KR20140125033A - Metal composite material comprising carbon coated nano metal particles and method thereof - Google Patents

Abstract

Disclosed are a metallic matrix composite containing nanometal particles coated with carbon, and a method for manufacturing the same. According to an embodiment of the present invention, the metallic matrix composite comprises: mixture composite particles in which nanometal particles coated with a carbon material is embedded in the surface of a high polymer binder; and a metallic matrix where the mixture composite particles are dispersed. The carbon material is a carbon nanotube, a carbon nanoplate, carbide or graphene nanoplatelet.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a metal composite material containing carbon-coated nano-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal composite material and a method of manufacturing the metal composite material, and more particularly, to a metal composite material including nano metal particles coated with carbon on a surface thereof and a manufacturing method thereof.

Graphene, a carbon isotope, is a carbon monoatomic layer with a hexagonal honeycomb shape. Such graphene has excellent physical properties such as a Young's modulus of 1 TPa and a fracture strength of 125 GPa. Thus, graphene-based metal composite materials have been studied extensively.

In forming a graphene-based metal composite material, attempts have been made to coat graphene or the like on the surface of nano-metal particles. Generally, CVD (Chemical Vapor Deposition) method is widely used.

However, in such conventional methods, there has been a problem that the cost increases due to a high manufacturing cost accompanied by the CVD method and a complicated process. Second, in order to improve the compatibility between the surface of the nano metal particles and the carbon material, Third, there is a problem in that particles of carbon nanotubes, graphenes, carbon nano plates, etc. have a very low density compared to metal particles, resulting in phase separation. In addition, since the carbon material is often broken down during dispersion, the physical properties of the metal composite material are deteriorated.

Therefore, there is a demand for a metal composite material and a manufacturing method that do not involve the above-described problems.

In the embodiments of the present invention, it is intended to provide a metal composite material having a high density due to uniform dispersion of a carbon material and having excellent physical properties such as yield strength and tensile strength.

Also, it is intended to provide a manufacturing method which can mass-produce the metal composite material and the metal composite molding including the metal composite material by a simple process.

According to an aspect of the present invention, there is provided a composite material comprising composite composite particles in which nano metal particles coated with a carbon material are embedded on a surface of a polymeric binder, and a metal matrix in which the hybrid composite particles are dispersed, Tube, carbon nano plate, carbide or graphene nano platelet may be provided.

At this time, the nano metal particles may be Al, Cu, Ni, Sn, W, Cr, Fe, or an alloy thereof.

According to another aspect of the present invention, there is provided a method for manufacturing a nano-metal particle, comprising: (1) preparing a nano-metal particle having a core-shall structure in which a carbon material is coated on a surface using an electric explosion method; A second step of preparing a hybrid composite particle by hybridizing the nano metal particles with a polymer binder; And a step of dispersing the hybrid composite particles in a metal matrix may be provided.

In this case, the carbon material may be a carbon nanotube, a carbon nanoplate, a carbide or a graphene nanoflourette, and the nano metal particles may be Al, Cu, Ni, Sn, W, Cr, Fe, The binder is selected from the group consisting of polyethylene, polypropylene, atatic polypropylene (APP), ethylene vinyl acetate, ethylene acrylate copolymer, polystyrene, cellulose resin, polyamide resin, polyacrylic acid, polyacrylic acid ester, polymethacrylic acid And poly (methacrylic acid) ester.

According to still another aspect of the present invention, there is provided a method for manufacturing a metal composite molding, which comprises molding a metal composite material produced by the above-described method for manufacturing a metal composite material through casting, rolling, or metal injection molding (MIM) A method can be provided.

At this time, the metal powder injection molding method includes a step of charging the metal composite material, the metal powder, the polymer binder, and the wax into a metal injection molding machine and performing an injection molding, and the wax is a paraffin wax, microcrystalline wax, stearic acid, Amide, and fatty acid alcohol ester.

Embodiments of the present invention can improve the compactness and the yield strength and the tensile strength of the metal composite material by uniformly dispersing the nano metal particles coated on the surface of the carbon material in the metal matrix.

In addition, it is possible to produce a large number of nano-metal particles coated with a carbon material on the surface thereof by using an electric explosion method, and by uniformly dispersing the nano metal particles on a metal matrix, the metal composite molding can be manufactured by a simpler method .

1 is a view schematically showing a metal composite material according to an embodiment of the present invention.
Fig. 2 is a view schematically showing hybrid composite particles in the metal composite material of Fig. 1; Fig.
3 is an SEM image of the hybrid composite particle of Fig.
4 is a flowchart of a method of manufacturing a metal composite material and a method of manufacturing a metal composite molding according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view of a metal composite material 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing hybrid composite particles 10 in the metal composite material 100 of FIG. 1 to be.

