JPH057219Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) This invention uses a carbon fiber/carbon composite material made by bonding carbon or graphite fibers with a carbon or graphite matrix. Regarding cylindrical members, especially carbon fibers suitable for use in axially symmetrical structures such as rocket nozzles.
This invention relates to a cylindrical member made of carbon composite material.

(Prior art) Carbon fiber/carbon composite materials can be produced using a method in which a preform made of carbon fiber is repeatedly impregnated with pitch and fired (resin-char method), or a method in which pyrolytic carbon is chemically deposited ( It is obtained through a composite treatment using methods such as CVD (CVD method), and is lightweight and hardly wears out or loses strength due to heat, making it suitable for use in parts exposed to harsh thermal environments, such as rocket nozzles. ing. The fiber orientation of this carbon fiber/carbon composite material varies depending on the means of forming the preform, such as continuous carbon fiber filaments wound circumferentially;
Laminated with cross-woven carbon fibers,
These include short carbon fibers (chop-shaped fibers) pressed into a mold, or continuous carbon fiber filaments rolled up in multiple dimensions. Impregnated with resin and hardened using an autoclave or hot press.

Such carbon fiber/carbon composite materials are described in, for example, "Current Status and Problems of Research and Development of New Composite Materials Volume 1 FRP Edition" produced by Overseas Technical Data Research Institute.
, pages 46 and 47, and pages 30 and 30 of “Tetsu to Hagane No. 70, No. 14,” published by the Japan Iron and Steel Institute in October 1984.
It is described on page 31.

(Problem to be solved by the invention) However, in the case of conventional carbon fiber/carbon composite materials such as those mentioned above, when a preform is formed by winding continuous carbon fiber filaments, the inter-fiber spacing is very large. Although the fibers become dense, it becomes difficult for the binder to penetrate, which may reduce the bonding strength between the fibers and the binder, resulting in peeling between the fibers. In addition, when a preform is formed by laminating carbon fiber cloth, if a composite treatment is performed, for example by a microwave/chir method, the carbon fibers will be formed by the gas generated from the thermosetting resin or the shrinkage of the resin. Cracks (interlayer delamination) are likely to occur between the layers that are not reinforced, and there is a risk that the interlayer shear strength will decrease. Furthermore, when a preform is formed by compressing short carbon fibers, the fibers are naturally not continuous and the bonding force mainly relies on the binder, so the strength decreases more significantly than among the above methods. If a preform is formed by winding continuous carbon fibers in multiple directions, high strength can be obtained, but the problem is that it is extremely difficult to manufacture and the manufacturing cost is extremely high. It was hot.

(Purpose of the invention) This invention was made by paying attention to these conventional problems, and in particular targets a cylindrical member that is an axially symmetrical structure such as a rocket nozzle.
Carbon fiber/carbon composite that has good bonding between each layer and can maintain sufficient strength, especially in the circumferential direction, and can be easily manufactured at low cost. The object is to provide a cylindrical member made of material.

[Structure of the invention] (Means for solving the problem) The cylindrical member made of carbon fiber/carbon composite material according to this invention is similar to a carbon fiber filament in which the fibers are oriented in the circumferential direction by being wound in the circumferential direction. It is characterized in that it is formed by performing a composite treatment on a preform formed by alternately laminating in the radial direction carbon fiber cloth that is wound in the circumferential direction and oriented in the direction in which the fibers intersect. In the case of the above configuration, the preform includes one formed only of carbon fiber filaments and cloth, or one formed by impregnating and hardening with thermosetting resin at the time of formation, and the filament and cloth are made of carbon fibers. This includes those consisting only of carbon fibers or those containing reinforcing fibers other than carbon fibers. In addition, examples of the compounding treatment include a range-char method, a CVD method, and a method that combines both.

(Example) This invention will be explained below based on the drawings.

The accompanying drawing is a diagram illustrating an embodiment of this invention, and shows a preform formed for the purpose of making a rocket nozzle material.

That is, this preform 1 includes a carbon fiber filament 2 which is continuously wound around the axis A in the circumferential direction so that the fibers are oriented in the circumferential direction, and a carbon fiber filament 2 which is also wound in the circumferential direction so that the fibers intersect vertically and horizontally. It is made by laminating carbon fiber cloths 3 oriented in the same direction alternately in the radial direction, and has a hollow portion 4 on its axis that will later become a nozzle hole. In forming this preform 1, a mandrel (not shown) corresponding to the hollow portion 4 is rotatably held, and a carbon fiber impregnated with a thermosetting resin such as a phenolic resin is attached to this mandrel. The filament 2 is regularly wound in the circumferential direction (substantially perpendicular to the axial direction) under constant tension to form a first layer in which the fibers are oriented in the circumferential direction. Next, the carbon fiber cloth 3 is similarly impregnated with a thermosetting resin and laminated on the carbon fiber filament 2 to form the next layer in which the fibers are oriented in the crosswise and vertical directions. After the carbon fibrous filament 2 and the carbon fibrous cloth 3 are laminated alternately in the radial direction to a predetermined thickness, the laminate is heated at 100 to 240° C. while being pressurized to perform a hardening treatment.

