JP2010100889A - Method of forming silicon carbide film to surface of carbon base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently form a silicon carbide film on the surface of a carbon base material without causing cracks nor peeling after the formation of the silicon carbide film. <P>SOLUTION: The method of supporting the carbon base material 1 in a state where a prescribed part in the surface 1b of the carbon base material 1 is brought into contact with a supporting fixture 4, and forming the silicon carbide film 5 on the surface 1b of the carbon base material 1, comprises: a stage where the carbon base material 1 in which a hole 1a is formed at the prescribed part with which the supporting fixture 4 is brought into contact, is prepared; a stage where an insertion member 2 made of a material in a kind same as that of the carbon base material 1 and having a dimensional shape capable of being inserted into the hole 1a, and in which a silicon carbide film 3 is beforehand formed on the surface 2a connected with the surface 1b of the carbon base material 1 when being inserted into the hole 1a, is prepared; and a stage where the insertion member 2 is inserted into the hole 1a of the carbon base material 1 in such a manner that the insertion member 2 is directly brought into contact with the hole 1a, and, in a state where the supporting fixture 4 is brought into contact with the surface of the insertion member 2 in which the silicon carbide 3 has been formed, and the carbon base material 1 is supported, the silicon carbide film 5 is formed on the surface 1b of the carbon base material 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of forming a silicon carbide film on a surface of a carbon substrate by supporting the carbon substrate in a state where a predetermined portion of the surface of the carbon substrate such as graphite is in contact with a support jig. It is.

  In a carbon base material made of graphite or carbon fiber reinforced carbon composite material (C / C composite material), a silicon carbide film is applied to the surface of the carbon base material by a CVD method or the like for the purpose of imparting oxidation resistance. May be formed.

  In such a case, the silicon carbide film is formed on the surface of the carbon base material by supporting the carbon base material in a state where a predetermined portion of the surface of the carbon base material is in contact with the support jig. In this case, since the silicon carbide film is not formed on the surface of the carbon base material in contact with the support jig, the silicon carbide film formation reaction is interrupted, the position of the carbon base material is shifted, and the support jig is It was necessary to devise such as changing the contact point.

  In Patent Document 1, as a method of solving such a problem, a silicon carbide plate is previously fitted or adhered to a place where the support jig comes into contact, and the support jig is brought into contact with this part. A method of forming a silicon carbide film in a state has been proposed.

  However, when the silicon carbide plate is fitted, the carbon base material and the silicon carbide plate have different coefficients of thermal expansion, which causes a problem such as a crack occurring in the fitting part of the carbon base material due to the difference in the coefficient of thermal expansion.

Further, when the silicon carbide plate is bonded to the surface of the carbon substrate, there arises a problem that a crack or the like due to the adhesive layer occurs.
JP 2000-129444 A

  An object of the present invention is to provide a method for forming a silicon carbide film on the surface of a carbon substrate, which can efficiently form the silicon carbide film on the surface of the carbon substrate without causing cracks or peeling after the formation of the silicon carbide film. It is to provide.

  The present invention is a method for supporting a carbon substrate in a state where a predetermined portion of the surface of the carbon substrate is in contact with a support jig, and forming a silicon carbide film on the surface of the carbon substrate, the support jig A carbon base material having a hole formed at a predetermined position where the carbon base material abuts, and a fitting member made of the same material as the carbon base material and having a size and shape that can be fitted into the hole. A step of preparing an insertion member in which a silicon carbide film is previously formed on a surface continuous with the surface of the carbon base material, and inserting the insertion member so that the insertion member directly contacts the hole of the carbon base material. And a step of forming a silicon carbide film on the surface of the carbon base material in a state where the carbon base material is supported by contacting a support jig to the surface of the fitting member on which the film is formed.

  In the present invention, a hole is formed at a predetermined location on the surface of the carbon base material with which the support jig abuts, and the hole is made of the same kind of material as the carbon base material and has a dimension and shape that can be fitted into the hole. A fitting member having a silicon carbide film formed in advance on a surface continuous with the surface of the carbon base material, and a support jig is brought into contact with the surface of the fitting member. Then, a silicon carbide film is formed on the surface of the carbon base material while supporting the carbon base material. Since a silicon carbide film is formed in advance at a predetermined location where the support jig abuts, even if the silicon carbide film is not formed at the location where the support jig abuts, it is continuous on the surface of the carbon substrate. A silicon carbide film can be formed in a state. Accordingly, the entire surface of the carbon substrate can be continuously coated.

