JPH0416568A - Method for joining carbon fiber reinforced carbon composite member - Google Patents

Abstract

PURPOSE:To obtain a joined part which is light in weight, high in strength, and has excellent heat resistance and oxidation resistance by forming Al films on the joint surfaces of carbon fiber reinforced carbon composite members, bringing the respective joint surfaces into contact with each other and subjecting the members to a high-temp. treatment in a nitriding atmosphere. CONSTITUTION:The Al films 3 are formed by an ion vapor deposition method over the entire part of the surface parts contg. the joint surfaces 1a, 2a of the carbon fiber reinforced carbon composite members 1, 2. The respective joint surfaces 1a, 2a are then butted against each other and the members are subjected in this state to hot isotropic compression in an Ar atmosphere, by which the Al is sufficiently impregnated over the entire surface part of the composite members 1, 2 and the Al interposed in the joint surfaces 1a, 2a is melted and integrated to each other. These composite members 1, 2 are then subjected to the hot isotropic compression in an N2 atmosphere to form the Al films 3 to aluminum nitride films 4 and to interpose the aluminum nitride in the joint surfaces 1a, 2a of the composite members 1, 2. The joint in which the two members are joined is thus obtd.

Description

[Detailed description of the invention] [Purpose of the invention]

(Field of Industrial Application) The present invention is a carbon fiber ffi/carbon fiber that is lightweight, has high strength, and has excellent heat resistance and oxidation resistance, and is used for joining carbon wt male/carbon composite members. This paper relates to a bonding force method for composite members. (Conventional technology) In recent years, the required characteristics for various structural members have become even more severe, and conventional metal and resin materials are no longer able to adequately meet these required characteristics. Materials and fine fiber #! / Carbon composite materials have been developed and are now being put into practical use. Conventionally, as a method of joining the above-mentioned ceramic materials with a sealing property, for example, as shown in FIG. 2, stepped portions 11a, The stepped portion 11a of one of the ceramic members 11 formed by the bolt 12a and fixed by the bolt 13, and the stepped portion 12a of the other ceramic member 12 also fixed by the bolt 14.
In some cases, a heat-resistant material 15 is filled between the ceramic parts 15 and 12 to maintain sealing properties, or as shown in FIG. There have been attempts to join by forming a fused joint 16 by heating with a high-density engineering heat source such as a beam or an electron beam. (Problem to be Solved by the Invention) However, attempts were made to apply this method to bonding carbon wire fil/carbon composite members based on the bonding method for ceramic members 11 and 12 shown in FIGS. 2 and 3. In this case, the problem is that sufficient bonding strength cannot be obtained with the joint structure shown in FIG. 2, in which the joint structure is secured using bolts 13 and 14 and sealing performance is ensured by filling the joint end face with heat-resistant material 15. Furthermore, the bonding method using a high-voltage heat source shown in Figure 3 has a problem in that it cannot be applied to bonding carbon fiber/carbon composite members due to limitations on the materials. The challenge was to solve these problems.

[Structure of the invention]

