JP2008184655A - Carbon fiber composite metal material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain the improvement of thermal conductivity and lightening in a carbon fiber composite metal material while securing its strength. <P>SOLUTION: In the carbon fiber composite metal material 1, first carbon fibers 3A and second carbon fibers 3B are arranged in a mother phase metal 2. The first carbon fibers 3A and the second carbon fibers 3B are arranged in the mother phase metal 2 in such a manner that the elongation direction of the fibers is made uniform in one direction. Further, the diameter of the first carbon fibers 3A is set so as to be larger than that of the second carbon fibers 3B. Each surface of the first carbon fibers 3A and second carbon fibers 3B is plated with a metal composing the mother phase metal 2, and thereafter, a plurality of the first carbon fibers 3A and second carbon fibers 3B whose surface is coated with the above metal, respectively are bundled, and are sintered. Thus, the carbon fiber composite metal material 1 can be obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a carbon fiber composite metal material constituted by arranging carbon fibers in a metal matrix.

  A heat transfer element that transfers heat from a high temperature portion to a low temperature portion is widely used for, for example, heat dissipation and temperature control of electricity and electronic equipment, heat dissipation and temperature control of home appliances, and the like. A heat transfer element used for such an application is required to have high thermal conductivity. In recent years, high thermal conductive composite materials using carbon fibers or carbon nanotubes have been proposed (for example, Patent Document 1). Patent Document 2 discloses a thick fiber layer in which a plurality of silicon carbide fibers having a diameter of 0.1 mm to 0.2 mm are arranged in parallel on the same plane, and a diameter in which an Al alloy is ion-plated on the surface. Sheet-like fine fiber layers formed by arranging a plurality of continuous carbon fibers of 0.005 mm to 0.015 mm in the same direction, alternately stacked in multiple layers via Al alloy foil, and hot-pressed A molded metal-based composite material is disclosed.

JP 2006-045596 A Japanese Patent No. 2639072

  By the way, in order to improve thermal conductivity with the high thermal conductive composite material disclosed in Patent Document 1 and to achieve weight reduction, the ratio (volume ratio) of the volume of carbon fiber or the like to the entire volume of the high thermal conductive material. It is necessary to improve. However, in the technique disclosed in Patent Document 1, when an attempt is made to improve the volume ratio of carbon fibers, voids and cracks are generated in the material, and the strength of the material itself is reduced. For this reason, it has been difficult to improve the volume ratio of carbon fibers and improve the thermal conductivity of the entire material. In addition, the technique disclosed in Patent Document 2 aims to obtain a lightweight, high-strength, high-rigidity metal-based composite material, but is not mentioned in terms of improving the thermal conductivity. There is room for improvement in improving the thermal conductivity.

  Therefore, the present invention has been made in view of the above, and an object of the present invention is to provide a carbon fiber composite metal material that can simultaneously achieve securing of strength, improvement of thermal conductivity, and weight reduction.

  In order to solve the above-described problems and achieve the object, a carbon fiber composite metal material according to the present invention is a pitch-based carbon having a higher thermal conductivity in the fiber elongation direction than the metal in the metal matrix. A plurality of fibers are arranged with the fiber extending direction aligned, and there are at least two types of diameters of the carbon fibers arranged in the matrix.

  In this carbon fiber composite metal material, a plurality of pitch-based carbon fibers whose thermal conductivity in the fiber extension direction is higher than that of the metal constituting the matrix phase are arranged in the metal matrix phase with the fiber extension direction aligned. In addition, the diameter of the carbon fiber is configured to have at least two kinds of sizes. As a result, the volume ratio of the carbon fiber to the carbon fiber composite metal material can be increased, so that securing of strength, improvement in thermal conductivity, and weight reduction can be achieved at the same time.

  Further, like the carbon fiber composite metal material according to the present invention, in the carbon fiber composite metal material, the carbon fiber has the largest diameter among the carbon fibers contained in the matrix and is elongated. A plurality of first carbon fibers arranged in the mother phase with the direction aligned, a plurality of first carbon fibers arranged in the mother phase with the first carbon fibers and fibers extending in the same direction, and the first carbon fiber And a second carbon fiber having a diameter smaller than that of the carbon fiber.

  Further, like the carbon fiber composite metal material according to the present invention, in the carbon fiber composite metal material, the second carbon fiber may be disposed between the first carbon fibers. preferable.

  Further, like the carbon fiber composite metal material according to the present invention, in the carbon fiber composite metal material, the volume ratio of the first carbon fiber to the other carbon fiber is 85:15 or more and 95: 5. The following is preferable.

  Further, as in the carbon fiber composite metal material according to the present invention, in the carbon fiber composite metal material, the diameter of the carbon fiber having a diameter smaller than that of the first carbon fiber is the diameter of the first carbon fiber. It is preferable to be 60% or more and 75% or less.

  Further, as in the carbon fiber composite metal material according to the present invention, in the carbon fiber composite metal material, the minimum gap between the first carbon fibers is 20% or more of the diameter of the first carbon fiber 30 or more. % Or less is preferable.

  Further, like the carbon fiber composite metal material according to the present invention, in the carbon fiber composite metal material, the carbon fiber is preferably a continuous fiber, and the length in the fiber extension direction is preferably aligned. .