  In the present invention, since the insertion member made of the same material as the carbon base material is inserted into the hole of the carbon base material, there is no difference in the thermal expansion coefficient between the carbon base material and the insertion member, and the thermal expansion coefficient is The stress based on the difference does not cause a crack or the like in the carbon base material or the insertion member at the place where the insertion member is inserted. For this reason, a silicon carbide film can be efficiently formed on the surface of a carbon substrate, without generating a crack and exfoliation in a silicon carbide film after silicon carbide film formation.

  The carbon substrate in the present invention is not particularly limited as long as it is a substrate made of a carbon material, but is preferably a substrate made of graphite, more preferably a substrate made of isotropic graphite. is there. In the case of using a base material made of isotropic graphite, it is not particularly necessary to match the crystal orientation of the carbon base material with the fitting member to be inserted into the hole of the carbon base material, which is particularly suitable for the method of the present invention.

  In the present invention, the shape of the hole formed in the carbon base material and the shape of the fitting member are not particularly limited, but from the viewpoint of ease of processing the hole and the fitting member, ease of fitting, etc. It is preferable that

  Moreover, the dimension of the hole formed in the carbon base material and the fitting member can be set in consideration of the area of the portion where the support jig contacts the surface of the carbon base material. For example, when the shape of the fitting member is a columnar shape, it is generally preferable that the diameter is about 3 to 15 mm. Further, the depth of the hole and the height of the fitting member are generally within the range of 1 to 50% of the thickness of the carbon substrate.

  Further, when the shape of the hole and the fitting member is a columnar shape, the diameter of the fitting member is preferably slightly larger than the diameter of the hole, preferably 0.01 to 0.1 mm larger in diameter, and more preferably. Is preferably 0.02 to 0.06 mm larger.

  When the fitting member is too large to be fitted into the hole of the carbon base material, the outer peripheral portion of the fitting member may be gradually thinned until it can be fitted into the hole of the carbon base material.

  In the present invention, a silicon carbide film is formed in advance on the surface of the fitting member continuous with the surface of the carbon base material when the fitting member is fitted into the hole. The method for forming the silicon carbide film is not particularly limited, but in general, the silicon carbide film can be formed by a CVD method such as a thermal CVD method. Note that no silicon carbide film is formed on the surface of the fitting member in contact with the inside of the hole of the carbon base material. Therefore, the surface of the fitting member in contact with the inside of the hole of the carbon base material is in a state where the same kind of material as that of the carbon base material is exposed.

  As a method of forming the silicon carbide film only on the predetermined surface of the fitting member, after forming the silicon carbide film on the surface of the member serving as the raw material of the fitting member, a method of cutting a portion other than the portion where the silicon carbide film is left Alternatively, a silicon carbide film is formed in a state where the surface of the fitting member on which the silicon carbide film is not formed is masked with a resist film or the like, and after the silicon carbide film is formed, the resist film is removed, leaving the silicon carbide film only on a predetermined surface. The method etc. are mentioned.

  In the present invention, the method for forming the silicon carbide film on the surface of the carbon substrate is not particularly limited, but in general, a CVD method such as a thermal CVD method is used.

  In the present invention, the thickness of the silicon carbide film is not particularly limited, and examples thereof include a thickness of 20 to 200 μm. A similar range can be given to the thickness of the silicon carbide film formed on the surface of the fitting member.

  The carbon substrate of the present invention is characterized in that a silicon carbide film is formed by the method of the present invention.

  Since the carbon substrate of the present invention has a silicon carbide film formed by the method of the present invention, it can be efficiently produced without cracking or peeling after the silicon carbide film is formed.

  According to the present invention, a silicon carbide film can be efficiently formed on the surface of a carbon substrate without causing cracks or peeling after the silicon carbide film is formed.

  Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited to the following examples.

Example 1
FIG. 2 is a perspective view showing the carbon substrate used in this example. The carbon substrate 1 is a substrate made of isotropic graphite. The diameter is 200 mm and the thickness is 30 mm.

  As will be described later, the carbon base material 1 is supported by bringing a supporting jig into contact with the surface 1b of the carbon base material 1, and a silicon carbide film is formed on the surface 1b of the carbon base material 1 in this state. The

  According to the present invention, holes 1a are formed at three locations where the support jig comes into contact. As will be described later, a fitting member 2 having a size and shape that can be fitted into the hole 1a is fitted into the hole 1a.

  FIG. 1A is a cross-sectional view showing the vicinity of the hole 1 a of the carbon substrate 1. The surface 1b of the carbon substrate 1 is an f200 plane, and holes 1a are formed at three locations on the surface 1b as shown in FIG. The hole 1a has a cylindrical shape and is formed to have a diameter of 10 mm and a depth of 10 mm.

