JP2018030753A - Long fiber-reinforced silicon carbide member and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long fiber-reinforced silicon carbide member that can improve reliability such as mechanical properties, and the like.SOLUTION: A long fiber-reinforced silicon carbide member 1 according to an embodiment has a cylindrical shape and includes a composite material layer 11 and a graphite surface layer 21. In the composite material layer, a matrix of silicon carbide forms a composite with a long fiber of silicon carbide. The graphite surface layer is formed on a face of the composite material layer.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to a long fiber reinforced silicon carbide member and a method for manufacturing the same.

  In general, a silicon carbide member, which is a ceramic material, has a small decrease in strength in a high-temperature environment. In addition, the silicon carbide member has higher hardness than conventional metal members, and is excellent in characteristics such as wear resistance, heat resistance, corrosion resistance, and light weight. For this reason, silicon carbide members are used in a wide range of fields. For example, silicon carbide members are used as materials for heavy electrical equipment parts, aircraft parts, automobile parts, electronic equipment, precision machine parts, and semiconductor devices.

  However, a silicon carbide monolithic member that is a silicon carbide member is weaker in tensile stress than compressive stress, and brittle fracture may occur when tensile stress is applied. For this reason, in order to increase toughness and increase fracture energy than silicon carbide monolithic members, long fiber reinforced silicon carbide members in which silicon carbide long fibers (continuous fibers) are combined in a silicon carbide matrix are silicon carbide members. Has been developed as.

  When producing a long fiber reinforced silicon carbide member, first, for example, after forming a fiber bundle (yarn) by bundling 500 to 3000 long silicon carbide fibers having a diameter of about 10 μm, the fiber bundle Is used to form a preform (fiber preform) having a predetermined shape. In addition to being formed by arranging the fiber bundles in a two-dimensional direction or a three-dimensional direction, the preform is formed by weaving the fiber bundles.

  Next, a long fiber reinforced silicon carbide member is completed by forming a matrix inside the preform. Formation of a matrix is performed by the chemical vapor infiltration (CVI; Chemical Vapor Infiltration) method, for example. In addition, the formation of the matrix is performed by performing reactive sintering after filling the powder into the preform by a casting method.

U.S. Pat. US Patent Application Publication No. 2011/0268243 JP2016-24062A Japanese Patent No. 4106086

  As described above, in the silicon carbide member, the long fiber reinforced silicon carbide member has higher toughness and increased fracture energy than the silicon carbide monolithic member, and apparently does not easily cause brittle fracture. However, conventionally, the long fiber reinforced silicon carbide member has an initial fracture strength in a tensile test lower than that of the silicon carbide monolithic member. Further, the long fiber reinforced silicon carbide member may not have sufficient values for maximum strength and fracture resistance.

  In addition, the silicon carbide member may be corroded by oxidation in high-pressure water. As a result, thinning of the silicon carbide member may occur, and the mechanical properties of the silicon carbide member may deteriorate.

  Therefore, the problem to be solved by the present invention is to provide a long fiber reinforced silicon carbide member capable of improving reliability such as mechanical properties and a method for producing the same.

  The long fiber reinforced silicon carbide member of the embodiment has a cylindrical shape and has a composite material layer and a graphite surface layer. In the composite material layer, silicon carbide long fibers are combined with a silicon carbide matrix. The graphite surface layer is formed on the surface of the composite material layer.

  ADVANTAGE OF THE INVENTION According to this invention, the long fiber reinforced silicon carbide member which can improve reliability, such as a mechanical characteristic, and its manufacturing method can be provided.

FIG. 1 is a perspective view schematically showing a long fiber reinforced silicon carbide member according to the first embodiment. FIG. 2 is an enlarged cross-sectional view of a part of the long fiber reinforced silicon carbide member according to the first embodiment. FIG. 3 is a perspective view schematically showing a long fiber reinforced silicon carbide member according to a modification of the first embodiment. FIG. 4 is a cross-sectional view schematically showing a long fiber reinforced silicon carbide member according to a modification of the first embodiment. FIG. 5 is a cross-sectional view schematically showing a part of the long fiber reinforced silicon carbide member according to the second embodiment. FIG. 6 is a cross-sectional view schematically showing a long fiber reinforced silicon carbide member according to a modification of the second embodiment. FIG. 7 is a cross-sectional view schematically showing a part of the long fiber reinforced silicon carbide member according to the third embodiment. FIG. 8 is a cross-sectional view schematically showing a part of a long fiber reinforced silicon carbide member according to a modification of the third embodiment.

