JP2007031186A - Fibrous composite and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fibrous composite having improved strength and toughness and to provide a method of manufacturing the fibrous composite. <P>SOLUTION: The fibrous composite having improved strength and toughness is manufactured by adding a compound containing a metal element to polysilane or heated reaction product thereof and causing a reaction by heating under an inert gas to prepare a metal element-containing organosilicon polymer, preparing a spun fiber from the metal element-containing organosilicon polymer, heating the spun fiber under an oxygen-containing gas to prepare an infusibilized fiber, heating the infusibilized fiber under an inert gas to form a mineralized fiber, mixing a plurality of the mineralized fibers with a plurality of reinforcing fibers or their bundle to make a preliminarily shaped material, charging the preliminarily shaped material into a mold and pressing at a high temperature in a gas such as an inert gas. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fiber bonded body including a deformable fiber and a reinforcing fiber whose columnar cross-sectional shape can be deformed into a polygonal shape, or a manufacturing method thereof.

Up to now, ceramic materials that are hard to break have been developed for the purpose of application to high-temperature structural materials such as gas turbines. In recent years, thermal shock resistance, strength properties at high temperatures, phase stability, and oxidation resistance have been developed. A sintered SiC fiber bonded body that is excellent and improved in brittleness, which is a drawback of ceramic materials, has been reported (see Patent Document 1). This sintered SiC fiber bonded body has a structure in which fibers are packed and bonded almost closely through a boundary layer mainly composed of carbon, and the mineralized fibers constituting this bonded body are in the mold. It is known that a circular cross section is deformed into a polygonal shape by charging and hot pressing.
JP 11-92227 A

  As described above, a sintered SiC fiber bonded body is a material having excellent characteristics. However, in order to improve the reliability of the material and to apply the actual machine, development of a material with further improved strength, toughness, etc. Is required.

  Accordingly, an object of the present invention is to provide a fiber bonded body with improved strength and toughness and a method for producing the same.

  According to the study by the present inventors, the above-mentioned sintered SiC fiber bonded body has a deformed fiber whose cross section is deformed from a circular shape to a polygonal shape. When pulling out from the defective part, it was thought that stress concentrated on the corners of the deformed fiber promoted the destruction of the fiber and restricted the strength development of the sintered SiC fiber bonded body.

  From the above, the present inventors mixed the deformed fiber and the reinforcing fiber having a circular cross-sectional shape in which the cross-sectional shape is difficult to deform, thereby reducing the number of corners of the deformed fiber serving as a stress concentration source. The present invention has been completed by considering that the strength of the fiber bonded body can be increased relatively less than when not mixed.

  That is, the manufacturing method according to the present invention is a method of manufacturing a fiber bonded body including a plurality of deformable fibers whose cross-sectional shape can be deformed into a polygon and a plurality of circular cross-sectional reinforcing fibers or bundles thereof. The polysilane having a molar ratio of carbon atoms to silicon atoms of 1.5 or more or a heated reaction product thereof contains at least one metal element selected from the group consisting of 2A group, 3A group, and 3B group A first step of adding a compound and heating to react in an inert gas to prepare a metal element-containing organosilicon polymer; and melt spinning or dry spinning the metal element-containing organosilicon polymer to produce a spun fiber. A second step of preparing, a third step of preparing the infusible fiber by heating the spun fiber in an oxygen-containing gas at a temperature in the range of 50 to 170 ° C., and inactivating the infusible fiber. Add in gas A fourth step of preparing mineralized fibers by mineralization by processing, and a fifth step of preparing a preform by mixing a plurality of the mineralized fibers and a plurality of the reinforcing fibers or bundles thereof. The preliminary shape is charged into a mold, and the temperature is in the range of 1700 to 2200 ° C. in a vacuum or at least one gas selected from the group consisting of an inert gas, a reducing gas, and a hydrocarbon gas. And a sixth step of applying pressure. The manufacturing method according to the present invention includes, after the third step, a fourth step in which a plurality of the infusible fibers and a plurality of the reinforcing fibers or a bundle thereof are mixed to produce a preliminary shape, After preliminarily shaped material is charged into a mold and heat-treated in an inert gas, the infusible fiber in the preliminary shaped material is mineralized, and then vacuum, or from inert gas, reducing gas, and hydrocarbon gas It is good also as including the 5th process pressurized in the gas which consists of at least 1 sort (s) chosen from the group which consists of 1700-2200 degreeC. The bundle of reinforcing fibers is preferably impregnated in advance with a SiC precursor resin or a ceramic sol.

