JP2857870B2 - Fiber content adjusted three-dimensional woven fabric, heat-resistant fiber reinforced composite material for metal joining using the woven fabric, and joining method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the joining of a heat-resistant composite material reinforced with fiber by a three-dimensional fabric and a metal.
More specifically, the present invention relates to a three-dimensional woven fabric used for a three-dimensional fiber-reinforced heat-resistant composite material having good bondability with a metal, a heat-resistant composite material having the structure of the woven fabric, and a method of bonding the composite material to a metal.

[0002]

2. Description of the Related Art A heat-resistant composite material is a carbon fiber reinforced composite material (hereinafter abbreviated as "C / C material") or a ceramic composite material (hereinafter abbreviated as "FRC" as appropriate). / C material and FRC are very excellent materials in terms of high-temperature strength and heat resistance, and have begun to be applied to high-temperature members in the aerospace field, the nuclear reactor field, and the like. I have. As a fiber reinforcing method of the heat-resistant composite material, a method using a nonwoven fabric, one-way reinforcing, two-dimensional woven fabric lamination, three-dimensional woven fabric, or the like is known. In this case, a reinforcing method is selected depending on the application, but since the reinforcing method using a three-dimensional fabric becomes more isotropic, application to a high-performance member is expected.

When a heat-resistant composite material such as the above-mentioned C / C material or FRC is bonded to a metal, the one-way reinforced C / C material has a coefficient of thermal expansion of 10 × in a plane perpendicular to the fiber reinforced direction.
Is about 10 ^-6 / K, the thermal expansion of the metal to be joined (e.g., Ni-base superalloys: about 14 × 10 ^-6 / K, copper alloys to about 15 × 10 ^-6 / K) as compared to Since the difference in thermal expansion is small, good joining can be performed. In addition, unidirectional reinforcement C / C
As for the materials, good bondability has been reported in nuclear power. As shown in FIG. 3, a C / C material 10 reinforced with a three-dimensional woven fabric is made of a metal 14 using a brazing material 12.
When the three-dimensional fabric reinforced C / C material is bonded, the coefficient of thermal expansion is about 1 × 10 ⁻⁶ / K due to fiber reinforcement, and the coefficient of thermal expansion of the metal to be bonded (in the case of FIG.
telloy) X: 16.6 × 10 ⁻⁶ / K (1250)
K), 13.9 × 10 ^-6 / K (370K))
There is a thermal expansion difference of 10 times or more.

Conventionally, as shown in Japanese Patent Application Laid-Open No. 3-182337, several intermediate layers are provided between a carbon fiber reinforced ceramic and a metal substrate, and a gradient composition is formed from the metal substrate to the carbon fiber reinforced ceramic. It is known that the stress relaxation caused by the difference in the thermal expansion coefficient is reduced and the thermal stability of the stress relaxation structure is suppressed by suppressing the reaction. Further, as disclosed in Japanese Patent Publication No. 6-31165, a unidirectional fiber reinforced soft metal is disposed at a joint between a metal and a ceramic so that the fiber orientation direction is perpendicular to the joint surface, and the metal and the ceramic are joined together. It is known that thermal stress due to the difference in thermal expansion coefficient from ceramics is reduced.

[0005]

As described above, a heat-resistant composite material having a structure such as a three-dimensional fabric has a very low coefficient of thermal expansion as compared with a metal. Due to the difference in expansion, peeling at the bonding surface (interface) or the like was caused, and the bonding property was poor. Further, as shown in FIG. 3, the thermal expansion coefficient of the three-dimensional woven fabric reinforced C / C material is compared with the thermal expansion coefficient of the metal to be joined (Hastelloy X). Since the ratio is 10 times or more smaller, cracks or peeling at the joint surface due to the difference in thermal expansion may occur. Further, there is also a problem that the permeability of the brazing material is deteriorated due to the low porosity of the C / C material, and good bonding properties cannot be obtained.

[0006] The composite material joined body described in Japanese Patent Application Laid-Open No. 3-182337 has a problem in that an ion plating apparatus or the like is used at the time of manufacture, or an intermediate layer is arranged so as to have a gradient composition. The production and operation are extremely complicated, and a simpler method is desired. Tokuhei 6-311
The bonded article described in Japanese Patent Application Laid-Open No. 65-265 is provided with a stress relaxation layer having a thermal expansion coefficient made of a unidirectional fiber reinforced metal whose base material is a soft metal, but the bonding method is extremely complicated.