  Further, like the carbon fiber composite metal material according to the present invention, in the carbon fiber composite metal material, the metal may be Cu, Al, Ag, Mg, W, Mo, Zn, or an alloy thereof. it can.

  Moreover, like the carbon fiber composite metal material according to the present invention, the volume ratio of the carbon fiber to the carbon fiber composite metal material is preferably 50% or more and 80% or less.

  Further, like the carbon fiber composite metal material according to the present invention, in the carbon fiber composite metal material, the carbon fibers coated with the metal of the matrix are bundled in a plurality with the fiber extension direction aligned, It can be compounded by pressure sintering.

  In the carbon fiber composite metal material according to the present invention, securing of strength, improvement in thermal conductivity, and weight reduction can be achieved at the same time.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the best mode for carrying out the invention (hereinafter referred to as an embodiment). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, or substantially the same, so-called equivalent ranges.

  The carbon fiber composite metal material according to the present embodiment is a carbon fiber composite metal material having a high thermal conductivity, and there are at least two kinds of diameters of carbon fibers arranged in the matrix of the metal, and A feature is that a plurality of the carbon fibers having higher thermal conductivity than the metal in the extending direction of the fibers (carbon fibers) (the length direction of the carbon fibers) are arranged in the matrix with the extending direction of the fibers aligned. There is.

  FIG. 1-1 is a perspective view showing a member made of the carbon fiber composite metal material of the present embodiment. FIG. 1-2 is a side view showing a member made of the carbon fiber composite metal material of the present embodiment. FIGS. 2-1 to 2-3 are schematic views illustrating the configuration of the carbon fiber composite metal material according to the present embodiment. FIGS. 2-1 to 2-3 are enlarged views of the AA cross section of FIG. 1-1. The carbon fiber composite metal material according to the present embodiment is a plane orthogonal to the fiber extension direction. The cross section when cut is shown. This carbon fiber composite metal material 1 is a so-called CFRM (Carbon Fiber Reinforced Metal). By arranging the carbon fiber in the metal matrix, the carbon fiber is superior in performance to the carbon fiber alone or the metal simple substance serving as the matrix. It is something to be demonstrated. In the carbon fiber composite metal material 1 according to the present embodiment, a higher thermal conductivity than that of a single metal as a parent phase is exhibited.

  As shown in FIGS. 1-1 and 1-2, in the member (carbon fiber composite metal member) 1B formed of the carbon fiber composite metal material 1 of the present embodiment, the carbon fiber CF is disposed in a metal matrix. Configured. The carbon fiber has an extremely large thermal conductivity in the direction of fiber extension than that in a direction orthogonal to the direction of fiber extension, and functions as a high heat conductive material in the direction of fiber extension. For this reason, the carbon fiber composite metal material 1 which concerns on this embodiment can be used as a heat-transfer element which conveys heat from a heat sink, a heat sink for heat dissipation, and a high temperature part to a low temperature part, for example.

  As shown in FIGS. 2-1 to 2-2, the carbon fiber composite metal material 1 according to the present embodiment includes first carbon fibers (hereinafter referred to as first carbon fibers) having different diameters in the matrix metal 2. ) 3A and a plurality of second carbon fibers (hereinafter referred to as second carbon fibers) 3B are arranged in a plurality with the fiber extending directions (directions indicated by arrows L in FIGS. 1-1 and 1-2) aligned. . Here, the diameter of the first carbon fiber 3 </ b> A is the largest among the plurality of carbon fibers having different diameters constituting the carbon fiber composite metal material 1 according to the present embodiment.

  In the carbon fiber composite metal material 1 according to the present embodiment, there are at least two types of diameters of the carbon fibers arranged in the matrix metal 2. In the carbon fiber composite metal material 1 shown in FIGS. 2-1 and 2-2, the diameter of the first carbon fiber 3A is larger than the diameter of the second carbon fiber 3B. That is, in the carbon fiber composite metal material 1 shown in FIG. 2A, there are two types of diameters of the carbon fibers in the matrix metal 2.

  In the present embodiment, the diameter of the carbon fiber is a nominal diameter of the carbon fiber, and it is assumed that the diameter is constant (including manufacturing variations and material variations) in the fiber elongation direction. That is, it is not premised on carbon fibers having a plurality of diameters exceeding the range of manufacturing variation and material variation with respect to the fiber elongation direction. Therefore, when there are a plurality of types in the diameter of the carbon fiber, it means that there are a plurality of carbon fibers having different diameters in the carbon fiber having a constant diameter in the fiber extension direction. That is, it does not mean that there are a plurality of diameters exceeding the range of manufacturing variation in the fiber elongation direction. The diameter of the carbon fiber is, for example, a center value (corresponding to the nominal diameter) ± 1 μm in consideration of manufacturing variations and material variations.