  Further, the fiber bonded body according to the present invention has a substantially close-packed structure, a plurality of deformed fibers having a cylindrical cross-sectional shape deformed into a polygonal shape, and a plurality of reinforcing fibers having a circular cross-sectional shape or a bundle thereof. And the deformed fiber contains at least one metal selected from the group consisting of 2A group, 3A group, and 3B group, and is mainly composed of a sintered structure of SiC. And a boundary layer mainly composed of carbon is formed on the surface of the deformed fiber.

  In addition, it is preferable that the reinforcing fibers in the preliminary shape are configured to be separated from each other. The reinforcing fiber preferably has a sliding layer on the surface of the fiber. The reinforcing fiber is preferably, for example, one or two or more fibers selected from the group consisting of ceramic fibers, carbon fibers, and high melting point metal fibers. Furthermore, the said pre-shaped thing is what the several said mineralization fiber or infusible fiber, and the said several reinforcement fiber or its bundle are aligned in one direction, or is woven. It is preferable.

  According to the present invention, it is possible to provide a fiber bonded body with improved strength and toughness and a method for manufacturing the same.

Hereinafter, preferred embodiments will be described in detail with reference to the drawings.
In the fiber bonded body according to the present invention, a plurality of deformed fibers and a plurality of reinforcing fibers or a bundle thereof are bonded in a close-packed structure, and the surface of the deformed fibers is mainly composed of carbon. A boundary layer is formed. As described above, by including the reinforcing fiber in the fiber bonded body, it is possible to obtain superior strength and toughness as compared with the conventional sintered SiC fiber bonded body. Further, since the fiber bonded body according to the present invention has a boundary layer mainly composed of carbon formed on the surface of the deformed fiber, it acts as a sliding layer at the time of breakage, and the deformed fiber crosslinks the crack or the fiber bonded body. It is possible to suppress the material from being immediately broken by being pulled out from.

  The deformed fiber may be any inorganic fiber that contains a metal and is mainly composed of a sintered structure of SiC and has a cross-sectional shape that is deformed from a circle to a polygon. Preferred are those containing wt% Si, 30 to 45 wt% C, and 0.05 to 4.0 wt% (preferably 0.1 to 2.0 wt%) metal. . Examples of the metal include 2A group (for example, Be, Mg, Ca, Sr, Ba, Ra, etc.), 3A group (for example, Sc, Y, La, Ce, etc.), and 3B group (for example, B, Al, Ga, etc.). Is not particularly limited as long as it is at least one metal selected from the group consisting of In, Tl, etc.), but is known as a sintering aid for SiC. Be, Mg, Y, Ce, B, Al or the like in which a chelate compound or alkoxide compound capable of reacting is present is preferable.

Further, the reinforcing fiber is not particularly limited as long as it is a fiber having a circular cross-sectional shape that is difficult to deform even when pressurized in a mold at a high temperature. For example, carbon fiber, ceramic fiber (for example, Si -C, Si-Ti-CO, Si-Zr-CO, Si-Al-CO, Si-CO, Si-COB, Si-CN and other carbide ceramic fibers, Al ₂ O _{3 and} other oxide ceramic fibers Nitride ceramic fibers such as Si3N4), refractory metal fibers (for example, fibers made of Mo, W, or the like) can be used.

  The reinforcing fiber may have a sliding layer formed of carbon, boron nitride or the like on the surface, or a sliding layer formed of a layer of a material such as carbon or boron nitride and silicon carbide having excellent oxidation resistance. preferable. By forming a sliding layer on the reinforcing fiber in this way, at the time of breaking, the reinforcing fiber promotes the cross-linking of cracks or pulls out from the fiber bonded body, and in the case of a fiber bonded body made of the deformed fiber. In comparison, the material can be further prevented from breaking immediately. The sliding layer may be formed on the surface of the reinforcing fiber by a chemical vapor deposition (CVD) method using a sliding layer forming material such as carbon or boron nitride, but the sliding layer forming material is dispersed in a solvent. It is good also as forming a slipping layer forming substance adhering to the surface of a reinforced fiber by immersing a reinforced fiber in the made slurry.

