JP4524591B2 - Composite material and manufacturing method thereof - Google Patents

Description

  The present invention relates to a metal-based composite material, and more particularly to a composite material of a light metal and an iron-based metal sintered body.

  Composite materials made by combining dissimilar constituent materials become materials with various characteristics that cannot be achieved with conventional materials by changing the types and volume ratios of constituent materials. It is extremely useful.

One of the metal-based composite materials whose base material is a metal, a composite part composed of a sintered body obtained by sintering metal powder and a metal impregnated and solidified in the pores, and at least one surface of the composite part There is a composite material composed of a metal part made of the above-described metal. In a composite material having the above structure, cracks may occur at the interface between the composite part and the metal part due to the difference in thermal expansion between the composite part and the metal part during rapid cooling after heat treatment of the composite material. There is. In particular, a composite material composed of an iron-based sintered body and a light metal such as an aluminum alloy is used in various fields, but has a large difference in thermal expansion between the iron-based metal and the light metal (for example, 11 to 11 for steel). about 12 × 10 ^-6 / K, about 20~25 × 10 ^-6 / K in the aluminum alloy), the cracks are likely to occur from the interface between the composite portion and the metal portion.

Therefore, in Patent Document 1, in a composite material composed of a composite part composed of an iron-based sintered body and an aluminum alloy impregnated and solidified in the pores thereof, and a base material part composed of the aluminum alloy, A composite material in which the difference in thermal expansion at the interface with the material part is 5 × 10 ⁻⁶ / K or less is disclosed. Specifically, among the iron-based sintered bodies, a sintered body located on the interface side between the base material portion and the composite portion is formed of stainless steel particles, and the thermal expansion difference at the interface is 5 × 10 ^−6. / K or less ensures crack resistance. However, in the composite material disclosed in Patent Document 1, the particles used for the sintered body on the interface side of the composite part are particles made of a material such as stainless steel having a relatively high coefficient of thermal expansion among ferrous metals. Therefore, combinations of materials that can be used are limited.

Further, in Patent Document 2, one surface layer is a dense layer, and a sintered body made of ceramic particles having a porous layer whose porosity gradually increases from the surface layer toward the other surface layer, and the pores of the sintered body are impregnated. A ceramic-metal composite comprising a solidified metal is disclosed. In the composite of Patent Document 2, the coefficient of thermal expansion of the metal is higher than the coefficient of thermal expansion of the ceramic. Therefore, by gradually decreasing the volume ratio of the sintered body from the surface layer toward the other surface layer, The coefficient of thermal expansion is gradually increased. However, a normal sintered body using particles has a limit in reducing the volume ratio of the sintered body. Therefore, it is difficult to make the thermal expansion coefficient of the composite closer to the thermal expansion coefficient of the metal. For example, when the heat dissipation layer made of the metal is formed on the other surface layer side of the composite (Examples 2, 4, and 8, 10), it does not reach the point of preventing cracks generated at the interface between the composite and the heat dissipation layer due to the difference in thermal expansion.
JP-A-8-229663 JP 2001-105124 A

  Therefore, the present inventors, in a composite material having a large difference in thermal expansion at the interface, use a fibrous material that is easy to control the volume ratio in place of a sintered body using particles, thereby enabling a difference in thermal expansion at the interface. I came up with the idea that can be made the optimal value.

  That is, in view of the above problems, an object of the present invention is to provide a composite material that has a novel configuration and can prevent the occurrence of cracks due to the difference in thermal expansion at the interface.

The composite material of the present invention is a first composite part comprising a sintered body made of iron-based metal particles, and a light metal impregnated and solidified in the pores of the sintered body,
Is integrally formed on at least one surface of the first composite section, whiskers, located on the surface of the sintered body What sintered fiber material der molded by sintering one or more of the short fibers and long fibers And a light metal of the same kind as the light metal impregnated and solidified in the fiber material to form the first composite part , and the volume ratio of the sintered body in which the volume ratio of the fiber material occupies the first composite part A second composite part lower than the rate,
A light metal part formed integrally with the first composite part via the second composite part, and made of the same kind of light metal as the light metal constituting the first composite part and the second composite part ;
The thermal expansion coefficient of the second composite part is an intermediate value between the thermal expansion coefficient of the first composite part and the thermal expansion coefficient of the light metal part.
At this time, it is desirable that the light metal of the first composite part, the second composite part, and the light metal part is integrally impregnated and solidified in the sintered body and the fiber material.