As the diameter of the carbon fiber, when the shape of the cross section perpendicular to the extending direction of the fiber is a circle, the diameter of the circle is adopted. When the cross-sectional shape cannot be called a circle, the equivalent diameter De defined by the equation (1) is used. Here, A in the formula (1) is a cross-sectional area of a cross section orthogonal to the fiber extending direction, and C is a circumferential length of the cross section orthogonal to the fiber extending direction.
De = 4 × A / C (1)

From Equation 1, in the case of a circle having a diameter a, De = 4 × π × a ² / (4 × π × a) = a, and the equivalent diameter is equal to the diameter of the circle. In the case of a square having a side length of b, De = 4 × b ² / (4 × b) = b, and the equivalent diameter is equal to the length of one side of the square. In the carbon fiber composite metal material 1 according to the present embodiment, in order to obtain the equivalent diameter of the carbon fiber, for example, the cross section when the carbon fiber composite metal material 1 is cut in a cross section orthogonal to the carbon fiber is enlarged, and the cross section It can be obtained from the image.

  In the carbon fiber composite metal material 1 shown in FIG. 2-3, a first carbon fiber 3A, a second carbon fiber 3B, and a third carbon fiber (hereinafter referred to as a third carbon fiber) 3C having different diameters are disposed ( The diameter of the first carbon fiber 3A> the diameter of the second carbon fiber 3B> and the diameter of the third carbon fiber 3C). That is, the carbon fiber composite metal material 1 shown in FIG. 2-3 has three types of diameters of carbon fibers arranged in the matrix metal 2. As described above, the carbon fiber composite metal material 1 according to the present embodiment needs to have at least two types of diameters of the carbon fibers arranged in the matrix metal 2. It is not limited to the kind or three kinds. However, considering the time and labor involved in manufacturing the carbon fiber composite metal material 1, the diameter of the carbon fiber disposed in the matrix metal 2 is preferably three or less, and the manufacturing difficulty and effects are taken into consideration. Then, two types are realistic.

  In the carbon fiber composite metal material 1 shown in FIG. 2A, one second carbon fiber 3B is arranged in a region surrounded by four adjacent first carbon fibers 3A. In the carbon fiber composite metal material 1 shown in FIG. 2B, one second carbon fiber 3B is disposed in a region surrounded by three adjacent first carbon fibers 3A.

  In the carbon fiber composite metal material 1 shown in FIGS. 2-1 and 2-2, the first carbon fiber 3 </ b> A and the second carbon fiber 3 </ b> B are regularly arranged in the matrix metal 2. In this embodiment, the diameter of the carbon fiber disposed in the matrix metal 2 only needs to have at least two sizes, and the first carbon fiber 3A and the second carbon fiber 3B having different diameters. And may be arranged irregularly. However, in order to increase the volume ratio of the carbon fibers in the carbon fiber composite metal material 1, a carbon fiber having a relatively small diameter is disposed in a region surrounded by the carbon fibers having a relatively large diameter in the matrix metal 2. Is preferably arranged.

  Next, the manufacturing procedure of the carbon fiber composite metal material 1 according to this embodiment will be described. In the following description, an example in which the first carbon fiber 3A and the second carbon fiber 3B having a smaller diameter than the first carbon fiber 3A are disposed on the matrix metal 2 will be described (see, for example, FIGS. 2-1 and 2-2). To do. That is, there are two types of diameters of carbon fibers arranged in the matrix metal 2. In the following description, please refer to FIGS. 1-1 to 2-2 as appropriate.

  FIG. 3 is a flowchart illustrating an example of a manufacturing procedure of the carbon fiber composite metal material according to the present embodiment. 4-8 is a schematic diagram for demonstrating the manufacturing procedure of the carbon fiber composite metal material which concerns on this embodiment. In manufacturing the carbon fiber composite metal material 1 according to the present embodiment, carbon fibers arranged in the matrix metal 2 are manufactured (step S101). As described above, there are at least two types of diameters of the carbon fibers included in the carbon fiber composite metal material 1 according to the present embodiment. For this reason, two types of carbon fibers (first carbon fiber 3A and second carbon fiber 3B) having different diameters are prepared.

  In the present embodiment, the first carbon fiber 3A having a diameter D1 of 5 μm or more and 30 μm or less can be used, a diameter D1 of 6 μm or more and 20 μm or less is preferable, and a diameter D1 of 7 μm or more and 10 μm or less is more preferable. The second carbon fiber 3B may have a diameter D2 of 3 μm to 20 μm, preferably a diameter D2 of 4 μm to 15 μm, and more preferably a diameter D2 of 5 μm to 8 μm. If it is such a range, the volume rate of carbon fiber can be improved, ensuring intensity | strength, and the improvement of the thermal conductivity and weight reduction of the carbon fiber composite metal material 1 can be achieved.

  Further, the diameter ratio D2 / D1 between the diameter D2 of the second carbon fiber 3B and the diameter D1 of the first carbon fiber 3A can be used when the diameter D1 is 0.5 to 0.9 μm, and is 0.55 to 0 .8 or less is preferable, and 0.6 or more and 0.75 or less is more preferable. If it is such a range, the volume rate of carbon fiber can be improved, ensuring intensity | strength, and the improvement of the thermal conductivity and weight reduction of the carbon fiber composite metal material 1 can be achieved.

