JP2006328507A - Method for manufacturing carbon nano-composite metal material, method for manufacturing carbon nano-composite metal compact, and carbon nano-composite metal compact - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for manufacturing a carbon nano-composite metal material so as to orient a carbon nano-material, which saves energy, increases a yield of production and enhances surface hardness. <P>SOLUTION: An extrusion apparatus 59 is prepared which comprises a container 57 having a hole 56 and a ram 58. The manufacturing method comprises the steps of: in Figure (a), heating the container 57 to a predetermined temperature; accommodating a primary compact 55 in the container 57; pushing the ram 58 in a direction as shown by an open arrow; and in Figure (b), extruding the primary compact through the hole 56 to produce the carbon nano-composite metal material 60. Figure (c) shows an appearance of the carbon nano-composite metal material 60, which proves that the carbon nano-materials 11 are oriented in an extrusion direction on the surface 61. Thus manufactured composite material contains a sufficient amount of the carbon nano-materials 11 in the skin as well, and shows improved abrasion resistance. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a composite metal material composed of a carbon nanomaterial and a matrix metal material, and a manufacturing technique thereof.

  In recent years, special carbon fibers called carbon nanofibers have attracted attention as reinforcing materials, and their utilization methods have been proposed. The carbon nanofiber is formed by winding a sheet of carbon atoms arranged in a hexagonal network in a cylindrical shape, and has a diameter of 1.0 nm (nanometer) to 150 nm and is at a nano level. Called carbon nanotubes (hereinafter referred to as carbon nanomaterials). The length is several μm to 100 μm.

  Since this carbon nanomaterial is not only a reinforcing material but also a good heat conductive material, mixing with a matrix metal material can improve strength and heat conductivity.

Conventionally, a technique for orienting carbon nanomaterials for the purpose of increasing thermal conductivity in a composite metal material containing carbon nanomaterials is known (see, for example, Patent Document 1).
JP 2004-131758 A (FIG. 4)

Patent document 1 is demonstrated based on the following figure.
FIG. 10 is a diagram for explaining the basic principle of the prior art. 101 is a cooling drum, 102 is a groove formed in the cooling drum 101, 103 is a container, 104 is a melt, 105 is a solidified body, and 106 is a rolling roll. 107 are cutters.

Then, a melt 104 obtained by mixing carbon nanomaterial with molten aluminum is supplied from the container 103 to the groove 102 of the cooling drum 101 at a constant flow rate. The cooling drum 101 is rotated at a high speed such that the peripheral speed is higher than the flow velocity of the melt 104.
Then, the melt 104 is pulled out by the groove 102, and the carbon nanomaterial is oriented in the pulling direction by this pulling action. Since it is cooled at the same time, it solidifies into a solidified body 105.

The solidified body 105 is rolled with a rolling roll 106 and cut with a cutter 107, whereby a desired linear member 108 can be obtained.
According to paragraph [0017] first line of Patent Document 1, the thickness of the linear member 108 is 0.1 mm to 2.0 mm.
In the linear member 108, since the carbon nanomaterial included therein is oriented in the longitudinal direction, the thermal conductivity in the longitudinal direction is remarkably increased.

However, the technique of Patent Document 1 has the following problems.
First, in order to obtain the melt 104, it is necessary to heat aluminum to the melting point or higher, which consumes a large amount of heat energy.
Next, if the rotational speed of the cooling drum 101 is excessive, the melt 104 is torn off, and if the rotational speed of the cooling drum 101 is too low, the orientation of the carbon nanomaterial is reduced. Difficult and production yield may be reduced.

  Moreover, although the melt 104 is cooled and solidified by the cooling drum 101, the solidification proceeds from the surface to the center. When solidification proceeds from the surface to the center, different substances (here, carbon nanomaterials) tend to gather at the center. That is, the distribution of the carbon nanomaterial becomes non-uniform and the strength is reduced. In particular, since the surface of the carbon nanomaterial is insufficient, the hardness of the surface is lowered, and the wear resistance is lowered.