Here, the whisker and the short fiber are assumed to have, for example, an aspect ratio (the ratio of the length to the diameter) of 10 or more, and are different in shape from the iron-based metal particles forming the sintered body. .
In addition, the whisker, the short fiber, and the long fiber may be made of a material whose thermal expansion coefficient is lower than that of the light metal, and more preferably less than the thermal expansion coefficient of the iron-based metal particles. It consists of materials.

The method for producing a composite material of the present invention is a fiber that is a sintered fiber material obtained by forming and sintering one or more of whiskers, short fibers, and long fibers on at least one surface of a sintered body made of iron-based metal particles. The composite material of the present invention is produced by placing the material and then impregnating and solidifying the sintered body and the fiber material with light metal.
The method of producing a composite material of the present invention, together with the iron-based metal particles, whiskers, and one or more of the short fibers and long fibers, a sintered to the sintered body and the sintered fiber material light metals by impregnating solidified to prepared sintered body after and the sintered fiber material, characterized by producing a composite material of the present invention.

  In the composite material of the present invention, the difference in coefficient of thermal expansion between the first composite part and the light metal part is large. Therefore, by integrally forming the light metal part and the first composite part through the second composite part having the above configuration, the difference in thermal expansion between the first composite part and the light metal part is alleviated, and crack resistance is improved. It is improving. At this time, when a fiber material is used for the second composite part, it is easy to control the volume ratio of the fiber material, so that the thermal expansion coefficient of the second composite part can be set to an optimum value.

  And, in order for the thermal expansion coefficient of the second composite part to be an intermediate value between the thermal expansion coefficient of the first composite part and the thermal expansion coefficient of the light metal part, the whisker, short fiber and long fiber constituting the fiber material Since it only needs to be made of a material whose thermal expansion coefficient is lower than that of light metal, a wide variety of materials can be used. In particular, if it is made of a material having a thermal expansion coefficient equal to or lower than that of the iron-based metal particles, the crack resistance of the composite material can be improved satisfactorily.

Hereinafter, the best mode for carrying out the composite material and the method for producing the same according to the present invention will be described with reference to FIGS.

  The composite material of the present invention is formed integrally with the first composite part, the second composite part integrally formed on at least one surface of the first composite part, and the first composite part via the second composite part. And a light metal part.

  The first composite part, the second composite part, and the light metal part are appropriately arranged in accordance with the member using the composite material as long as at least the first composite part and the light metal part are integrally formed via the second composite part. Should be selected. For example, as shown in FIG. 1 (right figure) and FIG. 2 (right figure), the first composite part 1, the second composite part 2, and the light metal part 3 are laminated one another, as shown in FIG. Thus, the first composite part 1 may be positioned so as to be surrounded by the light metal part 3.

  The first composite part is composed of a sintered body made of iron-based metal particles, and a light metal impregnated and solidified in the pores of the sintered body.

  The sintered body is not particularly limited as long as it is a sintered body produced by a general method. The iron-based metal particles may be particles that have been conventionally used in sintered bodies, and usually have a particle size of 10 to 300 μm and a spherical shape or a shape close to a spherical shape. These particles are obtained, for example, by various atomizing methods or pulverizing methods. And as an iron-type metal particle, various alloy steel particles (for example, SKD type, SKH type etc.), cast iron particles, carbon steel particles, etc. other than pure iron particles can be used.

  In addition, the sintered body has a porosity (a volume ratio [%] of pores per volume of the sintered body, hereinafter referred to as Vp) and a pore diameter such that light metal is impregnated and solidified in the pore portion. If it is. If a sintered body having a high porosity or coarse pores is used, the strength of the sintered body decreases, and depending on the method of impregnating the sintered body with light metal, the sintered body may be damaged, which is not preferable. . Therefore, the sintered body preferably has a volume ratio (Vf = 100−Vp [%]) of 50% or more, and more preferably 60 to 90%.

  The light metal is impregnated and solidified in the pores of the sintered body, but the kind of light metal is not particularly limited as long as the sintered body does not melt or deteriorate when the sintered body is impregnated with the light metal. . For example, a light metal having a melting point lower than that of an iron-based metal constituting the iron-based member is easy to manufacture. Specifically, pure aluminum and aluminum alloys such as aluminum alloys containing Mg, Cu, Zn, Si, Mn, etc., magnesium alloys containing pure magnesium, Zn, Al, Zr, Mn, Th, rare earth elements, etc. Of these, magnesium-based metals are preferred. The light metal impregnated and solidified in the sintered body in the first composite part, the light metal holding the fiber material (described later) in the second composite part, and the light metal constituting the light metal part are the same kind of light metal.