  In the present invention, in order to prevent contact between the reinforcing fibers, a fiber bonded body configured such that the reinforcing fibers are separated from each other is preferable. When a bundle of reinforcing fibers is used instead of the reinforcing fibers, the reinforcing fibers are preferably separated from each other so that the reinforcing fibers in the bundle do not contact each other. Thus, it becomes possible to prevent generation | occurrence | production of the damage with respect to the surface of a reinforced fiber by preventing the contact between reinforced fibers. In addition, a bundle of reinforcing fibers configured to be separated from each other so that the reinforcing fibers do not contact each other is impregnated with a known SiC precursor resin solution or ceramic sol such as polyvinylsilane, polymethylsilane, polydimethylsilane, etc. Then, it can be produced by heat treatment under pressure.

  Further, in the present invention, many of the reinforcing fibers 2 and the deformed fibers 1 are included within a range where the reinforcing fibers 2 do not contact each other as shown in FIG. The fiber combination 10 including the bundle 10 of reinforcing fibers and the bundle 3 of reinforcing fibers configured so that the reinforcing fibers 2 are not in contact with each other and the deformed fibers 1 as shown in FIG.

  In the above description, a fiber bonded body in which a plurality of deformed fibers and a plurality of reinforcing fibers or bundles thereof are aligned in one direction has been described. However, a plurality of deformed fibers and a plurality of reinforcing fibers or bundles thereof are many. A fiber bonded body woven in a dimension may be used.

  Hereinafter, the manufacturing method of the coupling fiber body concerning the present invention is explained. The above bonded fiber body is selected from the group consisting of 2A group, 3A group, and 3B group, for example, polysilane having a molar ratio of carbon atom to silicon atom of 1.5 or more or a heated reaction product thereof. And a metal element-containing organosilicon polymer is prepared by heating and reacting in an inert gas, and the metal element-containing organosilicon polymer is melt-spun or dry-spun. A spun fiber is prepared by heating the spun fiber in an oxygen-containing gas at a temperature in the range of 50 to 170 ° C. to prepare an infusible fiber, and the infusible fiber is previously inorganic in an inert gas. To prepare a mineralized fiber, and a plurality of the mineralized fiber and a plurality of the reinforcing fibers are mixed to prepare a preliminary shape, and the preliminary shape is charged into a mold, and vacuum or an inert gas is prepared. ,reduction Scan, and in a gas consisting of at least one selected from the group consisting of hydrocarbon gas, it can be prepared by pressurizing at a temperature in the range of 1,700 to 2200 ° C.. Also, after preparing a preliminary shape by mixing a plurality of the infusible fibers and a plurality of the reinforcing fibers or bundles thereof, the preliminary shape is charged into a mold, and vacuum, or an inert gas, a reducing gas , And at least one selected from the group consisting of hydrocarbon gas, and can also be produced by pressurizing at a temperature in the range of 1700 to 2200 ° C. as it is.

  Here, examples of the polysilane used in the preparation of the metal element-containing organosilicon polymer include a chain or cyclic polymer having a number average molecular weight of 300 to 1,000. The side chain of silicon of the polysilane may be, for example, a hydrogen atom, a lower alkyl group, an aryl group, a phenyl group, a silyl group, etc., but in order to form a boundary carbon layer on the surface of the deformed fiber, Any of the polysilanes needs to have a molar ratio of carbon atoms to silicon atoms of 1.5 or more. The polysilane may be an organosilicon polymer partially containing a carbosilane bond in addition to the polysilane bond unit obtained by heating the chain or cyclic polysilane.

  The compound containing a metal element used in the preparation of the metal element-containing organosilicon polymer contains at least one metal element selected from the group consisting of the above-mentioned 2A group, 3A group, and 3B group Any metal element can be bonded to Si directly or via other elements by reacting with Si-H bonds in the organosilicon polymer produced by polysilane or its heated reaction product. For example, an alkoxide having the above metal element, an acetylacetoxide compound, a carbonyl compound, a cyclopentadienyl compound, or the like can be used. More specifically, beryllium acetylacetonate, magnesium acetylacetonate, Yttrium acetylacetonate, cerium acetylacetonate, boric acid Tokishido, and aluminum acetylacetonate.