  For example, as shown in FIG. 4, carbons having a plurality of types (two types in this embodiment) having different diameters prepared by mixing first carbon fibers 3A and second carbon fibers 3B having different diameters. A fiber group (3A + 3B) is obtained. Alternatively, when spinning a pre-carbonized fiber from a liquid crystalline mesophase pitch suitable for spinning obtained by heat treatment, filtration, hydrogenation, etc. of a coal tar-like pitch, a plurality of (in this embodiment, two types) ) To obtain a pre-carbonized fiber of diameter.

  As the first carbon fiber 3 </ b> A and the second carbon fiber 3 </ b> B used for the carbon fiber composite metal material 1 according to the present embodiment, those having higher thermal conductivity than the matrix metal 2 are used. Thereby, the carbon fiber composite metal material 1 according to the present embodiment has a high thermal conductivity that cannot be achieved by the matrix metal 2 alone. Examples of such carbon fibers include pitch-based carbon fibers. The pitch-based carbon fiber is a carbon fiber made from a double product such as petroleum, coal, coal tar and the like. Pitch-based carbon fibers are characterized in that high thermal conductivity can be obtained. For example, those having a thermal conductivity of about 500 W / m · K are obtained. This thermal conductivity is higher than that of copper (Cu, 400 W / m · K) having the highest thermal conductivity. Since the thermal conductivity of the matrix metal 2 varies depending on the type of metal, it is desirable to use pitch-based carbon fibers adjusted to a suitable thermal conductivity according to the thermal conductivity of the matrix metal 2.

  In the present embodiment, the first carbon fiber 3A and the second carbon fiber 3B can use those having a thermal conductivity in the range of 240 W / m · K to 2000 W / m · K, and a thermal conductivity of 400 W / m · K. The thing of the range of K or more and 1300 W / m * K or less is preferable, and the thing of the range whose heat conductivity is 500 W / m * K or more and 1000 W / m * K or less can be used more preferable. If it is such a range, the heat conductivity of the carbon fiber composite metal material 1 can be improved effectively.

  When a carbon fiber group (3A + 3B) having a plurality of types of diameters is obtained, the matrix metal 2 (FIG. 1-1) is formed on the surfaces of the first carbon fiber 3A and the second carbon fiber 3B constituting the carbon fiber group. Etc.) (step S102). As the parent phase metal 2, for example, Cu, Al, Ag, Mg, W, Mo, Zn, or an alloy thereof can be used. Of these materials, if a material having a high thermal conductivity is used as the matrix metal 2, the thermal conductivity of the entire carbon fiber composite metal material 1 can be increased.

  In the present embodiment, the surface of the first carbon fiber 3A and the second carbon fiber 3B is coated with the matrix metal 2 using a plating method to form a coating layer of the matrix metal 2. If the plating method is used, the plating solution adheres to every corner of the bundled carbon fibers, so that it is preferable to form the coating layer of the matrix metal 2 uniformly and reliably. Moreover, according to the plating method, the coating layer of the parent phase metal can be formed easily and inexpensively. The method of forming the coating layer of the parent phase metal 2 is not limited to the plating method, and for example, a PVD (Physical Vapor Deposition) method, a CVD (Chemical Vapor Deposition) method, or other thin film forming methods may be used. it can. The method of forming the coating layer of the parent phase metal 2 can be properly used according to the type of the parent phase metal 2. For example, other methods (for example, PVD method or CVD method) can be applied.

  FIG. 5 is a schematic diagram showing a cross section of the first carbon fiber 3A and the second carbon fiber 3B on which the coating layer of the matrix metal 2 is formed. As shown in FIG. 5, on the surfaces of the first carbon fiber 3A and the second carbon fiber 3B, the coating layers of the mother phase metal 2 (first mother phase metal layer 2MA and second mother phase metal layer 2MB) are respectively plated by plating. Is formed. Hereinafter, for convenience of explanation, the first carbon fiber 3A and the second carbon fiber 3B on which the coating layer of the matrix metal 2 is formed are referred to as a first coated carbon fiber 4A and a second coated carbon fiber 4B, respectively.

  FIG. 6 shows a state in which the first coated carbon fiber 4A and the second coated carbon fiber 4B are cut to a predetermined length. The first coated carbon fiber 4A and the second coated carbon fiber 4B on which the coating layer of the matrix metal 2 is formed are cut to a predetermined length (step S103). Here, the 1st carbon fiber 3A and the 2nd carbon fiber 3B have the characteristics that the thermal conductivity in the extending | stretching direction is extremely larger than the thermal conductivity in the direction orthogonal to the extending | stretching direction of a fiber.

  That is, the first carbon fiber 3A and the second carbon fiber 3B are directional in the direction of heat transfer, and by using this, heat can be conveyed in one direction toward the fiber extension direction. In the present embodiment, the carbon fiber composite metal member 1B using the carbon fiber composite metal material 1 according to the present embodiment has the first carbon fiber 3A and the second carbon fiber 3B aligned in the fiber extension direction and bundled in one direction. Since it is arranged in the matrix metal, heat can be conveyed in the extending direction of the first carbon fiber 3A and the second carbon fiber 3B. On the other hand, almost no heat moves in the direction other than the extending direction of the first carbon fiber 3A and the second carbon fiber 3B, and the heat escape to the direction other than the extending direction is reduced. Thereby, the carbon fiber composite metal member 1B using the carbon fiber composite metal material 1 according to the present embodiment efficiently transports heat in the extending direction of the first carbon fiber 3A and the second carbon fiber 3B. Can do.