In addition, as a composite treatment, the preform 1 is gradually heated in the range of 450 to 900°C to perform carbonization treatment, and then gradually heated in the range of 2000 to 2900°C to be graphitized. Pitch material is impregnated into a sparse state due to the generation of gas due to thermal decomposition of the thermosetting resin in the above treatment, and carbonization and graphitization are performed again. Then, by repeating the impregnation of pitch material, carbonization treatment, and graphitization treatment until a predetermined specific gravity value (approximately 1.5 to 1.6) is obtained, a cylindrical member made of carbon fiber/carbon composite material is obtained.
This cylindrical member made of carbon fiber/carbon composite material is later finished into a rocket nozzle through a cutting process and the like.

The above carbon fiber/carbon composite material cylindrical member is
A carbon fibrous filament 2 wound in the circumferential direction with the fibers oriented in the circumferential direction and a carbon fibrous cloth 3 wound in the same circumferential direction with the fibers oriented in the intersecting direction alternate in the radial direction. Since a preform 1 is used in which the carbon fiber filament 2 is laminated to form a layer of a predetermined thickness, the carbon fiber cloth 3 is sufficiently impregnated with a thermosetting resin to bond the fibers and the carbon fiber filament 2. The bonding with the resin (binder) is good, and for the carbon fiber cloth 3, each layer is reinforced by the carbon fiber filament 2, which provides a dense state between the fibers, reducing interlayer shear. There is no concern that the strength will decrease. Further, the carbon fiber/carbon composite material cylindrical member does not require complicated work such as winding the carbon fiber filament 2 of the preform 1 in a spiral manner, and the circumference of the carbon fiber filament 2 is not required. It is easy to manufacture because it can be simply wound in one direction.

In the above embodiment, the carbon fiber filament 2 and the carbon fiber cloth 3 were impregnated with a thermosetting resin in advance to form the preform 1, but the preform 1 was formed without impregnating the resin. It is also possible to perform a composite treatment in which carbon produced by thermally decomposing hydrocarbons is chemically deposited on the preform. In addition, in the illustrated case, one of the longitudinal and lateral fibers forming the carbon fibrous cloth 3 is aligned with the fiber direction (circumferential direction) of the carbon fibrous filament 2, but the longitudinal and lateral fibers of the carbon fibrous cloth 3 Another example is that the fibers are stacked at an angle of about 45 degrees with respect to the fiber direction of the carbon fiber filament 2. Furthermore, although the application example of the carbon fiber/carbon composite material cylindrical member is not limited to the above-mentioned example, it is possible to laminate carbon fiber filament 2 and carbon fiber cloth 3 wound in the circumferential direction. Because it is an axially symmetrical structure, it has extremely high strength in the circumferential direction, making it extremely suitable for rocket nozzles that need to envelop supersonic gas jets that reach temperatures of approximately 3000°C. Become something.

[Effects of the invention] As explained above, according to the carbon fiber/carbon composite material cylindrical member of this invention, the carbon fiber filament is wound in the circumferential direction and the fibers are oriented in the circumferential direction. The structure is made by applying a composite treatment to a preform formed by alternately laminating carbon fiber cloth in the radial direction with carbon fiber cloth oriented in the direction in which the fibers intersect, so that the entire fiber layer is made of the same fiber layer. Compared to conventional carbon fiber/carbon composite materials using preforms, by utilizing the mutual advantages of different layers, the bond between each layer is better and maintains sufficient strength. Since the fibers are oriented in the circumferential direction, the strength in the circumferential direction can be particularly sufficient. Furthermore, compared to carbon fiber/carbon composite materials made of multidimensionally oriented fibers, It provides similar strength and is easier to manufacture at a much lower cost.

[Brief explanation of drawings]

The accompanying drawing is a perspective view illustrating a carbon fiber/carbon composite preform in one embodiment of this invention. 1... Preform, 2... Carbon fiber filament, 3... Carbon fiber cloth.

Claims (1)

[Scope of utility model registration request] Formed by laminating alternately in the radial direction a carbon fiber filament that is wrapped in the circumferential direction and has fibers oriented in the circumferential direction, and a carbon fiber cloth that is similarly wrapped in the circumferential direction and has fibers oriented in the intersecting direction. A cylindrical member made of carbon fiber/carbon composite material, characterized in that it is formed by subjecting a preform to composite treatment.