<First Embodiment>
FIG. 1 is a perspective view schematically showing a long fiber reinforced silicon carbide member according to the first embodiment.

  As shown in FIG. 1, the long fiber reinforced silicon carbide member 1 of the present embodiment is, for example, a cylindrical tubular body having a structure in which long fibers are continuously arranged without being cut.

  FIG. 2 is an enlarged cross-sectional view of a part of the long fiber reinforced silicon carbide member according to the first embodiment. In FIG. 2, regarding the long fiber reinforced silicon carbide member 1, a cross section in which the axial direction is orthogonal is shown.

  As shown in FIG. 2, the long fiber reinforced silicon carbide member 1 has a composite material layer 11 and a graphite surface layer 21.

  The composite material layer 11 is composed of silicon carbide long fibers in a silicon carbide matrix.

  The graphite surface layer 21 is a graphite outer surface layer 211 and a graphite inner surface layer 212. The graphite outer surface layer 211 is formed on the outer peripheral surface of the composite material layer 11. The graphite inner surface layer 212 is formed on the inner peripheral surface of the composite material layer 11.

  The graphite surface layer 21 preferably has a thickness of 100 μm or more and less than 200 μm. When the thickness of the graphite surface layer 21 is thinner than the above range, the surface of the composite material layer 11 may not be sufficiently covered. Further, when the thickness of the graphite surface layer 21 is larger than the above range, the thermal expansion coefficient of the graphite surface layer 21 and the thermal expansion coefficient of the composite material layer 11 are different. The layer 21 is easily peeled from the surface of the composite material layer 11.

  In this embodiment, each process for manufacturing the long fiber reinforced silicon carbide member 1 will be described.

  When manufacturing the long fiber reinforced silicon carbide member 1, the composite material layer 11 is first prepared. In this step, for example, after forming a fiber bundle (yarn) by bundling a plurality of long fibers of silicon carbide, a preform (fiber preform) is formed into a cylindrical shape using the fiber bundle. Then, a matrix is formed on the preform. The matrix is formed by, for example, chemical vapor infiltration. In this manner, a composite material layer 11 in which silicon carbide long fibers are combined with a silicon carbide matrix is completed.

  Next, a graphite surface layer 21 is formed on the surface of the prepared composite material layer 11. In this step, for example, the graphite surface layer 21 is formed by decomposing the surface of the composite material layer 11 by heating. Here, for example, the graphite surface layer 21 is formed by thermally decomposing silicon carbide existing on the surface of the composite material layer 11 to generate graphite in a reduced pressure atmosphere. Specifically, the surface decomposition of the composite material layer 11 is performed in a vacuum atmosphere in which the temperature is 1300 to 1500 ° C. and the pressure is 0.1 Pa or less. By this method, the graphite surface layer 21 can be densely formed.

  The surface decomposition of the composite material layer 11 may be performed in an atmosphere having a temperature of 1300 to 1500 ° C. and containing a mixed gas of carbon monoxide and carbon dioxide. By this method, the graphite surface layer 21 can be densely formed as in the above method.

  Further, the graphite surface layer 21 may be formed by vapor-depositing graphite on the surface of the composite material layer 11 by a thermal chemical vapor deposition method (thermal CVD method). Also by this method, the graphite surface layer 21 can be densely formed as in the above method. Here, after the silicon carbide matrix is formed, the graphite surface layer 21 can be continuously formed in the same reactor by changing the raw material gas and the process conditions.

  In addition, the graphite surface layer 21 may be formed by combining the above methods. Specifically, after forming a graphite layer (not shown) by surface decomposition of the composite material layer 11, another graphite layer (not shown) is further laminated by a thermal chemical vapor deposition method, thereby obtaining a graphite surface layer. 21 may be formed. Thereby, the graphite surface layer 21 can be formed more densely, and the adhesion between the composite material layer 11 and the graphite surface layer 21 can be improved.

