JPH0353333B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to a carbonized carbon fiber having an inner layer and a surface, which are made of inorganic fibers with a rich color tone, carbon fibers, glass fibers, boron fibers, aramid fibers, and carbon. The present invention relates to a composite material reinforced with a hybrid fiber of at least one type of fiber selected from the group consisting of silicon fibers and having beautiful mechanical properties and color tone.

(Prior Art and its Problems) As a conventional reinforcing material, research is underway on hybrid fiber-reinforced composites in which two or more types of fibers are placed in a matrix in order to utilize the characteristics of various materials.

Research has been conducted on the above hybrid fibers, such as carbon/glass, carbon/aramid fiber, boron/carbon, boron/aramid fiber, boron/glass, ceramic fiber/aramid fiber, aramid fiber/glass, etc. , carbon/aramid fibers are overwhelmingly common, and actual applications are almost limited to these two types.

However, when carbon fibers are used, surface treatment of the fibers is required due to poor wettability with the matrix.Furthermore, even when surface-treated carbon fibers are used, the composite has low shear strength and is perpendicular to the fibers. Since the tensile strength in the direction is low, the matrix and fibers tend to separate easily, and the fatigue strength is low, and the bending impact value is low, making it easy to break, which is a practical problem. When glass fiber is used, a sufficient reinforcing effect cannot be obtained due to its low tensile strength and low elastic modulus. When using silicon carbide fibers having a core of boron fibers, they cannot be used for curved parts with complicated shapes because of their large diameters. When aramid fibers are used, they are weak against compression and have low fatigue strength.

In addition, conventional hybrid fibers are all white to black in color, so composites reinforced with these fibers have poor color, and it is necessary to coat the surface of the composite or add other resins to the composite. Unless laminated, it was not possible to obtain composites with a beautiful appearance and various color tones.

Metals or plastics reinforced with inorganic fibers can be used in products that require strength and lightness, such as
From tennis rackets, fishing rods, ski stocks, ski gear, racing cars, pipes, etc. to aircraft,
Used in a wide range of products including automobiles. For these uses, not only mechanical strength but also beautiful appearance and fashionability are required as important factors. Conventionally known hybrid fibers cannot simultaneously satisfy the two requirements of sufficient mechanical strength and beautiful appearance.

(Objective of the Invention) An object of the present invention is to provide a hybrid fiber-reinforced composite having a beautiful color tone and improved wettability with metal or plastic serving as a matrix.

(Summary of the Invention) According to the present invention, a hybrid fiber of an inorganic fiber and at least one type of fiber selected from the group consisting of carbon fiber, glass fiber, boron fiber, aramid fiber, and silicon carbide fiber having a carbon core. In a hybrid fiber-reinforced composite with a plastic or metal matrix as a reinforcing material,
The inorganic fiber is () an amorphous material consisting essentially of Si, M, C and O, or () substantially consisting of β-SiC, MC, a solid solution of β-SiC and MC, and/or MC _1- Each crystalline ultrafine particle with a particle size of _X of 500 Å or less, and amorphous SiO ₂ and MO ₂
or () a mixed system of the amorphous substance mentioned in () above and the crystalline ultrafine particle aggregate mentioned in () above, made of inorganic fibers containing silicon, titanium or zirconium, carbon and oxygen. an inner layer, () an amorphous material consisting essentially of Si, M and O, () an aggregate consisting of crystalline SiO ₂ and MO ₂ , or () an amorphous substance of () above and () ) mixed system of crystalline polymers (where M in the above formula represents Ti or Zr, and x is 0
A number greater than 1 and less than 1. ) and a surface layer of an inorganic material containing silicon, titanium or zirconium, and oxygen, optionally containing up to 5% by weight of carbon.

(Detailed Description of the Invention) In the present invention, the inner layer that occupies most of the inorganic fibers that are the constituent parts of the hybrid fiber is () an amorphous material consisting essentially of Si, M, C, and O, or ( ) Substantially each crystalline ultrafine particle of β-SiC, MC, a solid solution of β-SiC and MC and/or MC _1-X with a particle size of 500 Å or less, and amorphous SiO ₂ and MO ₂
or () a mixed system of the amorphous substance of the above () and the crystalline ultrafine particle aggregate of the above (), (M: Ti or
It is made of inorganic fibers containing silicon, titanium or zirconium, carbon and oxygen, Zr, 0<x<1).