  That is, the technique of Patent Document 1 has room for improvement in terms of energy saving, production yield, and surface hardness.

  An object of the present invention is to provide a technique for producing a carbon nanocomposite metal material that can increase the production yield while saving energy and can increase the surface hardness in a technique for orienting carbon nanomaterials.

  The method for producing a carbon nanocomposite metal material according to claim 1 comprises preparing a metal-attached carbon nanomaterial having a metal containing an element that reacts with carbon to form a compound, and a matrix metal material; The step of mixing the metal-attached carbon nanomaterial and the matrix metal material, the step of obtaining a green compact by pressing the obtained mixture, and coating the green compact with a higher melting point than the matrix metal material A step of coating with a material, a step of heating the coated green compact to a temperature in the solid-liquid coexistence temperature region of the matrix metal material in a vacuum, an inert gas or a non-oxidizing gas atmosphere, and a heated coating compact A process of obtaining a primary molded body by pressurizing and plastically deforming the body, and a process of obtaining a carbon nanocomposite metal material by extruding the primary molded body. Characterized in that it comprises.

  In the method for producing a carbon nanocomposite metal material according to claim 2, the prepared metal-attached carbon nanomaterial is a mixture of the carbon nanomaterial and the carbide-forming metal, and the resulting mixture is placed in a vacuum furnace and subjected to high-temperature vacuum. It is obtained by evaporating the carbide-forming metal and attaching it to the surface of the carbon nanomaterial.

  In the method for producing a carbon nanocomposite metal material according to claim 3, the carbide-forming metal is Ti or Si.

  In the method for producing a carbon nanocomposite metal material according to claim 4, the shape of the matrix metal material is a chip.

  In the method for producing a carbon nanocomposite metal material according to claim 5, the metal constituting the matrix metal material is a low melting metal or a low melting alloy whose melting point does not exceed 700 ° C.

  In the method for producing a carbon nanocomposite metal material according to claim 6, the low melting point metal or low melting point alloy is Mg or Mg alloy.

  In the method for producing a carbon nanocomposite metal material according to claim 7, the coating material is Al or an Al alloy.

  The method for producing a carbon nanocomposite metal molded article according to claim 8 is formed by die-casting the carbon nanocomposite metal material produced by the method for producing a carbon nanocomposite metal material according to any one of claims 1 to 7. It is characterized in that a molded product is obtained.

  A carbon nanocomposite metal molded article according to a ninth aspect is obtained by the method for producing a composite metal molded article according to the eighth aspect.

  In the invention which concerns on Claim 1, the metal adhesion carbon nanomaterial to which the metal was adhered previously is used. Since the metal-attached carbon nanomaterial has higher wettability with the molten matrix metal material metal than the carbon nanomaterial, the carbon nanomaterial can be evenly dispersed in the molten matrix metal. Improvement in mechanical strength and the like can be easily realized by mixing the carbon nanomaterials more evenly.

  In claim 1, the carbon nanomaterial is oriented by extrusion. And in a heating process, a covering compacting body is heated to the temperature of a solid-liquid coexistence temperature range. That is, since the process of melting the material is not included in the series of processes, energy saving can be achieved.

  And in any of a preparatory process, a mixing process, a compacting process, a coating process, a heating process, a plastic deformation process, and an extrusion process, an advanced operation technique is unnecessary. Therefore, the production yield can be easily increased.

  Further, in the step of obtaining the primary molded body, the metal-rich liquid phase component is exuded from the matrix metal material by plastically deforming the coated green compact heated to a temperature in the solid-liquid coexistence temperature range, and this liquid phase Carbon nanomaterials can be dispersed in the components. As a result, the carbon nanomaterial can be evenly dispersed and the mechanical strength can be increased. In addition, since the carbon material of the skin does not move to the center in the subsequent steps, a sufficient amount of the carbon nanomaterial can be contained in the skin, and the wear resistance can be improved.