  The metal element-containing organosilicon polymer is prepared by adding a compound containing the above metal element to the above polysilane or a heated reaction product thereof and at a temperature in the range of 250 to 350 ° C. in an inert gas. The reaction can be carried out by heating for 1 to 10 hours. The metal-containing organosilicon polymer obtained as described above is a crosslinked polymer having a structure in which at least a part of silicon atoms of polysilane are bonded with or without metal atoms and oxygen atoms. .

  As described above, the spinning fiber may be prepared by melt spinning the metal element-containing organosilicon polymer, or the metal element-containing organosilicon polymer may be prepared using an organic solvent (for example, benzene, toluene, Alternatively, it may be carried out by dry spinning after dissolving in xylene or the like.

  The process for preparing the infusible fiber from the spun fiber is to form a crosslinking point by oxygen atoms between the polymers constituting the spun fiber, and the infusible fiber does not melt in the mineralization process described later, and adjacent fibers are This is done to prevent fusion. Examples of the oxygen-containing gas used in this treatment include air, oxygen, ozone, and the like.

The mineralization treatment of the infusible fiber is performed continuously or batchwise by heating the infusible fiber in an inert gas such as argon, nitrogen or air at a temperature in the range of 1000 to 1700 ° C. be able to. Here, the infusible fiber to be mineralized is preferably one containing 8 to 16% by weight of oxygen. By containing oxygen in the infusible fiber as described above, surplus carbon existing in the mineralized fiber can be released as CO or CO ₂ gas. When the oxygen content is less than 8% by weight, excess carbon in the mineralized fiber remains more than necessary, and segregates around the SiC crystal in the temperature rising process to stabilize the SiC. If the amount is more than 16% by weight, surplus carbon in the mineralized fiber is completely desorbed and a boundary carbon layer between the fibers is not generated, which is considered to adversely affect the mechanical properties of the material. It is done.

  The infusible fiber is preferably heat-treated at 150 to 800 ° C. in an inert gas in advance before the mineralization treatment. As a result, while preventing oxygen uptake into the fiber, the crosslinking reaction of the polymer constituting the fiber is further advanced, and the excellent elongation of the infusible fiber from the precursor metal polymer is maintained, and the strength is further increased. Can be improved. Accordingly, it is possible to perform the mineralization treatment efficiently and stably.

  The preliminary shaped material is a mixture of reinforcing fibers or bundles thereof and mineralized fibers or infusible fibers so that the bonded fiber body according to the present invention can be obtained.

  As described above, the fiber bonded body according to the present invention can be manufactured. In this embodiment, the slip layer is formed on the surface of the reinforcing fiber by a chemical vapor deposition method using the slip layer forming substance, but it is generated from the reinforcing fiber in the heating reaction of the preliminary shape. It is good also as forming a slipping layer on the said fiber surface with the done carbon.

It is a figure which shows the structure of the fiber coupling body containing the reinforced fiber 2 and the deformation | transformation fiber 1 demonstrated as an example of this Embodiment. It is a figure which shows the structure of the fiber coupling body containing the bundle 3 of the reinforced fiber and the deformation | transformation fiber 1 demonstrated as an example of this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deformation fiber 2 Reinforcement fiber 3 Reinforcement fiber bundle 10 Fiber conjugate

Claims (13)