In addition, the surface layer of the inorganic fiber is () an amorphous material substantially consisting of Si, M, and O, () an aggregate consisting of crystalline SiO ₂ and MO ₂ , or () the above () An inorganic substance containing silicon, titanium or zirconium, oxygen, and optionally 5% by weight or less of carbon, consisting of a mixed system (M: Ti or Zr) of an amorphous substance and a crystalline polymer as described above. There is.

The above-mentioned inorganic fibers can be obtained, for example, by first preparing inorganic fibers having the same composition as the inner layer and then heating this fiber in an oxidizing atmosphere to form a surface layer.

Inorganic fibers having the same composition as the inner layer can be prepared, for example, according to the method described in US Pat. No. 4,347,347 and US Pat. No. 4,359,559. An example of its preparation is shown below.

Mainly expression (However, R in the formula represents a hydrogen atom, a lower alkyl group, or a phenyl group.)
~10,000 polycarbosilane, and represented by the formula MX ₄ (where M in the formula represents Ti or Zr, and X represents an alkoxy group, phenoxy group, or acetylacetoxy group having 1 to 20 carbon atoms). The ratio of the total number of (-M- _O )- structural units of the organometallic compound is 2:1 to 200. :In addition to the quantitative ratio within the range of 1,
A heating reaction is performed in an atmosphere inert to the reaction, and at least a portion of the silicon atoms of the polycarbosilane are bonded to the metal atoms of the organometallic compound via oxygen atoms, so that the number average molecular weight is about
700 to 100,000 organometallic polymers are produced.
A second step of preparing and spinning a spinning dope of the organometallic polymer; a third step of infusibleizing the spun fibers under tension or no tension; The fourth step of firing at a temperature in the range of 1800°C substantially converts silicon,
Inorganic fibers made of titanium or zirconium, carbon and oxygen can be produced.

The proportion of each element in the inorganic fiber is usually Si: 30 to 60% by weight, Ti or Zr: 0.5 to 35% by weight, preferably 1 to 10% by weight.
% by weight, C: 25-40% by weight, O: 0.01-30% by weight.

The inorganic fibers obtained in this way are usually heated at 500 to 1600℃.
By heating in an oxidizing atmosphere at a temperature in the range of , a surface layer is formed and the inorganic fiber of the present invention is obtained. Oxidizing atmospheres include air,
Examples include atmospheres such as pure oxygen, ozone, water vapor, and carbon dioxide gas.

This treatment imparts various colors to the inorganic fibers, such as red, purple, blue, green, orange, brown, and peach. The color tone of the inorganic fiber can be arbitrarily changed by changing the heating conditions in an oxidizing atmosphere and adjusting the thickness and structure of the surface layer. For example, when the oxidation conditions are mild, the color becomes red or purple, and as the oxidation conditions are made more severe, the color becomes blue or green. Adjustment of color tone can be readily accomplished by those skilled in the art in accordance with the above teachings.

The proportions of each element in the inner layer of the continuous inorganic fiber thus obtained are substantially the same as above, and the proportions of each element in the surface layer are usually Si: 20-65% by weight, O: 30-55% by weight, Ti or Zr: 0.3 to 40% by weight, preferably 1 to 15
% by weight, C: 0 to 5% by weight.

The diameter of the inner layer of continuous inorganic fibers in the present invention is usually 2 to 20 μm, and the surface area thickness is usually 0.01 μm.
~5μm.

These inorganic fibers can be produced using methods that orient the fibers themselves in uniaxial or multiaxial directions, or by methods such as plain weave, satin weave,
There are methods of using it in various patterned textiles such as patterned weaving, twill weaving, leno weaving, spiral weaving, three-dimensional weaving, etc., and methods of using it as chopped strand fiber.

The proportion of inorganic fibers in the hybrid fiber is preferably 10% or more, particularly 20% or more. If the proportion of inorganic fibers is too small, the effects of improving mechanical properties, which are the objectives of the present invention, such as improving the bond strength between the inorganic fibers and the matrix, improving reinforcing efficiency, and reducing the fatigue strength reduction rate, will be insufficient. .