  Therefore, according to the first aspect of the present invention, in the technique for orienting the carbon nanomaterial, a production technique of the carbon nanocomposite metal material that can increase the production yield while improving energy and increase the mechanical strength and the surface hardness is provided. can do.

In the invention according to claim 2, the prepared metal-attached carbon nanomaterial is prepared by mixing the carbon nanomaterial and the carbide-forming metal, placing the obtained mixture in a vacuum furnace, and evaporating the carbide-forming metal under a high temperature vacuum. Adhere to the surface of the carbon nanomaterial.
Since the carbide-forming metal produces a compound with carbon, and this compound exhibits a bonding action, the carbide-forming metal can be firmly bonded to the carbon nanomaterial.

The invention according to claim 3 is characterized in that the carbide-forming metal is Ti or Si.
Both Si and Ti are metals having a melting point that can be deposited under vacuum, and also have good wettability with molten matrix metal. Since both Si and Ti are easily available, and especially Si is inexpensive, it is suitable for widely spreading the method of the present invention.

  In the invention according to claim 4, a chip is adopted as the matrix metal material. Since the chip is a mass, the surface area per mass is relatively small. On the other hand, a fine powder increases the surface area per mass. If powder is used for the matrix metal material, it is necessary to worry about surface oxidation and generation of oxidized sludge during heating. In this regard, since chips have much less surface oxidation than powder, there is no need to worry about oxidized sludge. As a result, a carbon nanocomposite metal material with high purity can be produced.

  In the invention which concerns on Claim 5, the metal which comprises a matrix metal raw material was made into the low melting metal or low melting-point alloy whose melting | fusing point does not exceed 700 degreeC. Since the carbon nanocomposite metal material obtained in the present invention can be melted at a relatively low temperature, it can be easily supplied to, for example, a die casting machine. Therefore, the use of the carbon nanocomposite metal material produced in the present invention can be expanded.

  In the invention according to claim 6, the low melting point metal or the low melting point alloy is Mg or Mg alloy. In this invention, since the compacting body is coat | covered at a coating process, Mg or Mg alloy which dislikes oxygen can also be processed. Mg or Mg alloy is a lightweight metal, and by including a carbon nanomaterial in this metal to increase mechanical strength, it is possible to provide a structural material that is lightweight and excellent in strength, thermal conductivity, and wear resistance. .

  The invention according to claim 7 is characterized in that the coating material is Al or an Al alloy. The matrix metal material is Mg or Mg alloy, and by covering the green compact with Al or Al alloy having a higher melting point than these, the coating action can be exerted even in the heating process, and there is a concern that oxidation will progress Absent. In addition, Al or Al alloy is a readily available general-purpose metal, and the manufacturing cost can be reduced.

The invention according to claim 8 is characterized in that a molded product is obtained by die-casting the carbon nanocomposite metal material produced by the carbon nanocomposite metal material production method according to any one of claims 1-7. And
In the carbon nanocomposite metal material produced by the method for producing a carbon nanocomposite metal material, the carbon nanomaterial is uniformly dispersed. In this way, the material in a uniform mixed state is supplied and die casting + is performed, so even a molded product with a complicated shape can be easily formed, and has high thermal conductivity, mechanical strength, and wear resistance. A composite metal molded product can be manufactured.

The invention according to claim 9 provides a carbon nanocomposite metal molded product obtained by the method for producing a composite metal molded product according to claim 8.
The carbon nanocomposite metal molded product according to the present invention has high mechanical strength and wear resistance because the carbon nanomaterial is uniformly dispersed, and high thermal conductivity because the carbon nanomaterial is oriented in the extrusion direction. There is an advantage.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is an explanatory view when a carbon nanomaterial is surface-treated for preparation according to the present invention.
(A): A carbon nanomaterial 11 is prepared. For example 10g.
(B): Si powder 12 is prepared. For example 1g.