  As described above, in the long fiber reinforced silicon carbide member 1 of this embodiment, the dense graphite surface layer 21 is formed on the surface of the composite material layer 11. For this reason, in this embodiment, reliability, such as a mechanical characteristic, can be improved about the long fiber reinforced silicon carbide member 1. In particular, this embodiment can suppress the occurrence of corrosion due to oxidation in high-pressure water. As a result, it is possible to suppress the occurrence of thinning in the long fiber reinforced silicon carbide member 1 and improve the mechanical characteristics.

  Therefore, the long fiber reinforced silicon carbide member 1 of the present embodiment includes a reactor structural material (channel box, fuel rod, control rod structural material, etc.), seal material (submersible pump, etc.), spacecraft member, artificial satellite member. As such materials, it can be suitably used.

  3 and 4 are views schematically showing a long fiber reinforced silicon carbide member according to a modification of the first embodiment. 3 is a perspective view similar to FIG. 1, and FIG. 4 is a cross-sectional view similar to FIG. In FIGS. 3 and 4, portions overlapping those in FIGS. 1 and 2 are denoted by the same reference numerals as appropriate, and description thereof is omitted.

  As shown in FIGS. 3 and 4, the long fiber reinforced silicon carbide member 1 may be a rectangular tube-shaped tubular body.

Second Embodiment
FIG. 5 is a cross-sectional view schematically showing a part of the long fiber reinforced silicon carbide member according to the second embodiment. In FIG. 5, as in FIG. 2, the long fiber reinforced silicon carbide member 1 is shown with respect to a cross section in which the axial direction is orthogonal.

  As shown in FIG. 5, in this embodiment, the long fiber reinforced silicon carbide member 1 further includes a graphite intermediate layer 31 and a silicon carbide monolithic layer 41, unlike the case of the first embodiment. Except for this point and points related thereto, the present embodiment is the same as the case of the first embodiment. For this reason, about the overlapping part, the same code | symbol is attached | subjected suitably and the description is abbreviate | omitted.

The graphite intermediate layer 31 is formed on the outer peripheral surface of the composite material layer 11.
The graphite intermediate layer 31 preferably has a thickness of 10 μm or more and less than 100 μm.
When the thickness of the graphite intermediate layer 31 is thinner than the above range, the fracture resistance may decrease. Moreover, when the thickness of the graphite intermediate layer 31 is thicker than the above range, the fracture strength may decrease.

  Silicon carbide monolithic layer 41 is formed on the outer peripheral surface of graphite intermediate layer 31. That is, the silicon carbide monolithic layer 41 is formed on the outer peripheral surface of the composite material layer 11 via the graphite intermediate layer 31. A graphite outer surface layer 211 is formed on the outer peripheral surface of the silicon carbide monolithic layer 41. The thickness of the silicon carbide monolithic layer 41 is selected to be a thickness that can suppress “crack propagation” from the monolithic layer, and is preferably equal to or less than that of the composite material layer 11.

  In this embodiment, each process for manufacturing the long fiber reinforced silicon carbide member 1 will be described.

  When the long fiber reinforced silicon carbide member 1 is manufactured, the composite material layer 11 is first prepared in the same manner as in the first embodiment.

  Next, the graphite intermediate layer 31 is formed on the surface of the prepared composite material layer 11. In this step, for example, the graphite intermediate layer 31 can be formed by a method similar to the method of forming the graphite surface layer 21 in the first embodiment. That is, for example, the graphite intermediate layer 31 can be formed by decomposing the surface of the composite material layer 11 by heating. In addition, the graphite intermediate layer 31 may be formed by thermal chemical vapor deposition.

  Next, a silicon carbide monolithic layer 41 is formed on the surface of the graphite intermediate layer 31. In this step, for example, the silicon carbide monolithic layer 41 is formed by vapor-depositing silicon carbide alone by a thermal chemical vapor deposition method.