  The second composite part is composed of a fiber material made of one or more of whiskers, short fibers, and long fibers (described as “whiskers etc.”) and a light metal that holds the fiber material.

  In the composite material of the present invention, the difference in thermal expansion between the first composite part having the above-described configuration and the light metal part made of light metal is large. Therefore, the second composite part relaxes the difference in thermal expansion between the first composite part and the light metal part, thereby improving crack resistance. At this time, since the volume ratio of the fiber material can be easily controlled by using the fiber material for the second composite part, the coefficient of thermal expansion of the second composite part can be set to an optimum value. The reason will be described below.

In addition, the coefficient of thermal expansion of the second composite part is an “optimum value”, and the coefficient of thermal expansion of the second composite part is an intermediate value between the coefficient of thermal expansion of the first composite part and the coefficient of thermal expansion of the light metal part. The coefficient of thermal expansion is inclined in the order of the first composite part, the second composite part, and the light metal part. If the coefficient of thermal expansion of the second composite part is an optimum value, cracks occurring in the composite material due to the difference in thermal expansion can be prevented satisfactorily. In particular, if the difference in thermal expansion between the second composite portion and the light metal portion is 6 × 10 ⁻⁶ / K or less, the occurrence of cracks can be further prevented.

  For example, the composite material disclosed in Patent Document 1 uses a sintered body that is granulated by a water atomization method or a pulverization method and formed by sintering particles having a particle size of about 20 to 180 μm. . However, the particles granulated by the above method are difficult to be molded with a low volume ratio, and even if a sintered body with a low volume ratio is produced, depending on the method of impregnating the light metal, the sintered body may be There is a risk of damage. On the other hand, fibrous materials such as whiskers have a lower bulk density than particulate materials when compared with the same material. Therefore, in the case of a fiber material made of whisker or the like, the volume ratio is less likely to be larger than in the case of particles (for example, if it is a general whisker, Vf = 33% at the maximum).

  Therefore, the whisker or the like used for the fiber material does not necessarily need to be a material having an intermediate thermal expansion coefficient value between the ferrous metal and the light metal, and at least a material having a thermal expansion coefficient lower than that of the light metal. Then, when it is set as a composite material, the thermal expansion coefficient of a 2nd composite part does not fall too much, and an optimal value can be ensured. In particular, if it is made of a material having a thermal expansion coefficient equal to or lower than that of the iron-based metal particles, it is easy to set the thermal expansion coefficient of the second composite part to an optimum value.

  As a specific example, suppose that a sintered body made of iron-based metal particles is used for the first composite part, and a fiber material made of iron-based metal short fibers having the same composition is used for the second composite part. In this case, there is no difference in the thermal expansion coefficient between the particles and the short fibers, but the iron-based short fibers have a lower bulk density than that in the particle state. Therefore, unless the volume ratio of the sintered body is reduced by a special method, the volume ratio of the fiber material is lower than the volume ratio of the sintered body. As a result, even when an iron-based metal having the same thermal expansion coefficient is used, the thermal expansion coefficient of the second composite portion can be set to an optimum value.

  The volume ratio of the fiber material is not limited, and after impregnating and solidifying the light metal, if the thermal expansion coefficient of the second composite part is lower than the thermal expansion coefficient of the light metal part as a result Good. If an optimal range is given, when using pure iron powder as the sintered material, aluminum borate whisker as the fiber material, and aluminum alloy as the light metal, the volume ratio of the sintered body is 50 to 80%, The crack which generate | occur | produces in a composite material as the volume ratio of a fiber material is 15 to 30% can be prevented effectively.

  The fiber material is a heat-resistant fiber material having a heat resistance to the extent that there is no change in characteristics when the fiber material is impregnated with a light metal, or when the composite material of the present invention is heat-treated or used at a high temperature. It is good.

As the types of whiskers and the like constituting the fiber material, it is preferable to use ceramic or metal-based whiskers, short fibers, or long fibers. In the case of ceramic whiskers, it is preferable to use aluminum borate whiskers. Besides, silicon carbide (SiC) whiskers, alumina (Al ₂ O ₃ ) whiskers, silicon nitride (Si ₃ N ₄ ) whiskers, boron carbide (B ₄ C) ) Whisker etc. can be used. Moreover, a metal whisker may be sufficient. As the ceramic fibers, long fibers and short fibers such as alumina fibers and alumina silica fibers can be used. As the metal fiber, a long fiber or a short fiber made of an iron-based fiber such as pure iron fiber, stainless steel fiber, or cast iron fiber can be used. Further, it may be a carbon fiber long fiber or short fiber subjected to heat treatment such as BN coating. At this time, a combination having excellent chemical compatibility between the fiber material and the light metal may be appropriately selected and used.