(C): Carbon nanomaterial 11 and Si powder 12 are put in mortar 13 and mixed with pestle 14 for 15 to 30 minutes.
(D): The obtained mixture 15 is put in an alumina container 16 and covered with an alumina lid 17. The lid 17 employs a non-sealing lid, thereby allowing ventilation between the inside and the outside of the container 16.

  (E): A vacuum furnace 20 including a closed furnace body 21, heating means 22 for heating the inside of the furnace body 21, pedestals 23 and 23 on which the container 16 is placed, and a vacuum pump 24 for evacuating the inside of the furnace body 21. Prepare the container 16 in the vacuum furnace 20.

  Although the heating conditions and pressure conditions in the vacuum furnace 20 will be described with reference to the next figure, the Si powder in the mixture 15 evaporates by heating under vacuum. This vapor stirs the space formed by the container 16 and the lid 17 so as to foam. Such an action is called bubbling stirring. The carbon nanomaterial is unwound by this bubbling agitation, and Si vapor comes into contact with the surface of the unraveled carbon nanomaterial, forms a compound, and adheres as Si fine particles.

  To summarize FIG. 1, a step of mixing carbon nanomaterial 11 with metal powder 12 containing an element that reacts with carbon to form a compound, and the resulting mixture 15 is placed in a vacuum furnace 20, and metal under high temperature vacuum. A vapor deposition treatment step of evaporating the powder 12 and attaching the vapor to the surface of the carbon nanomaterial 11.

FIG. 2 is a graph of the furnace temperature and pressure in the furnace corresponding to Si. The horizontal axis represents time, and the vertical axis represents the furnace temperature and pressure in the furnace.
Start to 5:00: The furnace temperature is raised from room temperature to 300 ° C. over 5 hours at a vacuum degree of 6 × 10 ⁻³ Pa.

5:00 to 9:00: The furnace temperature is raised from 300 ° C. to 1400 ° C. over 4 hours at a vacuum degree of 5.3 × 10 ^{−3 to} 2.1 × 10 ⁻² Pa.
9 o'clock to 19 o'clock: Hold for 10 hours under conditions of a vacuum degree of 2.1 × 10 ⁻² Pa and 1400 ° C.

Since the melting point of Si is 1427 ° C., the temperature is maintained at a temperature just below the melting point (1350 to 1400 ° C.), and Si is maintained in a saturated vapor pressure state at this temperature. At 1350 ° C., the saturated vapor pressure is about 1.3 × 10 ⁻³ Pa, and at 1400 ° C., the saturated vapor pressure is about 2.1 × 10 ⁻² Pa. Since this degree of vacuum can be easily achieved in a vacuum furnace, the treatment temperature is suitably 1350 to 1400 ° C. However, 1350 ° C. has a low evaporation rate, and 1400 ° C. has a high evaporation rate.

  Next, SiC (silicon carbide) which is a compound of Si and carbon will be described. The standard free energy of formation of SiC is −39.6 kJ / mol at 1400 ° C., and this condition can be satisfied. Therefore, it is considered that Si vapor reacts with carbon of the carbon nanomaterial to become SiC.

Therefore, if the mixture is placed in a semi-sealed container and the Si powder is evaporated, bubbling agitation occurs, and Si fine particles can adhere to the carbon nanomaterial.
The long holding time of 10 hours was aimed at sufficient agitation and reaction. Of course, the holding time may be increased or decreased depending on conditions such as the mixing ratio and the processing amount.

After 19:00: Although the heating means is stopped, furnace cooling is performed while maintaining a vacuum degree of 1.1 × 10 ⁻³ Pa. Furnace cooling is a technique for cooling a product very gradually.