  The carbon fiber composite metal member 1B using the carbon fiber composite metal material 1 according to the present embodiment includes a plurality of carbon fibers (first carbon fiber 3A, second carbon fiber 3B) that are aligned in one direction. Carbon fibers are disposed in the matrix metal. In this state, when composite processing described later is performed, the dimension in the heat transfer direction of the carbon fiber composite metal member 1B becomes substantially equal to the dimension in the extension direction of the first carbon fiber 3A and the second carbon fiber 3B. Therefore, the predetermined length by which the first coated carbon fiber 4A and the second coated carbon fiber 4B are cut in step S103 is the length l in the heat transfer direction of the carbon fiber composite metal member 1B.

  The carbon fibers (the first carbon fibers 3A and the second carbon fibers 3B) constituting the carbon fiber composite metal material 1 according to the present embodiment are continuous fibers. In the case of using the carbon fiber composite metal material 1 according to the present embodiment as a heat transfer means, the continuous fiber means that the carbon fiber is continuous at least for the distance for transporting heat. The same applies to the case where the carbon fibers are bent and arranged, and the carbon fiber composite metal material 1 has a bent shape. As a result, the carbon fiber composite metal material 1 can exhibit high heat transfer performance. For example, in the carbon fiber composite metal member 1B shown in FIG. 6, when heat is transported in the extending direction of the first carbon fiber 3A and the second carbon fiber 3B constituting the carbon fiber composite metal member 1B, at least the heat transfer direction of the carbon fiber composite metal member 1B. For the length 1 in, the first carbon fiber 3A and the second carbon fiber 3B are continuous.

  The carbon fibers (the first carbon fibers 3A and the second carbon fibers 3B) constituting the carbon fiber composite metal material 1 according to the present embodiment are continuous fibers, and at least have the same length for the distance for transporting heat. Preferably there is. This is because if the length of the carbon fiber is insufficient at the distance for transporting heat, the heat transfer performance is remarkably lowered at that portion, and the heat transfer performance of the carbon fiber composite metal material 1 is lowered.

  A predetermined amount of the first coated carbon fiber 4A and the second coated carbon fiber 4B after cutting are aligned and set in a sintering mold (graphite mold) 12 (step S104). FIG. 7 shows a state in which a predetermined amount of the first coated carbon fiber 4A and the second coated carbon fiber 4B cut to a predetermined length are set in the cavity 12C of the mold 12. In this case, the first coated carbon fiber 4A and the second coated carbon fiber 4B are aligned so that the length direction (fiber elongation direction) is the same direction, and are arranged in one direction, so that the inside of the cavity 12C of the mold 12 Set to

  FIG. 8 shows the state of the first coated carbon fiber 4A and the second coated carbon fiber 4B before being combined. In the cavity 12C of the mold 12, the first matrix metal layer 2MA covering the surface of the first carbon fiber 3A is in contact with the first matrix metal layer 2MA covering the surface of the adjacent first carbon fiber 3A. Further, since the second carbon fiber 3B is disposed so as to be surrounded by the four first carbon fibers 3A, the second matrix metal layer 2MB covering the surface of the second carbon fiber 3B is the first carbon fiber. It contacts the first matrix metal layer 2MA covering the surface of 3A. In this state, the process proceeds to the next compounding step. Here, the distance between the first carbon fibers 3A after the complexing depends on the thickness t of the first matrix metal layer 2MA covering the surface of the first carbon fibers 3A. Therefore, by controlling the thickness t of the first matrix metal layer 2MA, the distance between the first carbon fibers 3A after the composite can be controlled.

  When a predetermined amount of the first coated carbon fiber 4A and the second coated carbon fiber 4B are set in the mold 12, the set predetermined amount of the first coated carbon fiber 4A and the second coated carbon fiber 4B are combined (step S105). . In this embodiment, sintering is used as a composite technique. As a result, the first carbon fiber 3A, the second carbon fiber 3B, and the matrix metal 2 are integrated and combined. In the present embodiment, SPS (Spark Plasma Sintering) is used as a sintering method. SPS applies ON-OFF DC pulse voltage and current to the objects to be sintered (first coated carbon fiber 4A and second coated carbon fiber 4B), and produces a sintered body by a discharge phenomenon that occurs in the gap between the sintered objects. It is a method to do. According to this, there is an advantage that a dense (high density) sintered body can be produced in a short time from a metal to a ceramic and further to a hardly sintered material. Note that the composite technique applicable to this embodiment is not limited to sintering. For example, HIP (Hot Isostatic Pressing), thermal plasma sintering, electric heating sintering, and others Can be used.

  When compounding (SPS in this embodiment) is completed, for example, a carbon fiber composite metal member 1B shown in FIG. 1-1 is completed. The completed carbon fiber composite metal member 1B may be used as it is, or the carbon fiber composite metal member 1B may be subjected to processing such as cutting or cutting according to the location or purpose of use (step S106). . By the above procedure, the carbon fiber composite metal material 1 (or the carbon fiber composite metal member 1B using the same) according to the present embodiment can be manufactured. Next, examples of the present invention will be described.