Looking at the hybrid state of hybrid fibers by form, there are (1) interlayer hybrids in which a layer of one type of fiber and a layer of another type of fiber are laminated, and (2) intralayer hybrids that have already been hybridized within one layer. There are basically two types of hybrids, and (3) there are also combinations of them.
There are six main types of combinations:

(a) Laminated single-layer tape (layers of different fibers are alternately layered) (b) Sandwich type (layers of different fibers are layered in a sandwich) (c) Rib reinforcement (d) Blended tow (Hybrid of different fibers in each single fiber unit) (e) Lamination of mixed tape (Hybrid of different fibers in each yarn unit) (f) Mixed surface layer Next, in the present invention, the matrix Examples of metals constituting the metal include aluminum, magnesium, titanium, and alloys thereof.

Examples of plastic matrices include epoxy resin, modified epoxy resin, polyester resin, polyimide resin, phenolic resin, polyurethane resin, polyamide resin, polycarbonate resin, silicone resin, phenoxy resin, polyphenylene sulfide resin, and fluorine resin. Resin, hydrocarbon resin, halogen-containing resin, acrylic acid resin, ABS
Examples include resin, ultra-high molecular weight polyethylene, modified polyphenylene oxide, and polystyrene.

There are no particular limitations on the method for producing the hybrid fiber-reinforced composite of the present invention, and the composite can be produced by methods known per se.

The metal composite is manufactured according to known methods for manufacturing metal composite materials, such as diffusion bonding, liquid infiltration, thermal spraying, electrodeposition, extrusion and hot rolling, chemical vapor deposition, or sintering. can do.

Methods for producing plastic composites include methods known per se, such as a hand lay-up method, a mated metal die method, a breakaway method, a filament winding method, a hot press method, an autoclave method, and a continuous drawing method.

The proportion of hybrid fibers in the reinforced composite of the invention is preferably 10 to 70% by volume, based on the composite. Even if the proportion of hybrid fibers is excessively high, the amount of matrix will be relatively small, and the gaps between the reinforcing fibers will not be able to be filled sufficiently with the matrix, and the strength according to the law of compounding will not be exhibited. It disappears. Furthermore, if the proportion of hybrid fibers is too low, it becomes difficult to obtain a composite with good mechanical properties.

In the present invention, the distribution of the hybrid fibers in the composite is controlled by attaching a dispersing material such as powder of a heat-resistant substance, short fibers, or whiskers to each fiber constituting the hybrid fibers or to the hybrid fibers themselves. It can be made uniform.

There are no particular restrictions on the method for depositing the above-mentioned dispersion material, and for example, electrodeposition, a method using a fluidized bed, a spraying method, a suspension dipping method, etc. can be employed. The suspension dipping method can be suitably employed from the viewpoints of simplicity and wide applicability.

An example of the suspension dipping method is to unwind inorganic fibers wound around a bobbin or a continuous inorganic fiber bundle made by bundling an appropriate number of inorganic fibers, or to immerse a woven inorganic fiber in a liquid in which a dispersant is suspended. An example is a method in which a dispersing material is attached to the surface of each of the inorganic fibers or the fibers of the textile. When dipping an inorganic fiber bundle or fabric with a large number of fibers, it is preferable to apply vibrations using ultrasonic waves to uniformly adhere the dispersion material to each fiber. The frequency of ultrasonic waves is conveniently about 10 to 2000 KHz.

The suspension may be water, but organic solvents such as ethanol, methanol, acetone are preferably used.

Further, the hybrid fiber of the present invention can be subjected to sizing treatment if necessary. As the sizing agent, all known sizing agents for inorganic fibers can be used, examples of which include polyethylene oxide, polystyrene oxide, polymethylene, polyvinyl alcohol,
Examples include epoxy resin.

(Example) Examples are shown below.