1, a metal composite material 100 includes hybrid composite particles 10 in which nano metal particles 12 coated with a carbon material 13 are embedded on a surface of a polymeric binder 11, 10 are dispersed in the metal matrix 20.

The hybrid composite particle 10 comprises a polymer binder 11 and nanometer-metal particles 12 embedded on the surface of the polymer binder 11. The hybrid composite particles 10 are formed by hybridization of the polymeric binder 11 and the nano-metal particles 12, and the hybrid composite process will be described later in the description of the production process. On the other hand, 'embedded' means that a part of the nano metal particles 12 is embedded in the surface of the polymeric binder 11 (see FIG. 2). 3, an SEM (Scanning Electron Microscope) image of the hybrid composite particle 10 is shown.

The polymeric binder 11 may be selected from the group consisting of polyethylene, polypropylene, atatic polypropylene (APP), ethylene vinyl acetate, ethylene acrylate copolymer, polystyrene, cellulose resin, polyamide resin, polyacrylic acid, Polymethacrylic acid, polymethacrylic acid, polymethacrylic acid and polymethacrylic acid ester, and is not limited to the materials listed above. The polymeric binder 11 may be in the form of pellets or powder.

The nanometer-sized metal particles 12 have a core-shallh structure, nanoscale metal particles are positioned on the core, and a carbon material 13 is positioned on the shell.

The carbon material 13 can be, but is not limited to, a carbon nanotube, a carbon nanoplate, a carbide or a graphene nanoplate. Carbon nanotubes are nanoscale cylindrical carbon crystals. Carbon nanoplates are also called graphene nanosheets and consist of a plurality of graphene layers. These carbon nanoparticles are similar in properties to graphene, but are easier to manufacture and easier to control than graphene. The graphene nanofloulet is a graphene produced by separating from natural graphite or expanded graphite and is a material which improves the dispersibility by adjusting the mixing ratio of the carbon nanotube and the organic solution to improve the horizontal orientation . On the other hand, a method of forming the carbon material 13 on the surface of the nanometer-sized metal particles 12 will be described in the following section of the method for producing a metal composite material.

The nano metal particles 12 are nano-scale metal particles 10 made of metal such as Al (aluminum), Cu (copper), Ni (nickel), Sn (tin), W (tungsten) Fe (iron), or an alloy thereof. However, the present invention is not limited to those listed above, and most of the metal materials may correspond to the nano-metal particles 12.

The particle size of the nano metal particles 12 is not limited, and may be, for example, 30 nm to 500 nm. It is advantageous in that the metal can be formed even at a low temperature of 500 DEG C or less owing to the nanoscale particle size of the nano metal particles 12. [

The metal matrix 20 serves as a matrix in which the hybrid composite particles 10 are dispersed and is made of a metal such as Al, Cu, Ni, Sn, W, Cr (chromium), Fe (iron), or an alloy thereof, but is not limited thereto. That is, the metal matrix 20 may be the same metal as the nano-metal particles 12 of the hybrid composite particles 10, or may be a different metal.

The composite composite material 100 having the above structure is obtained by uniformly dispersing the composite composite particles 10 in which the nano metal particles 12 having the surface of the carbon material 13 coated on the surface thereof are embedded in the metal matrix 20 , The compactness is improved and the yield strength and tensile strength thereof are high. This will be supplemented by a test example to be described later.

Hereinafter, a method of manufacturing a metal composite material and a method of manufacturing a metal composite molding according to embodiments of the present invention will be described.

4 is a flowchart of a method of manufacturing a metal composite material and a method of manufacturing a metal composite molding according to an embodiment of the present invention.

Referring to FIG. 4, a method of fabricating a metal composite material includes a first step of preparing nano metal particles having a core shell structure in which a carbon material is coated on the surface using an electric explosion method, a step of hybridizing the nano metal particles with a polymer binder (hybridization) to prepare hybrid composite particles; and (3) dispersing the hybrid composite particles in a metal matrix.

Meanwhile, the method for manufacturing a metal composite molding includes molding the metal composite material produced by the metal composite material manufacturing method through casting, rolling or metal injection molding (MIN).

Hereinafter, each step will be described.

(1) Method for manufacturing a metal composite material: Step 1

Step 1 is a step of preparing nano metal particles having a core shell structure in which a carbon material is coated on the surface using an electric explosion method. Here, the carbon material and the nano-metal particles have already been described above, so redundant description will be omitted.