The present invention has been made in view of the above points, and an object of the present invention is to adjust the coefficient of thermal expansion and the porosity in the surface direction near the metal bonding surface in a three-dimensional fiber-reinforced heat-resistant composite material. It is an object of the present invention to provide a three-dimensional woven fabric used for a three-dimensional fiber-reinforced heat-resistant composite material having good bondability with a metal, a heat-resistant composite material having the structure of the woven fabric, and a method of joining the composite material with a metal.

[0008]

In order to achieve the above-mentioned object, a three-dimensional fiber-content-adjusted woven fabric of the present invention comprises a three-dimensional fiber-reinforced heat-resistant composite material which is bonded to a metal and a bonding surface in the vicinity thereof. Of the three-dimensional fiber reinforced heat-resistant composite material, and the coefficient of thermal expansion in the direction of the joint surface is increased and adjusted. In the three-dimensional woven fabric of the present invention, at least one of expanding the interval in the thickness direction of the fiber with respect to the bonding surface in the bonding surface direction and reducing the number of fibers per fiber bundle in the fiber in the bonding surface direction. By doing
The fiber content in the joining surface direction can be reduced. Also,
In the above-described three-dimensional fabric of the present invention, by increasing the number of fibers per fiber bundle in the fibers in the thickness direction with respect to the bonding surface, and increasing the number of fiber bundles, by performing at least one of the bonding surface The fiber content in the direction can also be reduced. Then, a heat-resistant fiber-reinforced composite material for metal bonding with good bondability to metal can be manufactured using the three-dimensional fiber content-adjusted woven fabric configured as described above.

Further, the heat-resistant fiber-reinforced composite material for metal bonding of the present invention has a slit provided in a direction perpendicular to the bonding surface on a surface to be bonded to a metal as a three-dimensional fiber-reinforced heat-resistant composite material, and the fiber in the bonding surface direction is provided. Are cut to increase and adjust the coefficient of thermal expansion of the three-dimensional fiber-reinforced heat-resistant composite material in the direction of the joint surface, and increase the voids in the joint surface and the vicinity thereof. In addition, a slit is provided in a direction perpendicular to the bonding surface on a surface to be bonded to the metal of the heat-resistant composite material having the above-mentioned fiber content adjustment three-dimensional woven fabric structure, and the fiber in the bonding surface direction is cut to form a metal joint. The thermal expansion coefficient of the heat-resistant fiber reinforced composite material in the joining surface direction can be increased and adjusted, and the gap at the joining surface and the vicinity thereof can be increased.

Further, the method for bonding a heat-resistant fiber-reinforced composite material for metal bonding according to the present invention reduces the fiber content of the surface to be bonded to the metal as a three-dimensional fiber-reinforced heat-resistant composite material and the bonding surface direction in the vicinity thereof, thereby reducing Increase the coefficient of thermal expansion in the joining surface direction of the original fiber reinforced heat-resistant composite material, produce a fiber content adjusted three-dimensional fabric adjusted to match the coefficient of thermal expansion of the metal to be joined, and manufacture the metal manufactured using the fabric. It is characterized in that the heat-resistant fiber-reinforced composite material for joining is brazed to a metal. In addition, the method for bonding a heat-resistant fiber-reinforced composite material for metal bonding according to the present invention includes the steps of: providing a slit in a direction perpendicular to the bonding surface on a surface to be bonded to a metal as a three-dimensional fiber-reinforced heat-resistant composite material; By cutting the three-dimensional fiber reinforced heat-resistant composite material, the coefficient of thermal expansion in the direction of the joint surface was increased, and adjusted to match the coefficient of thermal expansion of the metal to be joined, and the voids in the joint surface and its vicinity were increased. The method is characterized in that a three-dimensional fabric for adjusting the fiber content is manufactured, and a heat-resistant fiber-reinforced composite material for metal bonding manufactured using the fabric is brazed to a metal.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described using a heat resistant composite material having a structure of a three-dimensional reinforced three-dimensional fabric as shown in the drawings. It is not limited to three-dimensional fabrics,
The present invention can be applied to all three-dimensional fabrics such as other three-dimensional reinforced three-dimensional fabrics and four-directional reinforced three-dimensional fabrics. For example, the structure of the three-dimensional fabric of the present invention can be applied to a case of a cylindrical coordinate system. FIG. 1 shows a case where a method for joining a heat-resistant fiber-reinforced composite material for metal joining according to a first embodiment of the present invention is performed. This embodiment reduces the fiber content in the bonding surface direction in the surface to be bonded to the metal as the three-dimensional fiber-reinforced heat-resistant composite material and in the vicinity thereof, and reduces the thermal expansion coefficient in the bonding surface direction of the three-dimensional fiber-reinforced heat-resistant composite material. It is a case to increase. In FIG. 1, reference numeral 16 denotes a carbon fiber reinforced composite material (C / C material) in which reinforcing fibers in a longitudinal direction (X direction) and a lateral direction (Y direction) are provided orthogonal to a metal bonding surface direction. , Y-directional yarn 18 has a structure of an orthogonal three-directional reinforced three-dimensional woven fabric in which the reinforcing fibers (Z-directional yarn 20) in the thickness direction (Z direction) with respect to the joining surface are orthogonal to each other. 22 is a metal to be joined to the C / C material,
4 is a brazing material used for joining.