(Example)
By the above method, a carbon fiber composite metal material according to an example of the present invention in which two types of carbon fibers having different diameters were arranged in a matrix metal was manufactured. In addition, as a comparative example, a carbon fiber composite metal material in which carbon fibers having one type of diameter were arranged in a matrix metal was manufactured. FIG. 9-1 is a schematic diagram showing an arrangement of carbon fibers in a cross section of the carbon fiber composite metal material according to the present invention. FIG. 9-2 is a schematic diagram illustrating an arrangement of carbon fibers in a cross section of the carbon fiber composite metal material according to the comparative example.

In the carbon fiber composite metal material 1 according to the present invention, the first carbon fiber 3A has a diameter of 10 μm, the second carbon fiber 3B has a diameter of 7 μm, and both the first carbon fiber 3A and the second carbon fiber 3B are pitch-based carbon. Fiber was used. Pitch-based carbon fiber (trade name “XN90”) manufactured by Nippon Graphite Fiber was used as the first carbon fiber 3A. The pitch-based carbon fiber has a tensile modulus of 860 GPa, a tensile strength of 3430 MPa, a thermal conductivity of 500 W / m · K, and a density of 2.19 g / cm ³ . In addition, pitch carbon fiber (trade name “YS95”) manufactured by Nippon Graphite Fiber was used as the second carbon fiber 3B. This pitch-based carbon fiber has a tensile modulus of 920 GPa, a tensile strength of 3530 MPa, a thermal conductivity of 600 W / m · K, and a density of 2.19 g / cm ³ .

  As the parent phase metal 2, copper (Cu) was used. A carbon fiber group (3A + 3B) in which the first carbon fiber 3A and the second carbon fiber 3B were mixed was manufactured, and after copper plating was applied thereto, it was cut into a predetermined length (about 25 mm). And the cut | disconnected carbon fiber group (3A + 3B) was set up in a graphite mold, and SPS was performed in vacuum, and the carbon fiber composite metal material 1 which concerns on this invention was obtained (refer FIG. 9-1).

In the carbon fiber composite metal material 101 according to the comparative example, pitch-based carbon fibers having a diameter of 10 μm were used as the carbon fibers 103. As the carbon fiber 103, pitch-based carbon fiber (trade name “YS95A”) made of Nippon Graphite Fiber was used. The pitch-based carbon fiber has a tensile modulus of 900 GPa, a tensile strength of 3530 MPa, a thermal conductivity of 600 W / m · K, and a density of 2.19 g / cm ³ . Further, copper (Cu) was used as the parent phase metal 102. The carbon fiber 103 was subjected to copper plating and then cut to a predetermined length (about 25 mm). Then, the cut carbon fibers 103 were aligned and set in a graphite mold, and SPS was performed under vacuum to obtain a carbon fiber composite metal material 101 according to a comparative example (see FIG. 9-2). Table 1 shows examples of the present invention and comparative examples.

The densities of the carbon fiber composite metal material 1 according to the present invention and the carbon fiber composite metal material 101 according to the comparative example were measured at room temperature (25 ° C.) by an Archimedes method using an electronic analytical balance. The specific heat of the carbon fiber composite metal material 1 according to the present invention and the carbon fiber composite metal material 101 according to the comparative example is measured using a differential scanning calorimeter (trade name “EXSTAR6000”) manufactured by Seiko Instruments Inc., and DSC (Differential Scanning Calorimetry: (Differential scanning calorimetry) method, the heating rate is 5 ° C./min. Measured from room temperature in a dry nitrogen stream. Sapphire (a mineral mainly composed of Al ₂ O ₃ ) was used for comparative calibration.

  The thermal conductivity of the carbon fiber composite metal material 1 according to the present invention and the carbon fiber composite metal material 101 according to the comparative example was calculated from the thermal diffusivity. The thermal diffusivity of the carbon fiber composite metal material 1 according to the present invention and the carbon fiber composite metal material 101 according to the comparative example was measured using a laser flash device (trade name “TC-7000”) manufactured by ULVAC-RIKO. Then, the thermal conductivity of the carbon fiber composite metal material 1 according to the present invention and the carbon fiber composite metal material 101 according to the comparative example was calculated by multiplying the measured thermal diffusivity by the density and specific heat.

  The volume ratio of the first carbon fiber 3A and the second carbon fiber 3B is a ratio of the volume of the first carbon fiber 3A to the volume of the second carbon fiber 3B with respect to all the carbon fibers. The volume ratio of carbon fibers is the ratio of the volume of all carbon fibers to the total volume of the carbon fiber composite metal material according to the example or the comparative example. The presence or absence of voids and cracks was observed by magnifying the inside of the cross section perpendicular to the carbon fiber, and when the presence of voids and cracks could be confirmed, it was determined that there were voids and cracks. The thickness of the copper plating is the thickness of the matrix metal coating layer formed on the surface of the carbon fiber. Here, the minimum gap S between adjacent first carbon fibers 3A (see FIG. 9-1) or the minimum gap S between adjacent carbon fibers 103 (see FIG. 9-2) is 2 of the thickness of the copper plating. The size of the minimum interval S varies depending on the manufacturing conditions of the carbon fiber composite metal material.