  FIG. 3 is an enlarged view of the metal-attached carbon nanomaterial produced by the method of the present invention. The metal-attached carbon nanomaterial 30 is uniformly attached to the carbon nanomaterial 11 that is not aggregated and the surface of the carbon nanomaterial 11. It consists of a large number of Si fine particles 31. As described above, these Si fine particles 31 are obtained by crystallizing Si, which is an element that reacts with carbon to form a compound.

  Furthermore, it is important that the Si fine particles 31 are attached to the carbon nanomaterial 11 through SiC which is a carbide. The carbon nanomaterial 11 itself has poor wettability. Therefore, there is a possibility that the bonding strength is insufficient if it is simple Si particles. In this respect, by attaching Si fine particles to the surface of the carbon nanomaterial 11, a SiC reaction layer is formed at the interface, and the Si fine particles 31 can be firmly attached to the carbon nanomaterial 11.

FIG. 4 is an explanatory view of a mixing step and a compacting step according to the present invention.
In (a), the metal-attached carbon nanomaterial 30 and the matrix metal material 32 produced by shaving from a metal lump are placed in a container 33 and sufficiently mixed with a rod 34. The matrix metal material 32 is, for example, an Mg alloy.

In (b), the mixture 35 obtained by sufficiently mixing is transferred to the aluminum can 36.
In (c), the aluminum can 36 is placed on the base 37 and surrounded by a die 38. Next, the punch 39 is advanced into the aluminum can 36 and the mixture 35 is pressed and hardened. The compacted product becomes a green compact 41.

FIG. 5 is an explanatory diagram of the heating process according to the present invention.
In (a), in order to protect the compacting body 41 from oxidation, it is covered with a metal material having a higher melting point than the matrix metal material (reference numeral 32 in FIG. 4 (a)). Specifically, if the matrix metal material is an Mg alloy, an aluminum material having a higher melting point is adopted as the coating material.

  That is, the part which protrudes from the compacting body 41 among the aluminum cans 36 is excised. Then, the aluminum thin plate 42 is placed on the upper surface. Thus, a coated compacted body in which the compacted compact 41 is coated with a metal material (aluminum can 36 + aluminum thin plate 42) having a melting point higher than that of the matrix metal material 32 can be obtained.

  In (b), when there is a possibility of oxidation of the coated green compact 43 after the next treatment, the non-oxidation tank 46 filled with argon gas from the argon container 45 is degassed by the vacuum device 44. In addition, the coated green compact 43 is stored. Argon gas is a kind of inert gas and exhibits an antioxidant effect.

In (c), the compacted powder compact 43 is placed in a heating furnace 48, and a non-oxidizing gas, for example, a mixed gas of carbon dioxide gas and sulfur hexafluoride gas (SF ₆ ) is introduced into the furnace from a gas blowing pipe 49. Infuse. And it heats to the temperature of the solid-liquid coexistence temperature range of a matrix metal raw material (FIG. 4 (a) code | symbol 32).

FIG. 6 is an explanatory diagram of the plastic deformation process according to the present invention. The plastic deformation can be performed by any of a rolling mill, a forging machine, and a press machine. An example in which the plastic deformation is performed by the press machine 50 will be described.
In (a), a press machine 50 comprising a base 51, a die 52 and a punch 53 is prepared, and the coated powder compact 43 is pressed down by this press machine 50. As a result, the height decreases and the diameter increases.
In (b), the aluminum can 36 and the aluminum thin plate 42 are removed from the coated green compact 43 whose height is reduced and the diameter is increased.

(C) shows the primary molded body 55 after the coating made of the aluminum can 36 and the aluminum thin plate 42 is peeled off.
In order to obtain the primary molded body 55, the coated metal powder compact heated to a temperature in the solid-liquid coexistence temperature region of the matrix metal material is plastically deformed, so that a metal-rich liquid phase component is oozed out of the matrix metal material, The carbon nanomaterial can be dispersed in this liquid phase component.