As shown in FIG. 1, in the three-dimensional fiber reinforced heat-resistant composite material, the X / Y direction yarns in the plane direction (X direction or Y direction) in the surface where the C / C material 16 is bonded to the metal 22 and in the vicinity thereof. Either by removing several layers of the fibers 18 or the like to increase the spacing between the reinforcing fibers in the thickness direction, or by reducing the number of fibers in the fiber bundle of the X, Y-direction yarns 18, or
By increasing the number of fibers in the fiber bundle of the Z-direction yarn 20 in the thickness direction or by increasing the number of fiber bundles, the fiber content in the joint surface direction is reduced, and the coefficient of thermal expansion in the joint surface direction is increased. , The coefficient of thermal expansion of the metal 22 to be joined (for example, Ni-based super heat-resistant alloy: about 14 × 10 ⁻⁶ / K, copper alloy: about 15 × 10 ⁻⁶ /
A three-dimensional carbon fiber fabric adjusted to meet K) is manufactured, and the C / C material 16 is manufactured using the three-dimensional fabric. In addition, a three-dimensional fabric is manufactured using ceramic fibers as the reinforcing fibers, and a ceramic-based composite material (FR
The same applies to the case of producing C). It is of course possible to use other fibers other than carbon fibers and ceramic fibers as the reinforcing fibers.

When carbon fibers are used, pitch-based, polyacrylonitrile-based or rayon-based fibers can be used, but pitch-based carbon fibers are preferred. The pitch-based carbon fiber referred to here is a fiber obtained by melt-spinning a carbonaceous pitch, making it infusible, carbonized and, if necessary, graphitized. In addition, the ceramic fiber is Si
Fibers made of carbide ceramics such as C and TiC, oxide ceramics such as Al ₂ O ₃ , nitride ceramics such as Si ₃ N ₄ or a mixture thereof. In addition, carbon fibers coated on the surface with the above ceramics are also included. These carbon fibers and ceramic fibers usually have a diameter of 5 to several tens of μm, and
The woven fabric is woven into a bundle of 0000 pieces.

The C / C material 16 manufactured as described above
Is a three-dimensional fiber-reinforced heat-resistant composite material. One surface not bonded to the metal 22 has a relatively isotropic property and a low coefficient of thermal expansion (about 1 × 10 ⁻⁶ / K), while the other surface has a surface direction. Has a high coefficient of thermal expansion (approximately 10 × 10 ⁻⁶ / K), and can be joined using a metal 22 and a brazing material 24 having similar thermal expansion coefficients.
When metal is to be bonded to both surfaces, the fiber content of both bonding surfaces and the vicinity thereof is reduced by the above-described means, so that both surfaces have characteristics close to unidirectional reinforcing material (high coefficient of thermal expansion). In addition, a material having the properties of a three-dimensional fiber-reinforced heat-resistant composite material (high strength and low coefficient of thermal expansion) at the center can also be used. The brazing material 24 used for bonding includes a material whose main component is silver, platinum, copper, nickel, palladium, or the like, and to which tin, titanium, indium, gallium, germanium, or the like is added as an additional element. The form of the brazing material may be powder, foil, or a wire. The melting point of the brazing material is determined in a vacuum atmosphere (preferably about 10 ^-5 Torr), an inert atmosphere (nitrogen, helium, argon gas atmosphere) or the atmosphere. Above temperature (for example, 700 to 1100 ° C)
Is heated and joined. In order to prevent metal oxidation and the like, it is preferable to perform brazing in a vacuum atmosphere.

