast material manufactured through the hydrogen functionalization step compared to pure aluminum - It can be seen that the tensile strength of the aluminum alloy is higher.

Preferably, the graphene-metal mixed powder, which has undergone the hydrogen functionalization step, is put into a heating vessel heated to a predetermined temperature, and a high-temperature heat treatment step of heating for a predetermined time can be performed to strengthen the bonding force between graphene and metal. be able to

In the high-temperature heat treatment step, the graphene-metal mixed powder that has undergone the hydrogen functionalization step is put into a heating vessel heated to 1000° C. or more, and the surface of the graphene-metal mixed powder is instantaneously exposed to a high temperature for several seconds to several minutes. As a process, at this time, the surface of the graphene-metal mixed powder heated to a high temperature instantaneously is exposed to some carbon-metal bonds as some functionalized hydrogen escapes, or carbon-oxygen through oxygen introduced from the outside. - By forming a metal bonding layer, the graphene-metal bond is strengthened, and a graphene coating layer is formed on the metal surface.

2 is an SEM image, an SEM enlarged image, and an EDX analysis graph of the graphene-aluminum composite cast material manufactured through the material preparation step, the mixing step, the mixing step, the hydrogen functionalization step, and the high-temperature heat treatment step according to the present invention; In 2a, the black background represents the bottom plate prepared for SEM imaging, and the bead shapes on the black background represent the grains of the graphene-aluminum composite cast material.

In addition, Fig. 2b is an enlarged SEM image of a part of Fig. 2a. Several spherical shapes indicate that graphene is coated like a gray cloud on the surface of the aluminum grains, and the irregular bar shapes on the upper left in Fig. 2b are the surface of the aluminum grains. It shows graphene not coated on, and the EDX analysis graph in FIG. 2c shows the analysis graph for the component in the portion shown in FIG. 2b, and it can be confirmed that graphene carbon is detected along with a large amount of aluminum.

Preferably, after the hydrogen functionalization step, before the high temperature heat treatment step, a high energy beam is irradiated to the mixed powder through the hydrogen functionalization step, and the mixed powder is heated to a predetermined temperature through the irradiation of the high energy beam for a predetermined time. It may further include a hydrogen functionalization control step of controlling the amount of hydrogen functionalized in the mixed powder by heating during the process.

According to the amount of hydrogen functionalized in the graphene-metal mixed powder through the hydrogen functionalization step, the material properties of the metal alloy such as tensile strength or strain of the metal alloy manufactured by charging the graphene-metal composite casting material during the casting process. In the method for producing a hydrogen-functionalized graphene-metal composite cast material according to the present invention, the amount of hydrogen functionalized in the graphene-metal composite cast material can be adjusted to a predetermined amount through the hydrogen functionalization control step. By doing so, the graphene-metal composite casting material is charged to control material properties such as tensile strength or strain rate of the metal alloy finally manufactured through casting and fixing.

The hydrogen functionalization control step is to control the amount of functionalized hydrogen by irradiating a high energy beam to the graphene-aluminum mixed powder in which hydrogen is functionalized through the hydrogen functionalization step, in which case the high energy beam can deliver energy. Preferably, an electron beam, an ion beam, and a microwave irradiation device among microwaves can be manufactured in a compact size, easy to operate, and economical microwave can be used. is 1000~3000 MHz, the output is 400~1500W, and it can be heated to 600~1200℃ by irradiating it to the mixed powder put in the reduction and resynthesis device, and the irradiation time is 5 seconds~10 minutes to control the amount of hydrogen it is preferable

Below the lower limit of the frequency, output, and heating temperature of the microwave, the amount of hydrogen released is small, so it is difficult to control the amount of hydrogen to be released, and above the upper limit of the frequency, output, and heating temperature of the microwave, There is a risk of explosion due to excessive heating, and there is a risk that the device may be damaged.

Through the irradiated high energy beam, the hydrogen-functionalized graphene-metal mixed powder self-heats and the temperature rises rapidly. In addition to the controllability, it is possible to increase the reactivity of the hydrogen-functionalized graphene-metal mixed powder through defects caused by the escape of hydrogen.

Hereinafter, Examples and Comparative Examples according to the present invention will be described.

In the method for producing a hydrogen-functionalized graphene-metal composite cast material according to the present invention, 100 parts by weight of pure aluminum powder and 3 parts by weight of graphene powder are prepared in the material preparation step, and the prepared pure aluminum powder and graphene powder are prepared After being put in the homogenizer, the mixing step was performed by operating at room temperature at a rotation speed of 300 rpm for 12 hours.