Manufacturing method of inorganic fiber [] Polydimethylsilane 100 synthesized by dechlorination condensation of dimethyldichlorosilane with metallic sodium
It has a main chain skeleton mainly composed of carbosilane units of the formula (-Si-CH ₂ )-, which is obtained by adding 3 parts by weight of polyborosiloxane per part by weight and thermally condensing it at 350°C in nitrogen, Titanium alkoxide is added to the polycarbosilane having a hydrogen atom and a methyl group on the silicon atom of the carbosilane unit, and cross-linking polymerization is carried out at 340°C in nitrogen to form 100 parts of the carboxylane unit with the formula (-Ti -O)- titanoxane
A polytitanocarbosilane consisting of 10 parts was obtained.
This polymer is melt-spun, infusible at 190°C in air, and then calcined at 1300°C in nitrogen, resulting in fibers with a diameter of 13 μm, a tensile strength of 310 Kg/mm ² , and a tensile modulus of 16 t/mm ² . , a precursor inorganic fiber with a titanium element content of 3% by weight was obtained, consisting of titanium, carbon, and oxygen. This fiber consists of an amorphous substance consisting of Si, Ti, C and O, a solid solution of β-SiC and TiC, crystalline ultrafine particles of TiC _1-X (0<x<1) with a particle size of 50 Å, and non-crystalline particles. It consisted of a mixed system of crystalline SiO ₂ and TiO ₂ aggregates.

By heating the above precursor inorganic fiber in air at 900° C. for 1 hour, a continuous inorganic fiber [ ] that emits bright blue reflected light was obtained. This continuous inorganic fiber [] has a fiber diameter of 13.2 μm and a tensile strength of 300 kg/
mm ² and a tensile modulus of 15.3 t/mm ² , and had an amorphous glass layer of 0.3 μm on the fiber surface.

Manufacturing method of inorganic fiber [] Continuous inorganic fiber [] that emits green reflected light was obtained in the same manner as in Example 1 except that the precursor inorganic fiber was heat-treated in air at 1100° C. for 30 minutes. Continuous inorganic fiber [ ] has a fiber diameter of 13.3μm and a tensile strength of
It had mechanical properties of 298 Kg/mm ² and a tensile modulus of 15.1 t/mm ² , and had an amorphous glass layer of 0.4 μm on the fiber surface.

Manufacturing method of inorganic fiber [] Tetrakisacetylcetonatozirconium is added to 80 g of polycarbosilane obtained in the same manner as in the preparation of inorganic fiber [], and crosslinking polymerization is carried out at 350°C in nitrogen to produce 100 parts of carbosilane.
A polyzirconocarbosilane consisting of 30 parts of zirconosiloxane of the formula (-Zr-O)- was obtained. This polymer is dissolved in benzene and dry spun in air.
Infusible treatment at 170℃ followed by 1200℃ in nitrogen
The fiber diameter is 10μ, the tensile strength is 350Kg/ ^mm2 ,
An amorphous precursor inorganic fiber having an elastic modulus of 18 t/mm ² and a zirconium element content of 4.5% by weight, consisting mainly of silicon zirconium, carbon and oxygen, was obtained.

Continuous inorganic fibers that emit blue-violet reflected light were obtained by heat-treating the precursor inorganic fibers in air at 800°C for 1 hour. This continuous inorganic fiber [ ] has a fiber diameter of 10.2 μm, a tensile strength of 337 Kg/mm ² ,
It has mechanical properties with a tensile modulus of 17.2t/ ^mm2 ,
It had an amorphous glass layer of 0.4 μm on the fiber surface.

Example 1 Inorganic fibers [
A prepreg sheet was obtained by impregnating the mold) and pre-curing. Similarly surface-treated carbon fibers (polyacrylonitrile diameter, fiber diameter 7μ) were aligned in a uniaxial direction into a sheet, and impregnated with epoxy resin to obtain a prepreg sheet. The thus obtained inorganic fibers and carbon fiber prepregs were alternately laminated with the same axial direction and then hot pressed to produce a hybrid fiber reinforced epoxy composite.
The fiber content of this composite was 30% by volume of inorganic fibers and carbon fibers, respectively.

The obtained composite had a tensile strength of 163 Kg/mm ² , a tensile modulus of 10.7 t/mm ² , a bending strength of 98 Kg/mm ² , a flexural modulus of 7.9 t/mm ² , and an interlaminar shear strength of 11.2 Kg/mm ² ,
The bending impact value was 283 kg·cm/cm ² . This composite is the inorganic fiber that makes up the hybrid fiber []
It showed a beautiful color tone reflecting the bright blue reflected light emitted from it.

Example 2 A plain weave cloth was manufactured using the carbon fiber used in Example 1 for the warp and the inorganic fiber [ ] for the weft, and was impregnated with the epoxy resin used in Example 1 to obtain a prepreg sheet. The thus obtained prepreg sheets were laminated and hot pressed to produce a hybrid fiber-reinforced epoxy composite.