FIG. 7 is an explanatory view of an extrusion process according to the present invention.
In (a), an extrusion device 59 comprising a container 57 having a hole 56 and a ram 58 is prepared, the container 57 is heated to a predetermined temperature, and the primary molded body 55 is accommodated. Then, the ram 58 is extruded as indicated by the white arrow.
The carbon nanocomposite metal material 60 can be obtained by extruding from the hole 56 in (b).

(C) shows the appearance of the carbon nanocomposite metal material 60, and the carbon nanomaterial 11 oriented in the extrusion direction can be recognized on the surface 61.
A sufficient amount of the carbon nanomaterial 11 can also be contained in the skin, and the wear resistance can be improved.

  Although the drawing is omitted, when the cross section of the carbon nanocomposite metal material 60 is observed, the carbon nanomaterial 11 oriented in the extrusion direction can be recognized in the cross section. Therefore, the carbon nanomaterial 11 can be evenly dispersed and the mechanical strength can be increased.

  FIG. 8 is a principle diagram of die casting according to the present invention, and a metal forming apparatus 70 is prepared for performing die casting. In this metal forming apparatus 70, for example, a plunger 73 is accommodated in a heating cylinder 72 having a material supply port 71 so as to be reciprocally movable, the blanker 73 is driven by an injection cylinder 74, and a main part is covered with a cover 75. A die-cast machine-like device in which the tip of the heating cylinder 72 faces the fixed plate 78 is desirable. A fixed mold 79 is attached to the fixed plate 78 and a movable mold 82 is attached to the opposed movable plate 81 to form a cavity 83 between the molds 79 and 82.

  Then, the carbon nanocomposite metal material 60 shown in FIG. 7C is heated to a solid-liquid coexistence temperature to form a semi-molten material 84. Such a semi-molten material 84 is poured into the heating cylinder 72 from the material supply port 71 using the container 85 or an appropriate supply mechanism. Next, the semi-molten material 84 is injected into the cavity 83 by advancing the plunger 73.

FIG. 9 is a perspective view of a carbon nanocomposite metal molded product manufactured by the method of the present invention, and shows that a carbon nanocomposite metal molded product 86 having a complicated shape can be manufactured by the metal molding apparatus 70 of FIG. Show.
In the carbon nanocomposite metal material 60 produced by the method for producing a carbon nanocomposite metal material, the carbon nanomaterial is uniformly dispersed. In this way, a uniform mixed material is supplied and die casting is performed, so even a molded product with a complicated shape can be easily molded, and carbon with high thermal conductivity, mechanical strength and wear resistance. A nanocomposite metal shaped article 86 can be produced.

(Experimental example)
Experimental examples according to the present invention will be described below. Note that the present invention is not limited to experimental examples.
1. Metal-attached carbon nanomaterials used for testing:
1-1 Carbon nanomaterial:
A carbon nanofiber having a diameter of 1.0 nm (nanometer) to 150 nm × a length of several μm to 100 μm (hereinafter referred to as CNF). This CNF is applied to Comparative Examples 01 and 02. That is, Comparative Examples 01 and 02 are not subjected to the following 1-3 vacuum heat treatment. Proceed to
1-2 Carbide forming metal:
Si powder. 10% by mass of the carbon nanomaterial.
1-3 Vacuum heat treatment:
A metal-attached carbon nanomaterial (hereinafter referred to as SiCNF) was obtained by processing based on the furnace temperature curve and furnace pressure in FIG. This is applied to sample numbers 01, 02, and 04-06.