A ball mill device was used as a mixer, and the graphene-aluminum mixed powder that had undergone the mixing step was put into the mixer, and mixing was performed at 80° C. in an argon gas atmosphere for 24 hours.

After performing the mixing step, the mixed powder is put into the hydrogen functionalization device, and the mixed gas mixed with 100 parts of argon gas by 25 parts by volume of hydrogen gas is flowed into the device while the internal temperature is maintained at 550° C. for 5 hours After that, the hydrogen functionalization step was carried out by quenching to room temperature,

30 parts by weight of pure aluminum was added to 100 parts by weight of the graphene-aluminum composite cast material roughed up to the hydrogen functionalization step, stirred, and then solidified to prepare a specimen.

division C H N S content(%) 97.77 2.23 None None

Table 1 is a CHNS elemental analysis table for graphene powder in the graphene-aluminum composite cast material that has been subjected to the hydrogen functionalization step in Example 1, and, as shown in Table 1, functionalized on the carbon together with carbon You can check the hydrogen content.

In addition, the graphene-aluminum composite cast material that had undergone the hydrogen functionalization step was put into a heating vessel heated to 1200° C., heated for 20 seconds, and recovered to perform the high-temperature heat treatment step,

30 parts by weight of pure aluminum was added to 100 parts by weight of the molten graphene-aluminum composite cast material roughed up to the high-temperature heat treatment step, stirred, and then solidified to prepare a specimen.

2 is an SEM image, an SEM enlarged image, and an EDX analysis graph of the graphene-aluminum composite cast material manufactured through the material preparation step, the mixing step, the mixing step, the hydrogen functionalization step, and the high-temperature heat treatment step according to the present invention; In 2a, the grains of the graphene-aluminum composite cast material in the shape of beads can be confirmed on a black background, and FIG. 2b is an enlarged SEM image of a part of FIG. 2a. It can be seen that they are coated together,

In addition, graphene not coated on the surface of aluminum grains can be confirmed through the irregular bar shapes on the upper left in FIG. 2b , and graphene carbon is detected along with a large amount of aluminum through the EDX analysis graph in FIG. 2c . have.

In the method for producing a hydrogen-functionalized graphene-metal composite cast material according to the present invention, 100 parts by weight of pure aluminum powder and 3 parts by weight of graphene powder are prepared in the material preparation step, and the prepared pure aluminum powder and graphene powder are prepared After being put in the homogenizer, the mixing step was performed by operating at room temperature at a rotation speed of 300 rpm for 12 hours.

A ball mill device was used as a mixer, and the graphene-aluminum mixed powder that had undergone the mixing step was put into the mixer, and mixing was performed at 80° C. in an argon gas atmosphere for 24 hours.

After performing the mixing step, the mixed powder is put into the hydrogen functionalization device, and the mixed gas mixed with 100 parts of argon gas by 25 parts by volume of hydrogen gas is flowed into the device while the internal temperature is maintained at 550° C. for 5 hours After that, it was quenched to room temperature to carry out the hydrogen functionalization step.

The graphene-aluminum composite cast material that has undergone the hydrogen functionalization step is placed in a microwave irradiation device for the hydrogen functionalization control step, the frequency of the microwave is 2450 MHz, the output is 1100W, and irradiated for 60 seconds, less than 1% hydrogen A graphene-aluminum composite casting material having a content was prepared.

In this state, 30 parts by weight of pure aluminum was added to 100 parts by weight of the molten metal of the graphene-aluminum composite cast material in this state, stirred, and then solidified to prepare a specimen.

In addition, the graphene-aluminum composite cast material having a hydrogen content of less than 1% through the hydrogen functionalization control step is put into a heating vessel heated to 1200° C., then heated for 20 seconds and recovered to perform the high-temperature heat treatment step did,

30 parts by weight of pure aluminum was added to 100 parts by weight of the molten graphene-aluminum composite cast material roughed up to the high-temperature heat treatment step, stirred, and then solidified to prepare a specimen.

3 is an SEM image of a graphene-aluminum composite casting material having a hydrogen content of less than 1% prepared through the high-temperature heat treatment step, and as shown in FIG. 3, it can be confirmed that the graphene is coated on the surface of the spherical aluminum matrix. can

Example 2 and the material preparation step, the mixing step, the mixing step, and the hydrogen functionalization step are carried out in the same way, however, in the hydrogen functionalization control step after the hydrogen functionalization step, the graphene-aluminum composite casting material is A graphene-aluminum composite cast material having a hydrogen content of less than 3% was prepared by irradiating it for 10 seconds with a microwave frequency of 2450 MHz and an output of 400W, which was placed in a microwave irradiation device for the hydrogen functionalization control step. In a state of graphene-aluminum composite cast material, 30 parts by weight of pure aluminum was added to 100 parts by weight of molten metal, stirred, and then solidified to prepare a specimen.