FIG. 2 shows a case where a method for joining a heat-resistant fiber-reinforced composite material for metal joining according to a second embodiment of the present invention is carried out. In the present embodiment, a three-dimensional fiber-reinforced heat-resistant composite material is provided by providing a slit in a direction perpendicular to the bonding surface on a surface to be bonded to a metal as a three-dimensional fiber-reinforced heat-resistant composite material, and cutting fibers in a bonding surface direction. This is the case where the coefficient of thermal expansion and the porosity in the direction of the joining surface of the material are increased. In addition, not only the case where the slit is provided in the ordinary three-dimensional fiber reinforced heat-resistant composite material, but also the slit is provided in the three-dimensional fiber reinforced heat-resistant composite material in which the fiber content in the bonding surface direction in the metal bonding surface and the vicinity thereof is reduced. In some cases. In FIG. 2, reference numeral 16 denotes a carbon fiber reinforced composite material (C / C material), which has a longitudinal direction (X direction) and a lateral direction (Y
Directions), and the X, Y direction yarns 18 are orthogonal to the reinforcing fibers (Z direction yarns 20) in the thickness direction (Z direction) with respect to the joining surface. It has the structure of a reinforced three-dimensional fabric. Reference numeral 22 denotes a metal to be joined to the C / C material, reference numeral 24 denotes a brazing material used for joining, and reference numeral 26 denotes a slit provided perpendicular to the metal joining surface.

As shown in FIG. 2, in the three-dimensional fiber-reinforced heat-resistant composite material in which the fiber content is adjusted or in the ordinary three-dimensional fiber-reinforced heat-resistant composite material, the C / C material 16 By providing a slit 26 perpendicular to the joining surface and cutting several layers of the fibers (X, Y-direction yarns 18) in the thickness direction in the thickness direction, the coefficient of thermal expansion in the joining surface direction is increased, and the metal to be joined is cut. While adjusting so as to match the coefficient of thermal expansion of 22, the joint surface and the voids in the vicinity thereof are increased,
The C / C material 16 is joined to the metal 22 using the brazing material 24. The width of the slit depends on the fabric structure,
It is 1 μm to 5 mm, preferably 10 μm to 2 mm.
Further, the depth of the slit is such that the fibers in the surface direction are cut one or more times from the viewpoint of increasing the coefficient of thermal expansion in the bonding surface direction. As an example, the slits are placed in one direction or in a grid pattern (lattice shape). When the slits are placed, it is preferable to cut the surface direction fibers as finely as possible from the viewpoint of increasing the coefficient of thermal expansion in the bonding surface direction. It should be noted that cutting every 1 to 10 bundles is sufficiently effective. Further, by providing the slit, not only the adjustment of the coefficient of thermal expansion described above, but also increases the voids near the joining surface, the brazing material well penetrates the joining surface of the heat-resistant composite material, and with the metal by the anchor effect. Is improved. The C / C material 16 manufactured as described above is a three-dimensional fiber-reinforced heat-resistant composite material, and one surface not bonded to the metal 22 has a relatively isotropic property and a low coefficient of thermal expansion (about 1 × 10 ^-6 / K) porosity is small (preferably 10% or less), while the other side has a high thermal expansion coefficient in the plane direction (about 10 × 10 ^-6 / K) and a large porosity (preferably 15%). % Or more), the metal 22 and the brazing material 24 having similar thermal expansion coefficients can be joined.

[0017]

Next, examples of the present invention and comparative examples will be described. Example 1 A surface direction yarn (X, Y direction) on the joining surface side of a 5 mm-thick orthogonal three-direction reinforced three-dimensional woven fabric having six layers of fiber bundles of X, Y direction yarns in the thickness direction (Z direction) with metal 3) from the bonding surface side to increase the surface spacing in the thickness direction of the carbon fiber.
Pitch impregnation, 1000 ° C, 100MPa pressure carbonization and 17
The densification treatment of sintering at 00 ° C. is repeated six times to produce a high-density carbon fiber reinforced heat-resistant composite material, and a Ni-based super heat-resistant alloy (N
i 47.3wt%, Cr 22.0wt%, Co 1.5wt
%, Mo 9.0 wt%, W 0.6 wt%, Fe 18.5 w
t%, Mn 0.5wt%, Si 0.5wt%, C 0.1wt
%) And a bonding test by brazing. As the brazing material, silver (Ag 63 wt%, Cu 35 wt%, Ti 2w
%) and a foil having a thickness of 100 μm and a thickness of 10 ⁻⁵ Torr
Was heated to 850 ° C. for 5 minutes under a high vacuum to join the C / C material and the metal. As a result of examining the state of the cross section, it was confirmed that there was no separation at the interface (joining surface), and that the joining was good.