  Next, the graphite surface layer 21 is formed on the surface of the silicon carbide monolithic layer 41. In this step, the graphite surface layer 21 can be formed by the same method as in the first embodiment. That is, for example, the graphite surface layer 21 can be formed by decomposing the surface of the silicon carbide monolithic layer 41 by heating. In addition, the graphite surface layer 21 may be formed by a thermal chemical vapor deposition method.

  As described above, the long fiber reinforced silicon carbide member 1 of the present embodiment includes the graphite intermediate layer 31 and the silicon carbide monolithic layer 41 between the composite material layer 11 and the graphite surface layer 21 from the composite material layer 11 side. Are sequentially provided. For this reason, in this embodiment, reliability, such as a mechanical characteristic, can be further improved about the long fiber reinforced silicon carbide member 1. Specifically, when a crack is generated on the surface of the long fiber reinforced silicon carbide member 1, the crack proceeds in the silicon carbide monolithic layer 41, but the progress of the crack can be stopped by the graphite intermediate layer 31. As a result, in this embodiment, in addition to the operation and effect of the first embodiment, the initial fracture strength of the long fiber reinforced silicon carbide member 1 can be increased.

  FIG. 6 is a diagram schematically showing a long fiber reinforced silicon carbide member according to a modification of the second embodiment. FIG. 6 is a cross-sectional view similar to FIG. In FIG. 6, the same parts as those in FIG. 5 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 6, the long fiber reinforced silicon carbide member 1 may be a rectangular tube-shaped tubular body.

<Third Embodiment>
FIG. 7 is a cross-sectional view schematically showing a part of the long fiber reinforced silicon carbide member according to the third embodiment.

  As shown in FIG. 7, the long fiber reinforced silicon carbide member 1 of this embodiment is provided with a carbide surface layer 51 instead of the graphite surface layer 21 of the first embodiment. Except for this point and points related thereto, the present embodiment is the same as the case of the first embodiment. For this reason, about the overlapping part, the same code | symbol is attached | subjected suitably and the description is abbreviate | omitted.

  The carbide surface layer 51 is a carbide outer surface layer 511 and a carbide inner surface layer 512. The carbide outer surface layer 511 is formed on the outer peripheral surface of the composite material layer 11. The carbide inner surface layer 512 is formed on the inner peripheral surface of the composite material layer 11.

  Carbide surface layer 51 is formed such that the composition changes in an inclined manner from silicon carbide to carbides other than silicon carbide as it leaves the surface of composite material layer 11. Here, in the carbide surface layer 51, the composition on the surface side of the composite material layer 11 is all silicon carbide, and the composition on the side farthest from the surface of the composite material layer 11 is composed of carbides other than silicon carbide. It is formed to become. In the carbide surface layer 51, the carbide other than silicon carbide is at least one selected from titanium carbide, zirconium carbide, hafnium carbide, niobium carbide, and tantalum carbide.

  Carbide surface layer 51 preferably has a thickness of 200 nm or more and less than 200 μm. When the thickness of the carbide surface layer 51 is thinner than the above range, the surface of the composite material layer 11 may not be sufficiently covered. Further, when the thickness of the carbide surface layer 51 is thicker than the above range, the thermal expansion coefficient of the carbide surface layer 51 and the thermal expansion coefficient of the composite material layer 11 are different. The layer 51 is easily peeled from the surface of the composite material layer 11.

  In this embodiment, each process for manufacturing the long fiber reinforced silicon carbide member 1 will be described.

  When the long fiber reinforced silicon carbide member 1 is manufactured, the composite material layer 11 is first prepared in the same manner as in the first embodiment.

  Next, a carbide surface layer 51 is formed on the surface of the prepared composite material layer 11. In this step, the carbide surface layer 51 is formed, for example, by depositing carbide on the surface of the composite material layer 11 by thermal chemical vapor deposition (thermal CVD method). Here, the carbide surface layer 51 is formed by adjusting the ratio of the raw material gas so that the composition of the carbide surface layer 51 changes in inclination from silicon carbide to a carbide other than silicon carbide.