In addition, the graphene-aluminum composite cast material having a hydrogen content of less than 3% through the hydrogen functionalization control step is put into a heating vessel heated to 1200° C., then heated for 20 seconds and recovered to perform the high temperature heat treatment step Then, 30 parts by weight of pure aluminum was added to 100 parts by weight of the graphene-aluminum composite casting material roughed up to the high-temperature heat treatment step, stirred and solidified to prepare a specimen.

[Comparative Example 1]

A specimen was prepared by casting 100 parts by weight of pure aluminum into the molten metal.

4 is an aluminum alloy specimen using the graphene-aluminum composite cast material roughed up to the hydrogen functionalization step in Example 1 ('Specimen 1'), and an aluminum alloy specimen using the graphene-aluminum composite cast material roughed up to the high temperature heat treatment step ( As a result of the tensile test for each of 'Specimen 2') and pure aluminum specimens ('Specimen 3'), it can be seen that the yield strength and modulus of Specimen 2 were significantly increased compared to Specimen 3, and Specimen 1 and Specimen 3 It can be seen that the yield strength and elastic modulus were increased compared to .

5 is an aluminum alloy specimen ('Specimen 4') using a graphene-aluminum composite cast material having a hydrogen content of less than 1% that has been roughed up to the hydrogen functionalization control step in Example 2 ('Specimen 4'), which is less than 1% rough until the high temperature heat treatment step An aluminum alloy specimen ('Specimen 5') using a graphene-aluminum composite cast material having a hydrogen content, a graphene-aluminum composite cast material having a hydrogen content of less than 3%, which was subjected to the hydrogen functionalization control step in Example 3 An aluminum alloy specimen used ('Specimen 6'), an aluminum alloy specimen using a graphene-aluminum composite cast material having a hydrogen content of less than 3%, which was rough until the high-temperature heat treatment step ('Specimen 7'), and a pure aluminum specimen ('Specimen As the main index of the tensile test for each of 3), it can be seen that in the case of Specimen 4, the yield strength and the modulus of elasticity were significantly increased, and in the case of Specimen 6, the elongation was high. It can be confirmed that even in the case of a composite cast material, it can be sufficiently used for manufacturing a graphene-aluminum alloy through a casting process.

6 is a SEM image and EDX analysis results of the fracture surface after performing a tensile test on the specimen 2, it can be confirmed that graphene present in the alloy.

Although some embodiments have been described above by way of example, it will be apparent to those skilled in the art that the present invention may be embodied in many different forms without departing from the spirit and scope thereof.

Accordingly, the above-described embodiments are to be regarded as illustrative and not restrictive, and all embodiments within the scope of the appended claims and their equivalents are included within the scope of the present invention.

Claims (3)

Material preparation step of preparing graphene powder and metal powder;
a mixing step of preparing a mixed powder by mixing the graphene powder with the prepared metal powder;
A mixing step of increasing the contact area between the graphene powder and the metal powder in the mixed powder by adding the mixed powder prepared through the mixing step to a mixer in an inert gas atmosphere, mixing at a predetermined temperature for a predetermined time; and,
The mixed powder that has undergone the mixing step is put into a hydrogen-functionalized device having an internal temperature lower than the melting point of the metal powder, and an inert gas and a hydrogen gas are added into the hydrogen-functionalized device into which the mixed powder is added in a predetermined volume ratio a hydrogen functionalization step of cooling the mixed powder injected into the hydrogen functionalization device after flowing the mixed gas mixed with the furnace for a predetermined time; is formed including

a heat treatment step of putting the mixed powder that has undergone the hydrogen functionalization step into a heating vessel heated to a predetermined temperature and heating for a predetermined time; formed by further comprising,

After the hydrogen functionalization step, before the heat treatment step,
Hydrogen functionalization control of irradiating an energy beam to the mixed powder that has undergone the hydrogen functionalization step, and heating the mixed powder to a predetermined temperature for a predetermined time through irradiation of the energy beam to adjust the amount of hydrogen functionalized in the mixed powder Steps; Hydrogen-functionalized graphene, characterized in that it further comprises a method for producing a metal composite casting. delete delete

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