The electric explosion method has a merit that it is economical, mass-produced and commercialized compared with the conventional metal nano powder manufacturing method as a technique of pulverizing metal using momentary electric energy. Such an electric explosion method utilizes the phenomenon that a metal wire explodes in the form of fine particles or vapor when a high-density current passes through a metal wire. When a strong impact current is applied to a metal wire located between the two electrodes, As the temperature rises, the surface of the metal wire cools while the inside of the metal wire forms a droplet, and a discharge occurs between the droplets and is vaporized. At this time, the vaporized metal gas expands instantaneously when the pressure inside the metal wire reaches the threshold value, and the metal pumice and gas are ejected at high speed to form fine particles.

The electric explosion method can be carried out using a conventional electric explosion device. Specifically, a metal wire having a thickness of 0.1 to 1 mm and a length of about 10 cm is prepared, (Approximately 30 kV) by applying a high voltage and a large current to the metal wire.

At this time, the metal wire may be in the form of a wire made of Al (aluminum), Cu (copper), Ni (nickel), Sn (tin), W (tungsten), Cr . The carbon-containing gas may be, for example, a hydrocarbon gas. Specifically, methane, ethane, ethylene, propane, propylene, butane or butylene gas may be used singly or in combination of two or more. It is not. The inert gas may be a mixture of helium, neon, argon, and nitrogen gas, or may be a mixture of two or more thereof, but is not limited thereto.

When the carbon material is coated on the surface of the nano metal particles by using the electric explosion method, the metal wire can be continuously fed into the device, and it is advantageous in mass production through a simple process (Step S110).

(2) Method for producing hybrid composite particles: Step 2

Step 2 is a step of preparing hybrid composite particles by hybridizing the nano metal particles with a polymer binder. Since the types of the polymeric binders and the like have been described above, redundant description is omitted.

The hybrid composite particles may be produced using a hybrid complexing machine. Examples of the hybrid hybridization equipment include a super mixer, a hybridizer, and a cyclomixer. The polymer binder and the nano-metal particles can be mixed at a high speed by using the above-described devices, so that the nano-metal particles can be embedded on the surface of the polymeric binder.

In order to solve the above problems and to form a more uniform metal composite material, there is a problem in that the metal composite material according to the embodiments of the present invention The nano metal particles coated with the carbon material are dispersed in the polymer binder in a linear manner. That is, the surface of the polymeric binder (particle) is softened by high shear force and temperature control by high-speed rotation, and when the polymer binder and the carbon material-coated nano-metal particles collide with each other during high-speed rotation, And is embedded on the surface of the polymeric binder. In this case, since the nanomaterials coated with the carbon material collide with each other and the agglomerated particles are disassembled, a very uniform dispersion can be secured. Since the potential energy of the nano metal particles is very large, the polymer can be embedded in the polymer binder, thereby lowering the total energy and maintaining a stable dispersion state (S 120).

(3) Method for manufacturing a metal composite material: Step 2

Step 3 is a step of dispersing the hybrid composite particles prepared in Step 2 into a metal matrix to produce a metal composite material. Since the metal matrix has been described above, the redundant description will be omitted.

When the hybrid composite particles are dispersed in the metal matrix as described above, not only the mechanical properties of the metal composite material are improved due to the carbon material, but also the density of the metal composite material is improved due to uniform dispersion of the nano metal particles (S130).

(4) Method of manufacturing molded metal composite article

The metal composite material can be manufactured by molding the metal composite material produced by the method for manufacturing a metal composite material described in the above items (1) to (3). Such a metal composite molding can be used as components in the electric and electronic industries such as automobiles, aerospace, space, military, cameras, and mobile phones in which high rigidity materials are required.

In order to produce a metal composite molding, the metal composite material can be molded through casting, rolling or metal injection molding (MIM). Hereinafter, the case where the metal composite material is formed by metal powder injection molding will be mainly described.

The metal powder injection molding method refers to a method in which a metal powder is injected into a mold using an injection molding machine and molded, and then sintered to form a metal precision part. Such a metal powder injection molding method is advantageous in that it is possible to form a high-precision part having a thin and complicated shape as compared with a molding method using a general mold.

In order to produce the metal composite molding according to the metal powder injection molding method, the metal injection molding machine is provided with the above-mentioned metal composite material (manufactured by the method of manufacturing the metal composite material described in the above (1) to (3)), metal powder, wax, Can be charged.

Here, the wax improves the moldability and releasability and functions to easily remove the polymeric binder. The wax may be at least one selected from the group consisting of paraffin wax, microcrystalline wax, stearic acid, fatty acid amide, and fatty acid alcohol ester, but is not limited thereto.