As can be seen from the results in Table 1, in Examples 1 to 3 of the present invention, neither voids nor cracks are observed, and it is judged that a practically sufficient strength can be obtained. Moreover, in Examples 1-3 of this invention, the volume ratio of carbon fiber has secured 60% or more. The thermal conductivity of Examples 1 to 3 of the present invention is higher than the thermal conductivity (Cu, 400 W / m · K) of copper used as the parent phase metal, and is required as a whole carbon fiber composite metal material. It can be said that heat conductivity can be secured. Moreover, the density of Examples 1-3 of this invention is lower than the density (8.92 g / cm < ³ >) of copper which is a parent phase metal. Thus, Examples 1 to 3 of the present invention can achieve higher thermal conductivity than the parent phase metal, and can achieve lighter weight than the parent phase metal. Here, from the viewpoint of ensuring thermal conductivity, the volume ratio of the carbon fibers is preferably 50% or more, and preferably 80% or less from the viewpoint of ensuring strength.

  Moreover, as for the heat conductivity of Examples 1-3 of this invention, all are higher than the heat conductivity of Comparative Examples 1-4, Examples 1-3 of this invention are Comparative Examples 1-4. In contrast, it can be seen that high thermal conductivity can be obtained. Here, Example 1 of the present invention has a higher density than Comparative Example 1, and Example 3 of the present invention has a higher density than Comparative Example 2. However, as described later, in Comparative Examples 1 and 2, voids and cracks are observed, and it is determined that these are insufficient in practical strength. Therefore, in Comparative Examples 1 and 2, it is considered that securing of strength, improvement in thermal conductivity, and weight reduction cannot be achieved at the same time. On the other hand, in Examples 1 to 3, no voids or cracks are observed, and it is determined that practically sufficient strength can be obtained, and improvement in thermal conductivity and weight reduction can be achieved at the same time.

  The specific heat conductivity of Examples 1 to 3 of the present invention, that is, the value obtained by dividing the thermal conductivity by density is higher than the specific heat conductivity of Comparative Examples 1 to 4, and Example 1 of the present invention. It can be seen that ˜3 is higher specific heat conductivity than Comparative Examples 1-4. That is, if it is the same density, it can be judged that Examples 1-3 of this invention are more advantageous than Comparative Examples 1-4 with respect to weight reduction, improving a heat conductivity.

  In Examples 1 to 3, the first carbon fiber 3 </ b> A and the second carbon fiber 3 </ b> B having a smaller diameter are disposed in the matrix metal 2. As a result, as shown in FIG. 9A, since the second carbon fiber 3B enters the region surrounded by the first carbon fiber 3A, the volume ratio of the carbon fibers can be increased. Accordingly, the bonding area between the first and second carbon fibers 3A and 3B and the matrix metal 2 can be secured while increasing the volume ratio of the carbon fibers, so that the strength of the carbon fiber composite metal material 1 can be secured. It is done.

  On the other hand, when the carbon fiber 103 having a single diameter is used (comparative example), voids and cracks are observed in comparative examples 1 and 2, and it is determined that these are insufficient in practical strength. Moreover, in the volume ratio of the carbon fiber 103 in Comparative Examples 1 and 2, it is determined that the bonding area with the parent phase metal 102 is reduced and the strength reduction is further increased. In Comparative Examples 3 and 4, voids and cracks are not observed, but the volume ratio of the carbon fibers is less than 50%, and it is judged that it is difficult to ensure the thermal conductivity of the entire carbon fiber composite metal material. As described above, in the comparative example, when the volume ratio of the carbon fiber is increased to increase the thermal conductivity of the carbon fiber composite metal material 101, the strength of the carbon fiber composite metal material 101 is decreased. That is, in the comparative example, it is considered extremely difficult to simultaneously achieve high thermal conductivity, ensuring strength, and reducing weight.

  From the results of Table 1, in the present invention, the volume ratio of the first carbon fiber 3A and the other carbon fibers, that is, the second carbon fiber 3B, is preferably 85:15 or more and 95: 5 or less. The diameter of the second carbon fiber 3B having a smaller diameter than the first carbon fiber 3A is preferably 60% or more and 75% or less of the diameter of the first carbon fiber. Further, the minimum gap S between the first carbon fibers 3A is preferably 20% or more and 30% or less of the diameter of the first carbon fibers 3A. When the parameter is within this range, it is determined that the carbon fiber composite metal material according to the present invention can simultaneously achieve thermal conductivity, strength, and weight reduction.

  As described above, in the carbon fiber composite metal material of the present embodiment, a plurality of carbon fibers having higher thermal conductivity in the fiber extension direction than the metal constituting the mother phase are aligned in the metal mother phase with the fiber extension direction aligned. The arrangement is made and the diameter of the carbon fiber is configured to have at least two kinds of sizes. This makes it possible to increase the volume ratio of carbon fibers contained in the metal matrix (volume ratio to the carbon fiber composite metal material), thereby ensuring the strength of the carbon fiber composite metal material and improving the thermal conductivity. And weight reduction can be achieved simultaneously.