Example 2 A 3 mm-thick orthogonal three-way reinforced three-dimensional fabric having four layers of fiber bundles in the X and Y directions in the thickness direction (Z direction) was impregnated with pitch and carbonized under pressure at 1000 ° C. and 100 MPa. And a densification treatment of firing at 1700 ° C. was repeated six times to produce a high-density C / C material. Thereafter, slits having a depth of 1.5 mm and a width of 0.3 mm were formed at intervals of 2 mm on the metal bonding surface of the C / C material in a lattice shape. By providing slits, the porosity near the joint surface increased from about 6% to about 30%. And this C /
C material and Ni-base super heat resistant alloy (Ni 47.3wt%, Cr 2
2.0 wt%, Co 1.5 wt%, Mo 9.0 wt%, W
0.6 wt%, Fe 18.5 wt%, Mn 0.5 wt%, S
i 0.5 wt%, C 0.1 wt%). The joining method uses silver (Ag 63 wt.
%, Cu 35 wt%, and Ti 2 wt%) in a foil shape having a thickness of 100 μm under a high vacuum of 10 ⁻⁵ Torr for 8 minutes.
It was heated to 50 ° C. to join the C / C material and the metal. As a result of examining the state of this cross section, the interface (joining surface)
, And it was confirmed that the bonding was good.

Comparative Example 1 Pitch impregnation, 1000 ° C., 100 MPa pressure carbonization using a 3 mm-thick orthogonal three-way reinforced three-dimensional woven fabric having four layers of fiber bundles of X and Y directions in the thickness direction (Z direction). And a densification treatment of firing at 1700 ° C. was repeated six times to produce a high-density C / C material. Then, the C / C material and the Ni-based super heat-resistant alloy (N
i 47.3wt%, Cr 22.0wt%, Co 1.5wt
%, Mo 9.0 wt%, W 0.6 wt%, Fe 18.5 w
t%, Mn0.5wt%, Si 0.5wt%, C 0.1wt
%). The joining method is as follows: silver (Ag 63 wt%, Cu 35 wt%, Ti 2 wt
Used as foil having a thickness of 100μm in%), 10 ^-5 Torr
Was heated to 850 ° C. for 5 minutes under high vacuum to join the C / C material and the metal. As a result of examining the state of the cross section, peeling was observed at the interface (bonding surface) between the C / C material and the metal.

[0020]

As described above, the present invention has the following effects. (1) By lowering the fiber content in the direction of the bonding surface in the surface to be bonded to the metal as the three-dimensional fiber-reinforced heat-resistant composite material and in the vicinity thereof, increasing the coefficient of thermal expansion in the direction of the bonding surface of the three-dimensional fiber-reinforced heat-resistant composite material; By adjusting to the thermal expansion coefficient of the metal to be joined, the difference in thermal expansion between the three-dimensional fiber-reinforced heat-resistant composite material and the metal to be joined becomes smaller,
The three-dimensional fiber-reinforced heat-resistant composite material can be brazed to a metal without causing separation or cracking at the interface (bonding surface). Also, improvement in bonding strength due to relaxation of thermal stress can be expected. (2) A slit is provided on the surface to be bonded to the metal as a three-dimensional fiber-reinforced heat-resistant composite material in a direction perpendicular to the bonding surface,
Cutting the fiber in the direction of the joint surface, increasing the coefficient of thermal expansion in the direction of the joint surface of the three-dimensional fiber reinforced heat-resistant composite material, adjusting the coefficient of thermal expansion to match the coefficient of thermal expansion of the metal to be joined, and forming a gap in the joint surface and its vicinity Not only reduces the difference in thermal expansion between the three-dimensional fiber-reinforced heat-resistant composite material and the metal to be joined, but also allows the brazing material to penetrate well into the voids, resulting in separation or cracking at the interface (joining surface). The three-dimensional fiber reinforced heat-resistant composite material can be brazed to the metal without the occurrence of cracks. Also, improvement in bonding strength due to relaxation of thermal stress can be expected. (3) As a three-dimensional fiber reinforced heat-resistant composite material, one surface that is not bonded to metal exhibits relatively isotropic properties and has high strength and a low coefficient of thermal expansion. Bonding can be performed using a metal and a brazing material that are high and have similar thermal expansion coefficients. (4) The three-dimensional fiber-reinforced heat-resistant composite material and the metal can be brazed and joined by a simple method, and the application to an aerospace engine, a general-purpose gas turbine, and the like can be expected.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional configuration diagram showing a case where a method for joining a heat-resistant fiber-reinforced composite material for metal joining according to a first embodiment of the present invention is performed.