2. Matrix metal material used for testing:
Magnesium alloy die cast (JIS H 5303 MDC1D) chip (hereinafter referred to as MD1D)

3. Mixing process:
3-1: Mixing ratio Sample number 01: (SiCNF 5%) + (MD1D 95%)
Sample number 02: (SiCNF 5%) + (MD1D 95%)
Comparative Example 01: (CNF 10%) + (MD1D 90%)
Comparative Example 02: (CNF 10%) + (MD1D 90%)
Sample number 04: (SiCNF 10%) + (MD1D 90%)
Sample number 05: (SiCNF 15%) + (MD1D 85%)
Sample number 06: (SiCNF 15%) + (MD1D 85%)

4). Coating process:
Covering with aluminum can and aluminum foil

5. Heating process:
Heating temperature: 585 ° C
Heating time: 30 minutes Target solid phase ratio: about 40%

6). Plastic deformation process:
Press pressure: 100 MPa

7). Extrusion step: (applicable only to sample numbers 02, 04, 06 and comparative example 02)
Container temperature: 300 ° C
Extrusion ratio (inner cross-sectional area of container / area of hole) = 256: 16
Ram speed: 8mm / s or 16mm / s

8). result:
For test numbers 01, 02, 04-06, the thermal conductivity and compressive strength were measured. The details are shown in the following table.

Sample number 01 and sample number 02 are both 5% SiCNF and 95% MD1D test materials.
Regarding the thermal conductivity, the sample number 01 not subjected to the extrusion step remained at 40.1 W / m · K, whereas the sample number 02 after the extrusion step increased to 41.0 W / m · K.
As for the compressive strength, the sample number 01 that was not subjected to the extrusion step remained at 386 MPa, whereas the sample number 02 that passed through the extrusion step increased to 395 MPa.

Sample number 04 is a 10% SiCNF, 90% MD1D test material.
Regarding the thermal conductivity, Sample No. 04 that passed through the extrusion process rose to 42.4 W / m · K.
Also about the compressive strength, the sample number 04 which passed through the extrusion process rose to 402 MPa.

Sample number 05 and sample number 06 are both 15% SiCNF and 85% MD1D test materials.
Regarding the thermal conductivity, Sample No. 05 not subjected to the extrusion step remained at 43.3 W / m · K, whereas Sample No. 06 after the extrusion step increased to 55.1 W / m · K.
Regarding the compressive strength, Sample No. 05 not subjected to the extrusion step remained at 377 MPa, while Sample No. 06 after the extrusion step increased to 386 MPa.

  From the above results, increase in thermal conductivity and compressive strength was recognized by adding the extrusion process. These increases can be regarded as an effect due to the orientation of the carbon nanomaterial being achieved by the extrusion process.

Next, in order to evaluate the wear resistance performance, the amount of wear was measured.
Cylindrical test pieces having a diameter of 8 mm and a tip radius of 70 mm were prepared from Sample No. 04 and Comparative Examples 01 and 02, and these test pieces were pressed against a friction plate made of S45C carbon steel with a pressing force of 200 N. The reciprocation was performed under the conditions of a speed of 1 m / s and a sliding distance of 10,000 m.
Since a part of the cylindrical specimen was worn away, the amount of wear was calculated geometrically. The amount of wear is shown in the following table.

Comparative Example 01 and Comparative Example 02 are both 10% CNF and 90% MD1D test materials. Sample number 04 is a 10% SiCNF, 90% MD1D test material.
Regarding the amount of wear, Comparative Example 01 without the extrusion process is as large as 5 mm ³ . On the other hand, in Comparative Example 02 that has undergone the extrusion process, the wear amount is reduced to 4 mm ³ .
Furthermore, in the sample number 04 which performed the surface treatment and passed through the extrusion process, it is as small as 0.4 mm ³ . Since the wear resistance is higher as the wear amount is smaller, the wear resistance is improved by performing the extrusion process, and the wear resistance can be remarkably improved by performing the surface treatment.

  Although a detailed description is omitted, the same mechanical strength improvement effect could be obtained even when Si as a carbide forming metal (an element that reacts with metallic carbon to form a compound) is replaced with Ti. Furthermore, Zr (zirconium) and V (vanadium) can be employed in addition to Si and Ti as carbide formation.