(L stage for solving the problem) A method for joining carbon fiber/carbon composite members according to the first claim of the present invention is as follows: 1. One carbon edge fig/carbon composite member and the other carbon fiber/carbon composite member For joining, after forming an aluminum film on at least the joining surfaces or the entire surface of the one and the other carbon edge #l/carbon composite members, the inner carbon fiber/carbon composite members are brought into contact with each other at their respective joining surfaces. The aluminum film is changed into an aluminum nitride film by subjecting it to a high temperature treatment in a nitriding atmosphere, and the carbon fiber #I/carbon composite member is bonded via the aluminum nitride. The method for joining carbon fiber/carbon composite members according to the second claim of the present invention is such that when joining one carbon fiber/carbon composite member and another carbon fiber/carbon composite member, Carbon rim! /After forming an aluminum film on at least the joint surface or the entire surface of the carbon composite member, the inner carbon fiber/carbon composite member is subjected to high temperature pressure treatment in a non-nitriding inert atmosphere to form the carbon edge III/
A step of promoting impregnation of aluminum on the surface of the carbon composite member and a step of bringing the two carbon fiber m/carbon composite members into contact with each other at their respective bonding surfaces are performed in succession, and then a high temperature treatment is performed in a nitriding atmosphere. Accordingly, the aluminum film is changed to an aluminum nitride film, and both the carbon fibers and the II/carbon composite member are bonded via the aluminum nitride. It is characterized by a structure in which an aluminum film is formed on at least the joint surface or the entire surface of the composite member by ion vapor deposition, and the above-mentioned structure of the carbon edge fit/carbon composite member joining method solves the above-mentioned conventional problems. It is used as a means to do so. Figure 1 shows a carbon fiber/carbon composite member (C/
This figure shows an embodiment of the method for joining C/C members), and shows the order in which one C/C member 1 and the other C/C member 2 are joined. The manufacturing method of the C/C members 1 and 2 shown in FIG. 1(a) applied in the present invention is not particularly limited. The matrix binder is phenolic,
Furano type, pitch type, etc. are used, and carphone 8
Materials such as m/phenol, graphai) [i/phenol, carbon fiber Am/pitch, graphite Jia fiber/pitch, etc. are carbonized or graphitized by primary firing, and pitch impregnation and firing are repeated to further increase the T degree. The resin-char method, the vapor deposition method of depositing carbon produced by thermally decomposing hydrocarbons onto aggregates knitted with carphone mm or graphite fibers, and combination methods thereof are applied, and the present invention The manufacturing method of the C/C member 1.2 used in is not particularly limited. Then, an aluminum film 3 is formed on at least the joint surfaces or the entire surface of the C/C members 1 and 2, as shown in FIG. 1(b). The aluminum film 3 is formed on at least the joint surface or the entire surface of the C/C member 1.2 by induction heating with aluminum powder placed on at least the joint surface or the entire surface of the C/C member 1.2, C/C in molten aluminum melt
The members 1 and 2 may be immersed to form an aluminum film 3 on at least the joint surface or the entire surface of the C/C member 1.2, or ion blasting may be performed on at least the joint surface or the entire surface of the C/C member 1.2. Although it is possible to form the aluminum film 3 by thermal spraying or the like, it is particularly preferable to form the aluminum film 3 on the C/C member 1.
Ion vapor deposition (IV
D) The aluminum film 3 is deposited to a thickness of, for example, 50 to 100μ by a metal ion implantation method called ion implantation method.
It should be formed to a thickness of about m. Next, both the C/C members 1 and 2 are attached to each joint surface 1a,
Step 2a of bringing them into contact with each other and, more preferably, applying high temperature pressure treatment to both the C/C members 1 and 2 in a non-nitriding inert atmosphere to impregnate the surface of the C/C member 1.2 with aluminum. The process of translating the process is carried out one after the other. That is, when carrying out this high temperature pressure treatment, the first
As shown in FIG. 1(b), the C/C members 1 and 2 on which the aluminum film 3 is formed are separated (including the case where they are treated separately), or as shown in FIG. The C/C members 1 and 2 on which the film 3 has been formed are brought into contact with each other at their joint surfaces 1a and 2a, and the C/C member 1
, 2 in a non-nitriding inert atmosphere to obtain the above C
The impregnation of aluminum into the C/C member 1.2 at least on the joint surface or the entire surface of the C/C member 1.2 is promoted. In this case, an argon atmosphere is used as the non-nitriding inert atmosphere.
At a temperature of about 1000℃, 1800-2500kgf/