FIG. 2 is a schematic cross-sectional configuration diagram showing a case where a method of joining a heat-resistant fiber-reinforced composite material for metal joining according to a second embodiment of the present invention is performed.

FIG. 3 is a schematic cross-sectional configuration diagram showing a case where a conventional method for joining a heat-resistant fiber-reinforced composite material for metal joining is performed.

[Explanation of symbols]

 10, 16 Carbon fiber reinforced composite material (C / C material) 12, 24 Brazing material 14, 22 Metal 18 X, Y direction thread 20 Z direction thread 26 Slit

──────────────────────────────────────────────────続 き Continued on the front page (56) References Patent 2699443 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) D03D 13/00 C04B 35/83, 37/02

Claims (8)

(57) [Claims] 1. The three-dimensional fiber-reinforced heat-resistant composite material has a reduced fiber content in a bonding surface direction at and near a surface to be bonded to a metal, and an increased coefficient of thermal expansion in the bonding surface direction of the three-dimensional fiber-reinforced heat-resistant composite material. A three-dimensional fiber content adjusted fabric characterized by being adjusted. 2. The method according to claim 1, wherein at least one of expanding a spacing in a thickness direction of the fiber with respect to the bonding surface in the bonding surface direction and reducing a number of fibers per fiber bundle in the bonding surface direction. The fiber content-adjusted three-dimensional woven fabric according to claim 1, wherein the fiber content in the joining surface direction is reduced. 3. A fiber content ratio in a joining surface direction by performing at least one of increasing the number of fibers per fiber bundle in the thickness direction of the fibers with respect to the joining surface, and / or increasing the number of fiber bundles. The three-dimensional woven fabric according to claim 2, wherein the three-dimensional fiber content is adjusted. 4. A heat-resistant fiber-reinforced composite material for metal bonding, having a structure of the three-dimensional woven fabric having a controlled fiber content according to claim 1. 5. A three-dimensional fiber-reinforced heat-resistant composite material, wherein a surface to be bonded to a metal is provided with a slit in a direction perpendicular to the bonding surface, and the fiber in the bonding surface direction is cut to form a three-dimensional fiber-reinforced heat-resistant composite material. Increased coefficient of thermal expansion in the joint direction
A heat-resistant fiber-reinforced composite material for metal joining, which is adjusted and has an increased gap at and near a joining surface. 6. A surface of the heat-resistant fiber-reinforced composite material for metal bonding according to claim 4, wherein a slit is provided in a direction perpendicular to the bonding surface to cut the fiber in the direction of the bonding surface, and the metal is bonded. A heat-resistant fiber-reinforced composite material for metal bonding, in which the coefficient of thermal expansion in the bonding surface direction of the heat-resistant fiber-reinforced composite material for use is increased and adjusted, and the voids at and near the bonding surface are increased. 7. The three-dimensional fiber-reinforced heat-resistant composite material has a lower fiber content in a bonding surface direction at and near a surface to be bonded to a metal, and a thermal expansion coefficient in a bonding surface direction of the three-dimensional fiber-reinforced heat-resistant composite material increases. A fiber content adjusted three-dimensional fabric adjusted to match the coefficient of thermal expansion of the metal to be bonded is manufactured, and the heat-resistant fiber reinforced composite material for metal bonding manufactured using the fabric is brazed to the metal. Joining method of heat-resistant fiber reinforced composite material for metal joining. 8. A three-dimensional fiber-reinforced heat-resistant composite material, which is provided with a slit in a direction perpendicular to the bonding surface on a surface to be bonded to a metal as the three-dimensional fiber-reinforced heat-resistant composite material, and cuts fibers in the direction of the bonding surface. A fiber content-adjusted three-dimensional woven fabric in which the coefficient of thermal expansion in the direction of the joint surface is increased and adjusted to match the coefficient of thermal expansion of the metal to be joined and the voids in the joint surface and the vicinity thereof are increased, and the woven fabric is manufactured. A method for joining a heat-resistant fiber-reinforced composite material for metal bonding, comprising brazing a heat-resistant fiber-reinforced composite material for metal bonding manufactured by using the method to a metal.