  In addition to Mg and Mg alloys having a melting point of about 650 ° C., Al and Al alloys having a melting point of about 660 ° C., Sn and Sn alloys having a melting point of about 232 ° C., and a melting point of about 327 ° C. Pb and Pb alloy can be used, and the point is that the type is arbitrary as long as the melting point is a low melting point metal or low melting point alloy that does not exceed 700 ° C.

  The present invention is suitable for a composite metal material composed of a carbon nanomaterial and a matrix metal material.

It is explanatory drawing when surface-treating a carbon nanomaterial for the preparation which concerns on this invention. It is a graph of the furnace temperature and the furnace pressure corresponding to Si. It is an enlarged view of the metal adhesion carbon nanomaterial manufactured with the method of this invention. It is explanatory drawing of the mixing process and compacting process which concern on this invention. It is explanatory drawing of the heating process which concerns on this invention. It is explanatory drawing of the plastic deformation process which concerns on this invention. It is explanatory drawing of the extrusion process which concerns on this invention. It is a principle figure of die-casting concerning the present invention. It is a carbon nanocomposite metal molded product produced by the method of the present invention. It is a figure explaining the basic principle of the prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Carbon nanomaterial, 12 ... Carbide formation metal, 30 ... Metal adhesion carbon nanomaterial, 32 ... Matrix metal material, 35 ... Mixture, 41 ... Compacted compact, 43 ... Covered compact, 48 ... Heating furnace, DESCRIPTION OF SYMBOLS 50 ... Press machine, 55 ... Primary molded object, 59 ... Extrusion apparatus, 60 ... Carbon nano composite metal material, 70 ... Metal molding apparatus, 86 ... Carbon nano composite metal molded article.

Claims (9)

  Preparing a metal-attached carbon nanomaterial having a metal containing an element that reacts with carbon to form a compound, and a matrix metal material; and mixing the metal-attached carbon nanomaterial and the matrix metal material A step of obtaining a green compact by compacting the obtained mixture, a step of coating the green compact with a coating material having a melting point higher than that of the matrix metal material, and vacuuming the coated green compact. A step of heating to a temperature in the solid-liquid coexistence temperature region of the matrix metal material in an inert gas or non-oxidizing gas atmosphere, and pressurizing the heated coated powder compact to obtain a primary compact is obtained. A carbon nanocomposite metal material comprising a step and a step of obtaining a carbon nanocomposite metal material by extruding the primary compact Law.   The prepared metal-attached carbon nanomaterial is prepared by mixing the carbon nanomaterial and the carbide-forming metal, placing the resulting mixture in a vacuum furnace, evaporating the carbide-forming metal under a high temperature vacuum, and applying the carbon nanomaterial to the surface of the carbon nanomaterial. The method for producing a carbon nanocomposite metal material according to claim 1, wherein the carbon nanocomposite metal material is obtained by adhering.   The method for producing a carbon nanocomposite metal material according to claim 1 or 2, wherein the carbide-forming metal is Ti or Si.   4. The method for producing a carbon nanocomposite metal material according to claim 1, wherein the shape of the matrix metal material is a chip.   The metal constituting the matrix metal material is a low-melting-point metal or a low-melting-point alloy whose melting point does not exceed 700 ° C, manufacturing the carbon nanocomposite metal material according to any one of claims 1 to 4. Method.   The method for producing a carbon nanocomposite metal material according to claim 1, wherein the low melting point metal or low melting point alloy is Mg or Mg alloy.   The said coating material is Al or Al alloy, The manufacturing method of the carbon nano composite metal material of any one of Claims 1-6 characterized by the above-mentioned.   A carbon nanocomposite metal molded product obtained by die-casting a carbon nanocomposite metal material produced by the method for producing a carbon nanocomposite metal material according to any one of claims 1 to 7. Manufacturing method. A carbon nanocomposite metal molded product obtained by the method for producing a composite metal molded product according to claim 8.

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