  In addition, since carbon fibers having a relatively small diameter are arranged in a space surrounded by carbon fibers having a relatively large diameter, when a carbon fiber coated with a metal is combined by sintering, a metal coating is used. Even if the layer is made small, the bonding area between the carbon fiber and the metal matrix can be secured. As described above, the carbon fiber composite metal material according to the present embodiment is particularly advantageous when the carbon fiber coated with metal is combined by sintering.

  The carbon fiber composite metal material of the present embodiment can be used as, for example, a heat transfer element that conveys heat from a high temperature portion to a low temperature portion. Applications of such heat transfer elements include, for example, heat dissipation and temperature control of electrical and electronic equipment, heat dissipation and temperature control of equipment mounted on artificial satellites, and heat engines such as internal combustion engines and external combustion engines. For example, heat dissipation.

  As described above, the carbon fiber composite metal material according to the present invention is useful for obtaining high thermal conductivity with a composite material of carbon fiber and metal, and in particular, improves the thermal conductivity while ensuring strength. At the same time, it is suitable for achieving weight reduction.

It is a perspective view which shows the member comprised with the carbon fiber composite metal material of this embodiment. It is a side view which shows the member comprised with the carbon fiber composite metal material of this embodiment. It is a schematic diagram which shows the structure of the carbon fiber composite metal material which concerns on this embodiment. It is a schematic diagram which shows the structure of the carbon fiber composite metal material which concerns on this embodiment. It is a schematic diagram which shows the structure of the carbon fiber composite metal material which concerns on this embodiment. It is a flowchart which shows an example of the manufacture procedure of the carbon fiber composite metal material which concerns on this embodiment. It is a schematic diagram for demonstrating the manufacturing procedure of the carbon fiber composite metal material which concerns on this embodiment. It is a schematic diagram for demonstrating the manufacturing procedure of the carbon fiber composite metal material which concerns on this embodiment. It is a schematic diagram for demonstrating the manufacturing procedure of the carbon fiber composite metal material which concerns on this embodiment. It is a schematic diagram for demonstrating the manufacturing procedure of the carbon fiber composite metal material which concerns on this embodiment. It is a schematic diagram for demonstrating the manufacturing procedure of the carbon fiber composite metal material which concerns on this embodiment. It is a schematic diagram which shows the arrangement | sequence of the carbon fiber in the cross section of the carbon fiber composite metal material which concerns on this invention. It is a schematic diagram which shows the arrangement | sequence of the carbon fiber in the cross section of the carbon fiber composite metal material which concerns on a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carbon fiber composite metal material 1B Carbon fiber composite metal member 2 Matrix metal 2MA 1st matrix metal layer 2MB 2nd matrix metal layer 3A 1st carbon fiber 3B 2nd carbon fiber 3C 3rd carbon fiber 4A 1st coating carbon Fiber 4B Second coated carbon fiber 10 Spinning nozzle 11A First nozzle hole 11B Second nozzle hole 12 Mold 12C Cavity 101 Carbon fiber composite metal material 102 Base metal 103 Carbon fiber

Claims (10)

  A plurality of pitch-based carbon fibers having a higher thermal conductivity in the fiber elongation direction than the metal are arranged in the metal matrix, and the fibers are arranged in the matrix. The carbon fiber composite metal material, wherein the carbon fiber has a diameter of at least two kinds. The carbon fiber is
A first carbon fiber having the largest diameter among the carbon fibers contained in the matrix and a plurality of carbon fibers arranged in the matrix with the fiber extending direction aligned;
A plurality of first carbon fibers and a second carbon fiber that is arranged in the matrix with the fibers extending in the same direction and has a diameter smaller than that of the first carbon fibers;
The carbon fiber composite metal material according to claim 1, comprising:   The carbon fiber composite metal material according to claim 2, wherein the second carbon fiber is disposed between the first carbon fibers.   4. The carbon fiber composite metal material according to claim 2, wherein a volume ratio of the first carbon fiber to the other carbon fiber is 85:15 or more and 95: 5 or less.   5. The diameter of the carbon fiber having a smaller diameter than the first carbon fiber is 60% or more and 75% or less of the diameter of the first carbon fiber. The carbon fiber composite metal material described.   The carbon fiber composite according to any one of claims 2 to 5, wherein a minimum gap between the first carbon fibers is 20% or more and 30% or less of a diameter of the first carbon fiber. Metal material.   The carbon fiber composite metal material according to any one of claims 2 to 6, wherein the carbon fibers are continuous fibers, and the lengths in the extension direction of the fibers are aligned.   The carbon metal composite metal material according to any one of claims 1 to 7, wherein the metal is Cu, Al, Ag, Mg, W, Mo, Zn, or an alloy thereof.   The carbon fiber composite metal material according to any one of claims 1 to 8, wherein a volume ratio of the carbon fiber to the carbon fiber composite metal material is 50% or more and 80% or less.   10. The carbon fibers coated with the matrix metal are combined by bundling a plurality of fibers in the same direction of fiber elongation and pressurizing and sintering the carbon fibers. The carbon fiber composite metal material described in 1.

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