A method of manufacturing a fiber bonded body including a plurality of deformable fibers whose cross-sectional shape can be deformed into polygons, and a plurality of circular cross-sectional reinforcing fibers or bundles thereof
A compound containing at least one metal element selected from the group consisting of 2A group, 3A group, and 3B group in polysilane having a molar ratio of carbon atom to silicon atom of 1.5 or more or a heated reaction product thereof A first step of preparing a metal element-containing organosilicon polymer by heating and reacting in an inert gas;
A second step of preparing a spun fiber by melt spinning or dry spinning the metal element-containing organosilicon polymer;
A third step of preparing the infusible fiber by heating the spun fiber in an oxygen-containing gas at a temperature in the range of 50 to 170 ° C .;
A fourth step in which the infusibilized fiber is mineralized by heat treatment in an inert gas to produce the mineralized fiber;
A fifth step of preparing a preform by mixing a plurality of the mineralized fibers and a plurality of the reinforcing fibers or bundles thereof;
The preliminary shape is charged into a mold, and at a temperature in the range of 1700 to 2200 ° C. in a vacuum or at least one gas selected from the group consisting of an inert gas, a reducing gas, and a hydrocarbon gas. A sixth step of applying pressure;
The manufacturing method of the fiber coupling body characterized by including. A method of manufacturing a fiber bonded body including a plurality of deformable fibers whose cross-sectional shape can be deformed into polygons, and a plurality of circular cross-sectional reinforcing fibers or bundles thereof
A compound containing at least one metal element selected from the group consisting of 2A group, 3A group, and 3B group in polysilane having a molar ratio of carbon atom to silicon atom of 1.5 or more or a heated reaction product thereof A first step of preparing a metal element-containing organosilicon polymer by heating and reacting in an inert gas;
A second step of preparing a spun fiber by melt spinning or dry spinning the metal element-containing organosilicon polymer;
A third step of preparing the infusible fiber by heating the spun fiber in an oxygen-containing gas at a temperature in the range of 50 to 170 ° C .;
A fourth step of preparing a preliminary shape by mixing a plurality of the infusible fibers and a plurality of the reinforcing fibers or bundles thereof;
The preform is charged into a mold and heat treated in an inert gas to mineralize the infusible fiber in the preform, and then vacuum, or an inert gas, a reducing gas, and a hydrocarbon gas A fifth step of pressurizing at a temperature in the range of 1700 to 2200 ° C. in a gas consisting of at least one selected from the group consisting of:
The manufacturing method of the fiber coupling body characterized by including.   The method for producing a fiber bonded body according to claim 1 or 2, wherein the reinforcing fibers in the preliminary shape are configured to be separated from each other.   3. The method for producing a fiber bonded body according to claim 1, wherein the bundle of reinforcing fibers is impregnated in advance with a SiC precursor resin or a ceramic sol.   The said reinforcing fiber has a sliding layer on the surface of the said fiber, The manufacturing method of the fiber conjugate | bonding body in any one of Claims 1-3 characterized by the above-mentioned.   6. The fiber bond according to claim 1, wherein the reinforcing fiber is one or two or more fibers selected from the group consisting of ceramic fibers, carbon fibers, and high melting point metal fibers. Body manufacturing method.   The preliminary-shaped object is characterized in that a plurality of the mineralized fibers or infusibilized fibers and a plurality of the reinforcing fibers or bundles thereof are aligned or woven in one direction. The manufacturing method of the fiber conjugate | bonded_body in any one of Claims 1-6. It is a fiber bonded body in which a plurality of deformed fibers whose cylindrical cross-sectional shape is deformed into a polygonal shape and a plurality of circular cross-sectional reinforcing fibers or bundles thereof are bonded in a substantially close-packed structure,
The deformed fiber contains at least one metal selected from the group consisting of Group 2A, Group 3A, and Group 3B, and is an inorganic fiber mainly composed of a sintered structure of SiC.
A fiber bonded body, wherein a boundary layer mainly composed of carbon is formed on a surface of the deformed fiber.   The fiber bonded body according to claim 8, wherein the reinforcing fibers are configured to be separated from each other.   9. The fiber bonded body according to claim 8, wherein an inorganic substance obtained by mineralizing the SiC precursor resin or the ceramic sol is present between the individual reinforcing fibers in the bundle of reinforcing fibers.   The fiber reinforced product according to claim 8 or 9, wherein the reinforcing fiber has a sliding layer on a surface of the fiber.   The fiber-bonding according to any one of claims 8 to 11, wherein the reinforcing fiber is one or two or more fibers selected from the group consisting of ceramic fibers, carbon fibers, and high melting point metal fibers. Body manufacturing method. The plurality of deformed fibers and the plurality of reinforcing fibers or bundles thereof are aligned or woven in one direction, according to any one of claims 8 to 12. Fiber bonded body.

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