  In addition, it is preferable that the aspect ratio of the whisker and the short fiber constituting the fiber material is 10 or more. In addition, it is preferable to use a general whisker having a diameter of about 1 μm for a whisker and about several μm for a short fiber or a long fiber.

  The composite material of the present invention is preferably manufactured by casting. In particular, casting methods such as a high pressure casting method and a molten metal infiltration method are suitable. According to these casting methods, the sintered body and the fiber material can be impregnated with a melt of light metal in a state close to non-porous. Further, a method of casting while applying pressure is desirable, and adhesion between the sintered body and the fiber material (that is, the interface between the first composite part and the second composite part) is improved by pressurization at the time of casting. Cracks from the interface between the first composite part and the second composite part are less likely to occur. And if it manufactures by casting, a light metal part made of light metal is formed while impregnating a molten metal of light metal into a sintered body and a fiber material in a casting mold, and then the molten metal of light metal is solidified. The part, the second composite part, and the light metal part can be integrally formed.

  In this case, the fiber material is a sintered body ("sintered") in which whisker or the like is used in the form of a fiber, and at least one of whisker, short fiber, and long fiber is previously formed into a desired shape and sintered. It may be referred to as “fiber material”. For example, as shown in FIG. 1, fibrous whiskers or the like 2 ′ are deposited in a desired shape on a desired surface of a sintered body 1 ′ made of iron-based metal particles, and then impregnated and solidified with a light metal 3 ′, or The first composite part 1 is passed through the second composite part 2 by a method in which the sintered body 1 ′ and the sintered fiber material 2 ′ are produced in separate steps, and both are brought into close contact with each other and then impregnated and solidified with the light metal 3 ′. And a composite material in which the light metal portion 3 made of the light metal 3 ′ is integrally formed. In addition, since the fiber material is used, the volume ratio can be set to a desired value even if only whiskers or the like are deposited.

In addition to the above method, whisker or the like is deposited on a desired surface of the sintered body and integrally sintered, the sintered body and the sintered fiber material are closely adhered, or sintered, or A sintered body and a fiber material joined together by a method in which iron-based metal particles and whiskers are arranged at desired positions to simultaneously form a sintered body and a sintered fiber material (joint-type sintered material) It is also possible to impregnate and solidify a light metal. Since the sintered body and the fiber material are integrally sintered, the sintered body and the fiber material can be strongly bonded, and as a result, the adhesion at the interface between the first composite part and the second composite part is improved. , Cracks from the interface between the first composite part and the second composite part are less likely to occur. In particular, when iron-based fibers are used as the fiber material, the sintered body and the fiber material are made stronger by integrally sintering the iron-based metal particles or the sintered body thereof and the iron-based fiber. Can be joined.

  In the sintered body made of particles, pores opened on the surface of the sintered body are likely to be clogged due to friction at the time of mold release after sintering, but the sintered fiber material made of whisker or the like having a certain length Then, since the volume ratio at the time of molding is low, the friction with the mold becomes small, and the above-described phenomenon hardly occurs. Therefore, since the sintered fiber material has a rough surface, when the first composite part, the second composite part, and the light metal part are integrally formed, the bonding with each interface is good and the adhesiveness is excellent. It is difficult for cracks to form. As a result, the effect of preventing cracks at the interface due to the difference in thermal expansion is improved.

  Moreover, if a nonwoven fabric is used as the fiber material, the second composite portion can be easily formed on a member having a shape in which the fiber material is difficult to be disposed at a desired position or a member having a complicated shape. For example, as shown in FIG. 2, a case of a hollow cylindrical member that is formed so that the second composite portion is located at the center in the thickness direction will be described. A cylindrical sintered body 1 ′ formed in advance and coaxially with the cylindrical jig 4 is sintered in the mold 40 in a state where the nonwoven fabric 2 ′ is coated so as to be in close contact with the outer peripheral surface. Installed. Thereafter, a molten metal of light metal is poured into the mold 40, and the sintered body 1 ′ and the nonwoven fabric 2 ′ are integrally impregnated and solidified with the light metal, whereby the first composite part, the second composite part, the light metal part, A composite material is obtained which is a laminate in which the members are laminated in the thickness direction of the hollow cylindrical member (right diagram in FIG. 2). As an example of the composite material of the present invention, as shown in FIG. 3, a composite material in which a part of the first composite part 1 is surrounded by the second composite part 2 and the light metal part 3 can be considered. A nonwoven fabric can also be used when forming a composite material having such a cross section.