As described above, the metal composite material, the metal powder and the wax are charged into a metal injection molding machine, injection-molded, and then sintered again to finally produce a metal composite molding (S140).

Hereinafter, the present invention will be described in further detail through a test example. However, it is apparent that the present invention is not limited to the following test examples.

Test Example

The metal composite moldings corresponding to Examples 1 to 4 were prepared as shown in Table 1 below. Specifically, an aluminum wire was charged into an electric explosion device to produce nano aluminum particles coated with carbon nanoplate on the surface by an electric explosion method. The composite nano-aluminum particles were prepared by using an ethylene vinyl acetate (EVA) binder and a super mixer, and the hybrid composite particles were mixed with spherical aluminum powder having a size of 15 mu m (spherical aluminum powder having a size of 10 mu m Powder) and stearic acid (wax), charged into a metal injection molding machine, and extruded at a pressure of about 150 DEG C and 400 MPa. Next, the binder was pyrolyzed and the remaining extrudate was sintered to finally produce a metal composite molding.

For comparison with the examples, metal moldings corresponding to Comparative Examples 1 and 2 were prepared as shown in [Table 1] below. In Comparative Examples 1 and 2, only the nano aluminum particles coated with the carbon nanoplate are different from each other in the Examples, so the description of the specific processes is omitted (in Comparative Example 2, Silicon powder).

Next, the tensile strength, the yield strength and the compactness of the above Examples 1 to 4 and Comparative Examples 1 and 2 were measured and shown in Table 1. Tensile strength and yield strength were measured through a tension test (using TO-102 equipment, Testwin Inc.). On the other hand, the measurement of the density was performed by calculating the ratio of the density of measurement of Examples / Comparative Examples to the theoretical density.

Composition and characteristics unit Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Binder (EVA) weight% 18 18 18 18 18 18 15 μm Al weight% 80 78 75 74 81 77 10 mu m Si weight% - - - 4 - 4 Carbon nanoplate coated nano aluminum particles weight% One 3 6 3 - - Wax (stearic acid) weight% One One One One One One Yield strength MPa 186 196 175 198 134 162 The tensile strength MPa 225 237 230 268 161 198 Compactness % 98% 99% 99% 99% 94% 95%

As can be seen from Table 1, in the case of the metal composite molding corresponding to Examples 1 to 4, the yield strength, the tensile strength and the tightness were both higher than those of the metal molds of Comparative Examples 1 and 2 have. That is, when a metal composite molding including carbon nanoplate coated nano aluminum particles is manufactured, it can be confirmed that a metal mold having a high rigidity can be manufactured compared with a general metal molding.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, many modifications and changes may be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims. The present invention can be variously modified and changed by those skilled in the art, and it is also within the scope of the present invention.

100: metal composite material
10: Hybrid composite particles
11: polymer binder
12: nano metal particles
13: Carbon material
20: metal matrix

Claims (7)

A hybrid composite particle in which nano metal particles coated with a carbon material are embedded on a surface of a polymeric binder; and a metal matrix in which the hybrid composite particles are dispersed,
Wherein the carbon material is a carbon nanotube, a carbon nanoplate, a carbide, or a graphene nanoflurry. The method according to claim 1,
Wherein the nano metal particles are Al, Cu, Ni, Sn, W, Cr, Fe, or an alloy thereof. A first step of preparing nano-metal particles having a core-shall structure in which a carbon material is coated on the surface using an electric explosion method;
A second step of preparing hybrid composite particles by hybridizing the nano metal particles with a polymer binder; And
And dispersing the hybrid composite particles in a metal matrix. The method of claim 3,
Wherein the carbon material is a carbon nanotube, a carbon nanoplate, a carbide or a graphene nanoplate, and the nano metal particles are Al, Cu, Ni, Sn, W, Cr, Fe or an alloy thereof. The method of claim 3,
The polymeric binder may be selected from the group consisting of polyethylene, polypropylene, atatic polypropylene (APP), ethylene vinyl acetate, ethylene acrylate copolymer, polystyrene, cellulose resin, polyamide resin, polyacrylic acid, And at least one member selected from the group consisting of acrylic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid, maleic acid and maleic acid. A method for manufacturing a metal composite molding comprising molding a metal composite material produced by the method of manufacturing a metal composite material according to any one of claims 3 to 5 through casting, rolling or Metal Injection Molding (MIM) Way. The method of claim 6,
Wherein the metal powder injection molding method comprises a step of charging the metal composite material, the metal powder, the polymer binder and the wax into a metal injection molding machine and performing injection molding,
Wherein the wax is at least one selected from the group consisting of paraffin wax, microcrystalline wax, stearic acid, fatty acid amide and fatty acid alcohol ester.

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