By applying high temperature pressure treatment at a pressure of about cm2 for about 60 to 120 minutes, impregnation of aluminum on at least the joint surface or the entire surface of the C/C member 1.2 is promoted. As described above, the step of promoting aluminum impregnation by high-temperature pressure treatment may be performed with the C/C member 1.2 separated, as shown in the first [ff1(b)].
Alternatively, as shown in FIG. 1(C), the C/C member 1.2 may be butted with its joint surfaces 1a and 2a, and when the C/C member 1.2 is butted, the butted portion is melted by melting the aluminum. of aluminum is integrated. Next, the C/C members 1 and 2 are impregnated with aluminum as described above to obtain a mechanical anchoring effect.
The aluminum film 3 is brought into contact with the bonding surfaces 1a and 2a and subjected to high temperature treatment in a nitriding atmosphere to change the aluminum film 3 into an aluminum nitride film 4 as shown in FIG. 1(d). Forming an aluminum nitride film 4 on at least the joint surfaces or the entire surface of the C members 1 and 2, and joining both the C/C members 1 and 2 via the aluminum nitride film 4 formed between the respective joint surfaces 1a and 2a. do. In this case, using 100% N2 scum as the nitriding atmosphere,
For example, at a temperature of about 1800 to 2500℃, 1800℃
~120~1 with a pressure of about 2500kgf/cm'
The aluminum film 3 is changed into the aluminum nitride film 4 by heat treatment for about 80 minutes. (Action of the invention) The method for joining carbon m-fiber/carbon composite member according to the present invention is as follows:
When joining one carbon fiber/carbon composite member and the other carbon [1/carbon composite member], an aluminum film is formed on at least the joint surfaces of the one and the other carbon fiber ill/carbon composite member, and then Accordingly, a step of treating both carbon fibers M/carbon composite member under high temperature pressure in a non-nitriding inert atmosphere to promote impregnation of aluminum on the surface of the carbon fiber II/carbon composite member, and both carbon fibers j1 /The steps of bringing the carbon composite members into contact with each other at their joint surfaces are carried out one after the other, and then the aluminum film is changed into an aluminum nitride film by performing high temperature treatment in a nitriding atmosphere, and the carbon fibers are removed. Since the carbon composite member is bonded via the aluminum nitride,
The aluminum nitride film penetrates into the carbon fiber/carbon composite member and provides a mechanical anchoring effect, resulting in good adhesion and strong bonding strength, making it difficult to cause separation. Since the aluminum nitride film has such a strong bonding force and a small coefficient of thermal expansion that forms the surface, it has extremely good heat resistance and oxidation resistance, and the bonding force at the joint part is also sufficiently large. The mechanical strength of the structure is carbon J.
ii! The Jl/carbon composite member is sufficiently secured, and the composite member has a joint portion with high joint strength, and the main body portion also has high strength and excellent heat resistance and oxidation resistance. The decomposition point of aluminum nitride is as high as about 2000°C. For example, in an environment where it is exposed to a high temperature of about 1700°C for a long time of about 4 hours, some aluminum nitride is oxidized with a higher melting point of about 2015°C. It changes to aluminum and provides better heat resistance. (Example) Thickness 1.5m forming a planar shape as shown in Figure 1 (a)
Joint surfaces 1a and 2a of carbon fiber/carbon composite member 1.2 of m
As shown in FIG. 81(b), an aluminum film 3 having a thickness of about 1100 kL was formed on the entire surface portion including industrial pure aluminum by ion vapor deposition (CIVD) method. Next, carbon m, which formed the aluminum film 3,! /
As shown in FIG. 1(C), the carbon composite members 1 and 2 were brought into contact with each other at their joint surfaces 1a and 2a, and heated at a temperature of 700°C and a pressure of about 2000 kg in an Ar atmosphere.
Hot isostatic pressing (HIP) is carried out under conditions of f/cm2 for approximately 90 minutes to impregnate the entire surface portion of the carbon fiber/carbon composite member 1.2 with aluminum. In addition, the aluminum interposed between the joint surfaces 1a and 2a was melted and integrally bonded to each other. Next, the aluminum is impregnated and the bonding surface 1a is
, 2a is aluminum or carbon fiber fused together/
Carbon composite member 1.2 was heated at a temperature of approximately 2000°C and a pressure of approximately 2000kgf/cm' at 9MJ in an N2 atmosphere.
The carbon fiber/
Bonding in which an aluminum nitride film 4 is formed on the entire surface portion of the carbon composite member 1.2, and aluminum nitride is interposed between the bonding surfaces 1a and 2a of both carbon and fiber M/carbon composite members 1.2 to join them. Got the fitting. When we investigated the tensile strength of this joint, we found that it was 1
Carbon 1! The tensile strength of the ffi/carbon composite members 1 and 2 was approximately 70% higher than that of the main body.