  As described above, in the long fiber reinforced silicon carbide member 1 of the present embodiment, the dense carbide surface layer 51 is formed on the surface of the composite material layer 11. The carbide surface layer 51 is a so-called functionally graded film, and the composition changes in an inclined manner from silicon carbide to a carbide other than silicon carbide as it leaves the surface of the composite material layer 11. When the carbide surface layer 51 is not a functionally graded film but formed of a carbide other than silicon carbide (titanium carbide, zirconium carbide, hafnium carbide, niobium carbide, and tantalum carbide), it is caused by a difference in thermal expansion coefficient. Therefore, the carbide surface layer 51 is easily peeled off. However, since the carbide surface layer 51 of this embodiment is a functionally graded film whose composition on the surface side of the composite material layer 11 is silicon carbide as described above, the carbide surface layer 51 is unlikely to peel off. As a result, in this embodiment, the mechanical characteristics of the long fiber reinforced silicon carbide member 1 can be improved.

  FIG. 8 is a diagram schematically showing a long fiber reinforced silicon carbide member according to a modification of the third embodiment. FIG. 8 is a cross-sectional view similar to FIG. 8 that are the same as those in FIG. 5 and FIG.

  As shown in FIG. 8, in this modification, the long fiber reinforced silicon carbide member 1 is replaced with the graphite surface layer 21 of the second embodiment, as in the case of the third embodiment, and the carbide surface layer 51. Is provided.

  For this reason, in this modification, the effect | action and effect of above-described 3rd Embodiment can be show | played with the effect | action and effect of 2nd Embodiment.

  An example of the long fiber reinforced silicon carbide member 1 will be described.

[Example 1]
First, a preformed body (preform) was prepared. In this step, first, carbon having a thickness of about 1 μm was formed by CVD on the surface of a silicon carbide long fiber (trade name: Hynicalon S, manufactured by Nippon Carbon Co., Ltd.) having a diameter of 12 μm. And the cylindrical preform was produced by the filament winding method using the fiber bundle (yarn) which bundled 500 the long fibers.

  Next, a matrix was formed on the preform. In this step, the matrix was formed by chemical vapor infiltration. Specifically, after the preform is set inside the carbon mold in the chemical vapor reactor, the raw material gas (under the conditions that the temperature is 1300 to 1400 ° C. and the pressure is 4 to 100 kPa) (Silicon tetrachloride gas, propane gas, hydrogen gas) were introduced into the reactor. As a result, a matrix mainly composed of silicon carbide was formed on the preform, and the composite material layer 11 was prepared.

  Next, a graphite surface layer 21 was formed on the surface of the prepared composite material layer 11. In this step, the graphite surface layer 21 was formed by decomposing the surface of the composite material layer 11 by heating in an atmosphere containing a mixed gas of carbon monoxide and carbon dioxide. Specifically, the graphite surface layer 21 having a thickness of 200 nm was formed under the conditions where the temperature was 1400 to 1500 ° C.

  As described above, the long fiber reinforced silicon carbide member 1 of [Example 1] (corresponding to the first embodiment) was produced.

[Example 2]
First, a preform (not shown) was prepared. In this step, first, carbon having a thickness of about 0.5 μm was formed by CVD on the surface of long silicon carbide fibers (trade name: Tyranno SA, manufactured by Ube Industries) having a diameter of 10 μm. And the square tube-shaped preform was produced by the filament winding method using the fiber bundle (yarn) which bundled 800 the long fibers.

  Next, a matrix was formed on the preform. In this step, the matrix was formed into a preform by the same method as in Example 1, and the composite material layer 11 was prepared.

  Next, a graphite intermediate layer 31 was formed on the surface of the prepared composite material layer 11. In this step, the graphite intermediate layer 31 was formed by thermal chemical vapor deposition. Specifically, by introducing a raw material gas (methane gas, hydrogen gas) into the reactor under a condition where the temperature is 1000 to 1100 ° C. and the pressure is 4 to 100 kPa, the thickness is about 100 μm. The graphite intermediate layer 31 was formed.