The obtained composite had a tensile strength of 89 Kg/mm ² , a tensile modulus of 7.2 t/mm ² , a bending strength of 83 Kg/mm ² , a flexural modulus of 7.2 t/mm ² , and an interlaminar shear strength of 10.9 Kg/mm ² , the bending impact value was 279Kg·cm/ ^cm2 . This composite exhibited a beautiful color tone reflecting the bright blue reflected light emitted from the inorganic fibers that make up the hybrid fiber.

Example 3 Inorganic fibers [] were aligned in a sheet shape in the uniaxial direction, impregnated with the epoxy resin used in Example 1, and precured to obtain a prepreg sheet.
Similarly, glass fibers (E-glass) were uniaxially aligned into a sheet shape and impregnated with the epoxy resin used in Example 1 to obtain a prepreg sheet. The thus obtained inorganic fiber [] and carbon fiber prepreg were laminated and hot pressed to produce a hybrid fiber-reinforced epoxy composite.

The obtained composite had a tensile strength of 93 Kg/mm ² , a tensile modulus of 8.1 t/mm ² , a bending strength of 87 Kg/mm ² , a flexural modulus of 7.1 t/mm ² , and an interlaminar shear strength of 9.8 Kg/mm ² , the bending impact value was 271Kg·cm/ ^cm2 . This composite exhibited a beautiful color tone reflecting the bright green reflected light emitted from the inorganic fibers that make up the hybrid fiber.

Example 4 An 8-ply satin cloth was manufactured using boron fibers with a fiber diameter of 100 μm for the warp and inorganic fibers for the weft, and was impregnated with the epoxy resin used in Example 1 to obtain a prepreg sheet. The thus obtained prepregs of inorganic fibers and boron fibers were laminated and hot pressed to produce a hybrid fiber-reinforced epoxy composite. The fiber content of this composite was 15% by volume of inorganic fibers and 45% by volume of boron fibers, for a total of 60% by volume.

The obtained composite had a tensile strength of 152 Kg/mm ² , a tensile modulus of 18 t/mm ² , a bending strength of 125 Kg/mm ² , a flexural modulus of 9.0 t/mm ² , an interlaminar shear strength of 13 Kg/mm ² , The bending impact value was 315 kg·cm/cm ² . This composite reflects the bright blue-purple reflected light emitted from the inorganic fibers that make up the hybrid fiber.
It showed a beautiful color tone.

Example 5 Silicon carbide fiber with carbon core wire having a fiber diameter of 140μ was used for the warp, and inorganic fiber [] was used for the weft.
A sheet satin woven cloth was produced and impregnated with the epoxy resin used in Example 1 to obtain a prepreg sheet. A prepreg of the thus obtained inorganic fiber [] and a silicon carbide fiber having a carbon core was laminated and hot pressed to produce a hybrid fiber reinforced epoxy composite. The fiber content of this composite is inorganic fiber [ ] 15% by volume, silicon carbide fiber
It was 45% by volume, 60% by volume in total.

The resulting composite had a tensile strength of 151 Kg/mm ² , a tensile modulus of 18.3 t/mm ² , a bending strength of 106 Kg/mm ² , a flexural modulus of 9.0 t/mm ² , and an interlaminar shear strength of 11.2 Kg/mm ² ,
The bending impact value was 286 kg·cm/cm ² . This composite is the inorganic fiber that makes up the hybrid fiber []
It showed a beautiful color tone reflecting the bright blue reflected light emitted from it.

Example 6 An 8-ply satin cloth was manufactured using aramid fiber (commercially available Kepler) for the warp and inorganic fiber [ ] for the weft, and was impregnated with the epoxy resin used in Example 1 to obtain a prepreg sheet. The thus obtained prepregs of inorganic fibers and aramid fibers were laminated and hot pressed to produce a hybrid fiber-reinforced epoxy composite. The fiber content of this composite was 30% by volume of inorganic fibers and 30% by volume of aramid fibers, for a total of 60% by volume.

The resulting composite had a tensile strength of 92 Kg/mm ² , a tensile modulus of 5.0 t/mm ² , a bending strength of 81 Kg/mm ² , a flexural modulus of 6.9 t/mm ² , and an interlaminar shear strength of 10.2 Kg/mm ² , the bending impact value was 258 kg·cm/cm ² . This composite exhibited a beautiful color tone reflecting the bright blue reflected light emitted from the inorganic fibers that make up the hybrid fiber.