  By using a non-woven fabric as the fiber material as described above, there is no need to sinter the fiber material to produce a sintered fiber material. In addition, the shape is complicated, the sintered body and the sintered fiber material cannot be molded at once (when the mold needs to be divided), or the sintered body and the fiber material are difficult to adhere to each other Even if it is this member, since a nonwoven fabric should just be stuck to the part of the sintered compact which wants to form a 2nd composite part, it is a simple method.

  Note that “adhering” the sintered body and the fiber material (nonwoven fabric) means that when the sintered body and the fiber material are impregnated with light metal, the interface between the two is not formed with a portion consisting only of the light metal. What is necessary is just to be in the state.

  Since the composite material of the present invention having the above-described configuration has high strength and is lightweight, it can be suitably used for various parts such as an engine block, a hydraulic pump, and a compressor. Among these, in a compressor having a compression mechanism and a housing having a working space for compressing gas by the compression mechanism, it is desirable that at least a part of the housing and the cylinder is a compressor made of the composite material of the present invention. A compressor in which a housing and a cylinder are formed of the composite material of the present invention is a compressor that is lightweight, excellent in pressure resistance and heat resistance. Furthermore, even if heat treatment is performed for tempering the light metal part or the sintered body, cracks that occur during quenching and the like are prevented.

  When the composite material of the present invention is used as a housing of a compressor, it is desirable to use an aluminum metal or a magnesium metal as a light metal. Moreover, it is desirable that the sintered body of the first composite portion has a volume ratio Vf = 60 to 90% from the viewpoint of maintaining strength.

  In the composite material of the present invention, in a substantially hollow cylindrical housing, it is desirable that the first composite part, the second composite part, and the light metal part are laminated in the thickness direction to form a laminate. That is, a housing formed so that the first composite portion is located on the inner side surface portion and the light metal portion is located on the outer side surface portion (see FIG. 2), the light metal portion is disposed on the inner side surface portion and the outer surface portion, and the first composite portion is disposed on the central portion. It is preferable that the housing is formed so as to be positioned. In addition, the housing may be arranged such that the first composite portion is located only in a portion where the pressure resistance is particularly required (for example, FIG. 3 is a part of the cross section in the axial direction or the axial direction). .

  In addition, the composite material of this invention is not limited to said embodiment, You may add another structure. For example, when the difference in thermal expansion between the first composite part and the second composite part is large, a third composite part is provided at the interface between the first composite part and the second composite part, and the thermal expansion coefficient is inclined. Also good.

Below, the Example of the composite material of this invention and its manufacturing method is described.

[Preparation of thermal expansion measurement specimen]
Iron-based metal particles (Atomized iron powder (pure iron powder) KIP300A manufactured by JFE Steel Co., Ltd .: particle size 45 to 180 μm) and aluminum borate (9Al ₂ O ₃ .2B ₂ O ₃ ) whisker (Shikoku Chemical Industries, Ltd.) Arbolex: fiber diameter 0.5 to 1.0 μm, fiber length 10 to 30 μm) was prepared.

  Iron-based metal particles and aluminum borate whiskers were each molded into a predetermined shape and sintered at a predetermined temperature to prepare a preform. Table 1 shows the volume ratio of the produced preform. Then, the preform was placed at a predetermined position of the cavity of the high-pressure casting mold, and a molten aluminum alloy (A2024) was injected into the cavity and pressurized with a casting pressure of 100 MPa. Thus, each preform was impregnated and solidified with an aluminum alloy to obtain thermal expansion measurement test pieces corresponding to the first composite part (two types) and the second composite part of the composite material.

  Further, a thermal expansion measurement test piece corresponding to the light metal part of the composite material was obtained in the same manner as the above procedure except that no preform was used.

  And about the produced thermal expansion measurement test piece, when changing temperature from 50 degreeC to 200 degreeC, each thermal expansion coefficient was measured by detecting a displacement with a quartz push rod type | formula. The measurement results are shown in Table 1.