【Effect of the invention】

The method for joining carbon ill, II/carbon composite members according to the present invention is such that when joining one carbon fiber/carbon composite member and the other carbon fiber/carbon composite member, the carbon edge i/carbon After forming an aluminum film on at least the joint surface of the composite member, if necessary, the carbon fiber/carbon composite member is subjected to high temperature pressure treatment in a non-nitriding inert atmosphere to form the carbon edge! The step of promoting impregnation of aluminum on the surface of the l/carbon composite member and the step of bringing the two carbon fiber/carbon composite members into contact with each other at their joint surfaces are performed one after the other, and then heated at high temperature in a nitriding atmosphere. Since the aluminum film is changed into an aluminum nitride film by treatment, and the carbon fiber/carbon composite member is bonded via the aluminum nitride,
The aluminum nitride film penetrates into the carbon fiber/carbon composite member and provides a mechanical anchoring effect, resulting in good adhesion, strong bonding strength, and resistance to peeling. The aluminum nitride film with high strength and low coefficient of thermal expansion forms the surface, so it has extremely good heat resistance and oxidation resistance, and the bonding force at the joint part is also sufficiently large. The mechanical strength of the structure is sufficiently ensured by the carbon fiber/carbon composite member, which has a joint part with high joint strength, and the main body part is also a composite material with high strength and excellent heat resistance and oxidation resistance. A significantly greater effect is obtained in that the parts and their joining joints are obtained.

[Brief explanation of drawings]

Figures 1 (a), (b), (c) and (d) are cross-sectional explanatory diagrams showing the embodiment of the method for joining carbon fiber/carbon composite members according to the present invention in the order of steps, and Figures 2 and 3 are conventional FIG. 2 is a cross-sectional explanatory diagram illustrating a joining structure of ceramic members. 1.2... Carbon fiber/carbon composite member, 4... Aluminum nitride film. Patent applicant Nissan Motor Co., Ltd.

Claims (3)

[Claims] (1) When joining one carbon fiber/carbon composite member and the other carbon fiber/carbon composite member, after forming an aluminum film on at least the joint surfaces of the one and the other carbon fiber/carbon composite members, the Both carbon fiber/carbon composite members are brought into contact with each other at their bonding surfaces and subjected to high temperature treatment in a nitriding atmosphere to change the aluminum film to an aluminum nitride film and to remove both carbon fiber/carbon composite members. A method for joining carbon fiber/carbon composite members, characterized in that joining is performed via the aluminum nitride. (2) When joining one carbon fiber/carbon composite member and the other carbon fiber/carbon composite member, after forming an aluminum film on at least the joint surfaces of the one and the other carbon fiber/carbon composite members, the A step of treating both carbon fiber/carbon composite members under high temperature and pressure in a non-nitriding inert atmosphere to promote impregnation of aluminum on the surface of the carbon fiber/carbon composite member; The process of bringing the joint surfaces into contact with each other is performed in succession,
A carbon fiber/carbon composite member characterized in that the aluminum film is then subjected to high temperature treatment in a nitriding atmosphere to change the aluminum film to an aluminum nitride film, and both carbon fiber/carbon composite members are joined via the aluminum nitride. Joining method. (3) At least on the joint surface of the carbon fiber/carbon composite member,
The method for manufacturing a carbon fiber/carbon composite member according to claim 1 or 2, wherein the aluminum film is formed by an ion vapor deposition method.