  FIG.1 (b) is sectional drawing which shows a fitting member. A silicon carbide film 3 is formed on the surface 2 a of the fitting member 2. Silicon carbide film 3 has a thickness of 50 μm. Silicon carbide film 3 is formed by a thermal CVD method.

  The diameter of the fitting member 2 is 10.04 mm, and is formed with a dimension 0.04 mm larger than the diameter 10 mm of the hole 1a. Moreover, the thickness of the fitting member 2 is 10 mm.

  FIG. 1C is a cross-sectional view showing a state in which the insertion member 2 is inserted into the hole 1 a of the carbon base material 1. As shown in FIG. 1C, the surface 2 a of the fitting member 2 fitted into the hole 1 a of the carbon base material 1 is a surface that is continuous with the surface 1 b of the carbon base material 1. The fitting member 2 is inserted into the hole 1a under pressure. As a method of applying pressure, for example, there is a method of inserting the fitting member 2 into the hole 1a by hand, or when it is difficult to insert by hand, a method of putting a backing plate and driving it with a mallet or the like.

  FIG. 1 (d) is a cross-sectional view showing a state in which the carbon base material 1 is supported by bringing the contact portion 4 a of the support jig 4 into contact with the silicon carbide film 3 of the fitting member 2. In this state, a silicon carbide film is formed on the surface 1b of the carbon substrate 1 by a thermal CVD method.

  FIG. 1E is a cross-sectional view showing a state in which the silicon carbide film 5 is formed on the surface 1 b of the carbon base material 1. Silicon carbide film 5 has a thickness of 50 μm.

  FIG. 1 (f) shows a state where the carbon substrate 1 is removed from the support jig 4. As shown in FIG. 1 (f), the silicon carbide film 5 is not formed at the place where the contact portion 4 a of the support jig 4 is in contact, but this portion is formed on the surface of the fitting member 2. Since the formed silicon carbide film 3 is present, the entire surface 1 b of the carbon substrate 1 can be continuously covered with the silicon carbide films 5 and 3.

  FIG. 3 is a cross-sectional view showing an example of the prior art.

  As shown in FIG. 3A, when a silicon carbide film is formed on the surface 1b of the carbon base material 1 in a state where the contact portion 4a of the support jig 4 is in contact, as shown in FIG. In this state, silicon carbide film 5 is formed. When the carbon base material 1 is removed from the support jig 4, as shown in FIG. 3C, the silicon carbide film 5 is formed on the part where the contact part 4 a of the support jig 4 is in contact. In other words, the entire surface 1 b of the carbon substrate 1 cannot be continuously covered with the silicon carbide film 5.

  According to the present invention, as shown in FIG. 1 (f), the silicon carbide film 3 is present in the portion where the contact portion 4 a of the support jig 4 is in contact. The entire surface 1 b can be covered with silicon carbide films 5 and 3.

(Comparative Example 1)
As shown in FIG. 3 (a), a carbon base material 1 in which holes 1a are not formed is used, and a contact portion 4a of a support jig 4 is brought into contact with and supported on the surface 1b of the carbon base material 1. In this state, the silicon carbide film 5 was formed until the film thickness became 25 μm. Thereafter, the carbon substrate 1 was removed from the support jig 4, and the place where the contact portion 4a of the support jig 4 contacts was moved to form the remaining silicon carbide film with a film thickness of 25 μm. Thereby, since the contact portion 4a of the support jig 4 is in contact with the formation of the silicon carbide film for the first time, the silicon carbide film can be formed in the portion where the silicon carbide film was not formed. As a result, the silicon carbide film 5 could be continuously formed on the entire surface 1b of the carbon substrate 1.

(Comparative Example 2)
The dimensional shape of the fitting member 2 was formed with a dimensional shape slightly smaller than that of Example 1. Specifically, it was formed to have a diameter of 9.8 mm and a height of 9.9 mm. A carbon cement as an adhesive was applied on the surface of the fitting member 2 on which the silicon carbide film 3 was not formed, and inserted into the hole 1 a of the carbon substrate 1.

  Next, in the same manner as in Example 1, while supporting the carbon substrate 1 with the support jig 4 so that the contact portion 4a of the support jig 4 is in contact with the silicon carbide film 3 of the fitting member 2, the silicon carbide is supported. The film 5 was formed to a film thickness of 50 μm by one coating.