  Next, a silicon carbide monolithic layer 41 was formed on the surface of the graphite intermediate layer 31. In this step, the silicon carbide monolithic layer 41 was formed by depositing silicon carbide alone by a thermal chemical vapor deposition method. Specifically, the raw material gas (silicon tetrachloride gas, propane gas, hydrogen gas) is introduced into the reactor under the conditions that the temperature is 1300 to 1400 ° C. and the pressure is 4 to 100 kPa. Thus, the silicon carbide monolithic layer 41 was formed.

  Next, a carbide surface layer 51 was formed on the surface of the silicon carbide monolithic layer 41. In this step, the carbide surface layer 51 was formed by depositing carbide on the surface of the silicon carbide monolithic layer 41 by thermal chemical vapor deposition. Specifically, the raw material gas (silicon tetrachloride gas, titanium tetrachloride gas, propane gas, hydrogen gas) is supplied to the reactor under the conditions that the temperature is 1300 to 1400 ° C. and the pressure is 4 to 100 kPa. By introducing into the inside, a carbide surface layer 51 having a thickness of about 100 μm was formed. Here, the carbide surface layer 51 was formed by adjusting the ratio of the raw material gas so that the composition of the carbide surface layer 51 changed from silicon carbide to titanium carbide.

  As described above, long fiber reinforced silicon carbide member 1 of [Example 2] (corresponding to a modification of the third embodiment) was produced.

[Comparative Example 1]
The long fiber reinforced silicon carbide member of [Example 1] before being formed with the graphite surface layer 21 was prepared as the long fiber reinforced silicon carbide member of [Comparative Example 1].

[Comparative Example 2]
The long fiber reinforced silicon carbide member of [Example 2] before the silicon carbide monolithic layer 41 was formed was prepared as the long fiber reinforced silicon carbide member of [Comparative Example 2].

[Test results]
With respect to the samples of each of the above examples and comparative examples, an immersion dissolution test (fine ceramic immersion immersion test method; JIS R 1647) and a thermal shock test (fine ceramic thermal shock test method: JIS R 1648) are performed. It was. In the immersion dissolution test, the sample is immersed in test water (ion exchange water, temperature ... 300 ° C, pressure ... saturated vapor pressure) for a predetermined exposure time (200 hours or 500 hours), and a part of the sample is eluted. It was. And the change in the mass of the sample before and after the immersion dissolution test was measured as corrosion weight loss. The thermal shock test was carried out by a submerged quenching method of a test piece drop type. Specifically, after dropping a sample in a high temperature state (1000 ° C. or 1300 ° C.) into water to make it into a low temperature state (room temperature ... 20 ± 3 ° C.), it was observed whether or not the sample was broken (with breakage) … ×, no break… ○). The test results are shown in Table 1.

  As can be seen from Table 1, the long fiber reinforced silicon carbide members of the examples have zero corrosion weight loss and excellent water resistance, and break in a thermal shock test dropped from 1000 ° C. or 1300 ° C. into water. Without having high fracture strength and high fracture resistance.

<Others>
Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Long fiber reinforced silicon carbide member, 11 ... Composite material layer, 21 ... Graphite surface layer, 31 ... Graphite intermediate layer, 41 ... Silicon carbide monolithic layer, 51 ... Carbide surface layer, 211 ... Graphite outer surface layer, 212 ... Graphite inner surface Layers, 511... Carbide outer layer, 512. Carbide inner layer.

Claims (15)