According to the above test, the difference in thermal expansion between the first composite part and the light metal part is 10 × 10 ⁻⁶ / K or more, but the difference in thermal expansion between the second composite part and the light metal part is 5.2 × 10 ^{− 6} / K. Therefore, when the first composite part and the light metal part are formed as a composite material integrally formed via the second composite part, the second composite part reduces the thermal expansion difference between the first composite part and the light metal part. Thus, it is possible to prevent the occurrence of cracks due to the difference in thermal expansion.

  In addition, the preform made of the iron-based metal particles and the preform made of aluminum borate whisker are laminated and adhered, and the preform is impregnated with a molten aluminum alloy by a high-pressure casting method, and aluminum borate By forming a light metal part made of an aluminum alloy on the whisker side (second composite part side), the composite material of the present invention can be obtained. At this time, the thickness of the second composite part was about 5 mm. In addition, if the thickness of a 2nd composite part is 1-10 mm, it is applicable.

It is a schematic diagram which shows the composite material of this invention, Comprising: It is sectional drawing before impregnation of a light metal (left figure) and after impregnation solidification (right figure). It is a schematic diagram which shows the member of hollow cylindrical shape formed with the composite material of this invention, Comprising: In axial sectional view before impregnation of light metal (left figure), and axial center direction sectional view after impregnation solidification (right figure) is there. It is sectional drawing which shows an example of the composite material of this invention typically.

Explanation of symbols

1: 1st composite part 2: 2nd composite part 3: Light metal part 1 ': Sintered body 2' (consisting of iron-based metal particles): Fiber material 3 ': Light metal

Claims (14)

A first composite part composed of a sintered body made of iron-based metal particles, and a light metal impregnated and solidified in the pores of the sintered body,
Is integrally formed on at least one surface of the first composite section, whiskers, located on the surface of the sintered body What sintered fiber material der molded by sintering one or more of the short fibers and long fibers And a light metal of the same kind as the light metal impregnated and solidified in the fiber material to form the first composite part , and the volume ratio of the sintered body in which the volume ratio of the fiber material occupies the first composite part A second composite part lower than the rate,
A light metal part formed integrally with the first composite part via the second composite part, and made of the same kind of light metal as the light metal constituting the first composite part and the second composite part ;
The thermal expansion coefficient of the second composite part is an intermediate value between the thermal expansion coefficient of the first composite part and the thermal expansion coefficient of the light metal part. Wherein the first composite section, the second composite section and the light metal part, the light metal and the iron-based metal particles or the sintered body, the whiskers, wherein the one or more or the of the short fibers and the long fibers The composite material according to claim 1 , wherein the sintered fiber material is impregnated and solidified in a joining-type sintered material obtained by integrally sintering the sintered fiber material to form a laminated body laminated together.   The composite material according to claim 1, wherein the light metal is an aluminum-based metal or a magnesium-based metal.   The composite material according to claim 1, wherein the fiber material is a heat-resistant fiber material having heat resistance.   The composite material according to claim 1, wherein the whisker and the short fiber have an aspect ratio of 10 or more.   The composite material according to claim 1, wherein the whisker, the short fiber, and the long fiber are made of a material having a thermal expansion coefficient lower than that of the light metal.   The composite material according to claim 1, wherein the whisker, the short fiber, and the long fiber are made of a material having a thermal expansion coefficient equal to or lower than a thermal expansion coefficient of the iron-based metal particles.   The composite material according to claim 1, wherein the whisker is a ceramic whisker.   The composite material according to claim 8, wherein the ceramic whisker is an aluminum borate whisker.   The composite material according to claim 1, wherein the short fibers or the long fibers are metal fibers or ceramic fibers. The fibrous material is a composite material of an iron-based fibers Tona Ru claim 1 made of an iron-based metal having the same composition as the iron-based metal particles.   The composite material according to claim 1, wherein the short fibers or the long fibers are carbon fibers. A fiber material, which is a sintered fiber material obtained by molding and sintering one or more of whiskers, short fibers, and long fibers, is disposed on at least one surface of a sintered body made of iron-based metal particles, and then sintered. A composite material according to claim 1 , wherein the composite material according to claim 1 is produced by impregnating and solidifying a light metal in the body and the fiber material. And iron-based metal particles, whiskers, and one or more of the short fibers and long fibers, sintered body and the sintering to sintered bodies and sintered fiber material from the produced integrally the The method for producing a composite material according to claim 1, wherein the composite material according to claim 1 is produced by impregnating and solidifying a sintered metal with a light metal.

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