(Comparative Example 3)
In this comparative example, the insertion member 2 made of bulk silicon carbide was produced as the insertion member 2. The fitting member 2 made of silicon carbide was formed such that its dimensions were a diameter of 10 mm and a height of 10 mm. The insertion member 2 made of silicon carbide is inserted into the hole 1a of the carbon base material 1 in the same manner as in the first embodiment, and then the contact portion 4a of the support jig 4 is inserted in the same manner as in the first embodiment. In a state where the carbon base material 1 is supported so as to contact the member 2, the silicon carbide film 5 is formed so as to have a film thickness of 50 μm by one coating.

(Comparative Example 4)
A disk made of silicon carbide having a diameter of 10 mm and a thickness of 50 μm was produced. This silicon carbide disc was produced by forming a silicon carbide film on a separate carbon substrate by a thermal CVD method and then cutting it.

  As shown in FIG. 4, the silicon carbide plate 6 produced as described above is bonded to the surface 1 b of the carbon base material 1 where the holes 1 a are not formed using carbon cement as an adhesive, and the bonded carbonization is performed. The silicon carbide film 5 was formed to a thickness of 50 μm by one coating while supporting the silicon plate 6 by contacting with the contact portion 4 a of the support jig 4.

[Measurement of NG number]
In Example 1 and Comparative Examples 1 to 4, after the silicon carbide film was formed, the number of samples in which cracks or peeling occurred in the silicon carbide film or the like was measured. In Example 1 and Comparative Examples 1 to 4, the number of samples was set to 5. Therefore, the number of NG out of 5 samples was measured. The measurement results are shown in Table 1. Table 1 also shows the number of samples and the number of coatings of the silicon carbide film.

  In addition, NG in the comparative example 2 is what a crack generate | occur | produced in the contact bonding layer between a fitting member and a hole. In NG in Comparative Example 3, cracks occurred from the periphery of the hole into which the insertion member made of silicon carbide was inserted. In NG in Comparative Example 4, cracks occurred from the portion of the adhesive layer to which the silicon carbide plate was bonded.

  As is clear from the results shown in Table 1, in Example 1, the number of NGs was 0 and the number of coatings was 1. On the other hand, in Comparative Example 1, the NG number was 0, but it was necessary twice as the number of coatings. In Comparative Examples 2 to 4, the number of times of coating was one, but cracks and peeling occurred in the silicon carbide film and the like, and the silicon carbide film could not be continuously formed on the entire surface of the carbon substrate. It was.

  As described above, according to the present invention, the silicon carbide film can be efficiently formed on the surface of the carbon base material without causing cracks or peeling after the silicon carbide film is formed.

  In addition, in the said Example, although the shape of the hole formed in a carbon base material and the shape of the insertion member inserted in this hole are made into the column shape, this invention is not limited to such a shape. Moreover, although the place which a support jig contacts is made into three places and the hole is formed in three places on the surface of a carbon base material, this invention is not limited to supporting in three places.

Sectional drawing which shows the manufacturing process of one Example according to this invention. The perspective view which shows the carbon base material and insertion member in one Example according to this invention. Sectional drawing which shows the manufacturing process of a prior art example. Sectional drawing for demonstrating a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Carbon base material 1a ... Hole of carbon base material 1b ... Surface of carbon base material 2 ... Insertion member 2a ... Surface of insertion member 3 ... Carbon film formed on the surface of insertion member 4 ... Support jig 4a ... Support jig 5 ... Silicon carbide film 6 ... Silicon carbide plate

Claims (4)

A method of supporting the carbon substrate in a state where a predetermined portion of the surface of the carbon substrate is in contact with a support jig, and forming a silicon carbide film on the surface of the carbon substrate,
Preparing the carbon base material in which a hole is formed at the predetermined location where the support jig abuts;
An insertion member made of the same kind of material as the carbon base material and having a size and shape that can be inserted into the hole, and carbonized in advance on a surface continuous with the surface of the carbon base material when inserted into the hole. Preparing a fitting member formed with a silicon film;
The insertion member is inserted so that the insertion member is in direct contact with the hole of the carbon base material, and the support jig is brought into contact with the surface of the insertion member on which the silicon carbide film is formed so that the carbon base material is attached. Forming the silicon carbide film on the surface of the carbon base material in a supported state, and forming the silicon carbide film on the surface of the carbon base material.   2. The method for forming a silicon carbide film on the surface of a carbon substrate according to claim 1, wherein the carbon substrate is made of graphite.   The method for forming a silicon carbide film on the surface of a carbon substrate according to claim 2, wherein the graphite is isotropic graphite. A carbon substrate comprising a silicon carbide film formed by the method according to claim 1.

Images