A cylindrical long fiber reinforced silicon carbide member,
A composite material layer in which silicon carbide long fibers are combined in a silicon carbide matrix;
A graphite surface layer formed on the surface of the composite material layer,
Long fiber reinforced silicon carbide member. A cylindrical long fiber reinforced silicon carbide member,
A composite material layer in which silicon carbide long fibers are combined in a silicon carbide matrix;
A graphite intermediate layer formed on the surface of the composite material layer;
A silicon carbide monolithic layer formed on the surface of the graphite interlayer;
A graphite surface layer formed on the surface of the silicon carbide monolithic layer,
Long fiber reinforced silicon carbide member. A cylindrical long fiber reinforced silicon carbide member,
A composite material layer in which silicon carbide long fibers are combined in a silicon carbide matrix;
A carbide surface layer formed on the surface of the composite material layer,
The carbide surface layer is formed such that the composition changes in an inclined manner from silicon carbide to a carbide other than silicon carbide as it leaves the surface of the composite material layer.
Long fiber reinforced silicon carbide member. A cylindrical long fiber reinforced silicon carbide member,
A composite material layer in which silicon carbide long fibers are combined in a silicon carbide matrix;
A graphite intermediate layer formed on the surface of the composite material layer;
A silicon carbide monolithic layer formed on the surface of the graphite interlayer;
A carbide surface layer formed on the surface of the silicon carbide monolithic layer,
The carbide surface layer is formed such that the composition changes in an inclined manner from silicon carbide to a carbide other than silicon carbide as it leaves the surface of the composite material layer.
Long fiber reinforced silicon carbide member. In the carbide surface layer, the carbide other than silicon carbide is at least one selected from titanium carbide, zirconium carbide, hafnium carbide, niobium carbide, and tantalum carbide.
The long fiber reinforced silicon carbide member according to claim 4. A manufacturing method for manufacturing a cylindrical long fiber reinforced silicon carbide member,
Preparing a composite material layer in which silicon carbide long fibers are combined in a silicon carbide matrix;
Forming a graphite surface layer on the surface of the composite material layer,
A method for producing a long fiber reinforced silicon carbide member. In the step of forming the graphite surface layer, the surface of the composite material layer is decomposed by heating to form the graphite surface layer.
The manufacturing method of the long fiber reinforced silicon carbide member of Claim 6. The step of forming the graphite surface layer is performed under a reduced pressure atmosphere.
The manufacturing method of the long fiber reinforced silicon carbide member of Claim 7. The step of forming the graphite surface layer is performed in an atmosphere containing a mixed gas of carbon monoxide and carbon dioxide.
The manufacturing method of the long fiber reinforced silicon carbide member of Claim 7 or 8. In the step of forming the graphite surface layer, the graphite surface layer is formed by thermal chemical vapor deposition.
The manufacturing method of the long fiber reinforced silicon carbide member of Claim 6. In the step of forming the graphite surface layer, after forming the graphite layer by decomposing the surface of the composite material layer by heating, the graphite surface layer is further laminated by thermal chemical vapor deposition. Forming,
The manufacturing method of the long fiber reinforced silicon carbide member of Claim 6. A manufacturing method for manufacturing a cylindrical long fiber reinforced silicon carbide member,
Preparing a composite material layer in which silicon carbide long fibers are combined in a silicon carbide matrix;
Forming a graphite interlayer on the surface of the composite material layer;
Forming a silicon carbide monolithic layer on the surface of the graphite intermediate layer;
Forming a graphite surface layer on the surface of the silicon carbide monolithic layer,
A method for producing a long fiber reinforced silicon carbide member. A manufacturing method for manufacturing a cylindrical long fiber reinforced silicon carbide member,
Preparing a composite material layer in which silicon carbide long fibers are combined in a silicon carbide matrix;
Forming a carbide surface layer on the surface of the composite material layer,
In the step of forming the carbide surface layer, the carbide surface layer is formed such that the composition changes in an inclined manner from silicon carbide to a carbide other than silicon carbide as the distance from the surface of the composite material layer increases.
A method for producing a long fiber reinforced silicon carbide member. A manufacturing method for manufacturing a cylindrical long fiber reinforced silicon carbide member,
Preparing a composite material layer in which silicon carbide long fibers are combined in a silicon carbide matrix;
Forming a graphite interlayer on the surface of the composite material layer;
Forming a silicon carbide monolithic layer on the surface of the graphite intermediate layer;
Forming a carbide surface layer on the surface of the silicon carbide monolithic layer,
In the step of forming the carbide surface layer, the carbide surface layer is formed such that the composition changes in an inclined manner from silicon carbide to a carbide other than silicon carbide as the distance from the surface of the composite material layer increases.
A method for producing a long fiber reinforced silicon carbide member. In the step of forming the carbide surface layer, the carbide surface layer is formed by thermal chemical vapor deposition.
The manufacturing method of the long fiber reinforced silicon carbide member of Claim 13 or 14.

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