Example 7 An 8-ply satin cloth was manufactured using the carbon fiber used in Example 1 for the warp and the inorganic fiber [ ] for the weft, and was impregnated with polyimide resin to obtain a prepreg. The thus obtained prepregs of inorganic fibers and carbon fibers were laminated and hot pressed to produce a hybrid fiber-reinforced polyimide composite. The fiber content of this composite is 15% by volume of inorganic fiber [] and 45% by volume of carbon fiber.
It was 60% by volume.

The obtained composite had a tensile strength of 70 Kg/mm ² , a tensile modulus of 6.5 t/mm ² , a bending strength of 62 Kg/mm ² , a flexural modulus of 6.1 t/mm ² , and an interlaminar shear strength of 9.3 Kg/mm ² , the bending impact value was 263Kg·cm/ ^cm2 . This composite exhibited a beautiful color tone reflecting the bright blue reflected light emitted from the inorganic fibers that make up the hybrid fiber.

Example 8 An 8-ply satin cloth was manufactured using the carbon fiber used in Example 1 for the warp and the inorganic fiber [ ] for the weft, and was impregnated with nylon-66 resin to obtain a prepreg. The thus obtained prepregs of inorganic fibers and carbon fibers were laminated and hot pressed to produce a hybrid fiber-reinforced nylon composite. The fiber content of this composite is 15% by volume of inorganic fibers and 45% by volume of carbon fibers, totaling 60% by volume.
It was in volume %.

The obtained composite has a tensile strength of 118 Kg/mm ² , a tensile modulus of 9.4 t/mm ² , a bending strength of 71 Kg/mm ² , a flexural modulus of 6.8 t/mm ² , and an interlaminar shear strength of 9.9 Kg/mm ² , the bending impact value was 270Kg·cm/ ^cm2 . This composite exhibited a beautiful color tone reflecting the bright blue reflected light emitted from the inorganic fibers that make up the hybrid fiber.

Example 9 On pure aluminum foil (1070) with a thickness of 0.5 mm,
Inorganic fibers [] were arranged in a uniaxial direction, aluminum foil was placed on top of the inorganic fibers, and a composite foil A in which fibers and aluminum foil were composited was produced by hot rolling at a temperature of 670°C. Composite foil B using silicon carbide fibers and aluminum foil was produced in a similar manner.

After stacking a total of 28 sheets of these composite foils A and B alternately and leaving them under vacuum at a temperature of 670℃ for 10 minutes,
An inorganic fiber-reinforced aluminum composite was produced by hot pressing at 600°C. The fiber content of this composite is 15% by volume of inorganic fiber [ ] and silicon carbide fiber, and the natural metallic luster of the aluminum matrix and the blue reflected light generated from the surface of the included inorganic fiber [ ] showed a mild blue color tone.

The tensile strength of the composite is 52Kg/mm ² and the tensile modulus is
It was 7.2t/ ^mm2 .

Claims (1)

[Scope of Claims] 1 A reinforcing material made of a hybrid fiber of an inorganic fiber and at least one type of fiber selected from the group consisting of carbon fiber, glass fiber, boron fiber, aramid fiber, and silicon carbide fiber having a carbon core, In a hybrid fiber-reinforced composite having a plastic or metal matrix, the inorganic fibers are () an amorphous material consisting essentially of Si, M, C and O, or () an amorphous substance consisting essentially of β-SiC, MC, A solid solution of β-SiC and MC and/or each crystalline ultrafine particle with a particle size of 500 Å or less of MC _1-X , and amorphous SiO ₂ and MO ₂
or () a mixed system of the amorphous substance mentioned in () above and the crystalline ultrafine particle aggregate mentioned in () above, made of inorganic fibers containing silicon, titanium or zirconium, carbon and oxygen. an inner layer, () an amorphous material consisting essentially of Si, M and O, () an aggregate consisting of crystalline SiO ₂ and MO ₂ , or () an amorphous substance of () above and () ) mixed system of crystalline polymers (however, in the above formula, M represents Ti or Zr, and x is 0
A number greater than 1 and less than 1. 1. A hybrid fiber-reinforced composite comprising silicon, titanium or zirconium consisting of 1.) and a surface layer consisting of an inorganic material containing oxygen and optionally 5% by weight or less of carbon.