JPH0985866A - Manufacture of oblique pore composite material preform - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the interior precipitation and filling of ceramics having the dense center of a plate thickness and porous part at the surface layer by a CVI method by disposing a prepreg added with filler for reducing the porosity at the enter of the plate thickness and laminating prepregs having no filler added on both the surfaces. SOLUTION: The prepreg that C powder having a mean particle size of 2μm of 30wt.%-added as filler for reducing the porosity to a prepreg impregnated with opened fiber material 18ply of carbon fiber in phenol resin is disposed at the center of a plate thickness. Prepregs 2 having no filler added and impregnated with opened fiber material 3ply of carbon fiber in phenol resin are laminated on both the upper and lower surfaces, and cured to form FRP 3. Then, the FRP 3 is baked to manufacture an oblique pore C/C preform 4 that the porosity is obliquely increased from the center of the plate thickness to the outer surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a tilted pore composite material preform in which the pore ratio is gradually increased from the center of the plate thickness to the outer surface.

[0002]

2. Description of the Related Art A composite material having high specific strength and heat resistance is required for a gas turbine blade of an aircraft, an outer plate of a spacecraft and the like. Since such a heat-resistant composite material has a composite structure of high hardness materials, it is not easy to process such as cutting, and it is required to manufacture a material with a predetermined shape and size (shape imparting property) at the molding stage. Has been done. Conventionally, as a high-performance heat-resistant composite material having such a shape-imparting property, CVI has been used.
A ceramic matrix composite (CMC: fiber reinforced ceramics) manufactured by the method is known. In the CVI method, a raw material gas is caused to flow through a preform (preform) obtained by preforming carbon fibers or the like held at a predetermined shape and size and at an arbitrary temperature, and a matrix (matrix) is deposited and filled in the pores of the preform. A composite material is obtained.

By the way, a normal C / C preform is
When the pulse CVI method is carried out, the ceramic may not be deposited and filled up to the center of the plate thickness depending on the size and shape. This is because when the raw material gas permeates through the pores in the surface of the C / C preform and the ceramics are deposited and filled, the pores are clogged in the middle and the raw material gas no longer permeates. In such a case, the obtained C
The / C composite material cannot be expected to have high strength because the central part of the plate thickness is porous. On the other hand, in the densified C / C preform, the surface pores are clogged due to the densification, and it is extremely difficult to internally fill the ceramics by the CVI method. Therefore, C / C due to matrix multidimensionalization
Higher performance of composite materials and higher adhesion of coating film by CVD method cannot be expected.

[0004]

SUMMARY OF THE INVENTION Therefore, according to the present invention, the central part of the plate thickness is dense, the surface layer is porous, the internal precipitation filling of ceramics by the CVI method is easy, and the high adhesion of the coating film by the CVD method is provided. The present invention intends to provide a method for producing a tilted pore composite preform capable of obtaining the above.

[0005]

[Means for Solving the Problems] 1 of a method for manufacturing a tilted pore composite material preform according to the present invention for solving the above problems.
One is the matrix precursor, which has a prepreg added with a filler that reduces the porosity in the center of the plate thickness, and prepregs without filler are laminated on both upper and lower surfaces of the prepreg, and after curing, firing this, It is characterized in that a preform is produced in which the porosity is gradually increased from the center of the plate thickness to the outer surface.

Another method of manufacturing the gradient pore composite material preform of the present invention is to dispose a prepreg containing a filler for reducing the porosity in a matrix precursor in the central portion of the plate thickness and to fill the filler on both upper and lower surfaces thereof. Laminated prepreg without additives, and at least one layer of prepreg with filler added to increase the porosity in the matrix precursor on top and bottom of the prepreg, and after curing, calcination of this prepreg It is characterized by making a preform on the outer surface of which the porosity is gradually increased.

In the above-mentioned two methods for producing a gradient pore composite material preform, a matrix precursor to which a filler is added is a resin having a high residual carbon ratio such as phenol resin,
Alternatively, it is preferably a ceramic precursor. Further, in the above two manufacturing methods, the filler that reduces the porosity is C powder, SiC, or Ti that does not volatilize even when fired.
Carbides such as C and B ₄ C, nitrides such as ZrN and TiN, A
A ceramic powder such as an oxide such as l ₂ O ₃ or Y ₂ O ₃ is preferable. Further, in the latter manufacturing method described above, the filler for increasing the porosity is Al ₄
Metal powders such as Al powders that volatilize as C _{3 and the} like, polymer powders such as polyethylene, nylon, polypropylene, and vinylon that gasify and volatilize during baking, and resins that have a small amount of carbon remaining after baking, that is, a so-called low carbonization yield, for example, It is preferably an epoxy resin or the like.

Another method of manufacturing the graded pore composite material preform of the present invention is a dense carbon fiber or ceramic fiber woven fabric having a high residual carbon content such as phenol resin in the center of the plate thickness. A prepreg, which is impregnated with a resin or a ceramics precursor, to reduce the porosity by firing, is placed on both upper and lower surfaces of the woven carbon fiber or ceramics woven fabric and a resin with a high residual carbon content such as phenol resin. Alternatively, a prepreg which is impregnated with a ceramics precursor or the like to increase the porosity by firing is arranged and laminated, and after curing, this is fired to increase the porosity from the center portion of the plate thickness to the outer surface. It is characterized by making preforms that are increased in an inclined manner.

Yet another method of manufacturing the graded pore composite material preform of the present invention is a resin having a high residual carbon content such as a phenol resin and a woven fabric of 100% carbon fiber or ceramic fiber in the center of the plate thickness. Alternatively, a prepreg impregnated with a ceramics precursor or the like is arranged, and a resin or a ceramics precursor having a high residual carbon rate such as a phenolic resin or the like is added to a woven fabric of carbon fibers or ceramics fibers whose polymer fiber blending ratio is sequentially increased on the upper and lower surfaces thereof. By impregnating and firing, the polymer fibers are gasified and volatilized, and prepregs are arranged so that the porosity is increased and laminated, and after curing, this is fired and the pores are transferred from the center of the plate thickness to the outer surface. It is characterized by making a preform with an increasing rate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to each of the above-described methods for producing a tilted pore composite material preform of the present invention, a preform having a gradually increased porosity from the central portion of the plate thickness to the outer surface can be easily obtained. This inclined pore composite material preform has high strength because the central part of the plate thickness is dense, and since the surface layer is porous, internal precipitation filling of ceramics by the CVI method is easy, and due to the multidimensional matrix. High performance of the inorganic composite material is possible, and since the surface layer of the coating film formed by the CVD method is porous, high adhesion can be obtained by the anchor effect.

[0011]

EXAMPLE One example of the method for producing a gradient pore composite preform of the present invention will be described. A prepreg obtained by impregnating 18 ply of an open fiber material of carbon fiber in a phenol resin is used as a filler for reducing the average porosity. C with a particle size of 2 μm
A prepreg 1 obtained by adding 30 wt% of powder is shown in FIG.
As shown in FIG. 2, the filler-free prepreg 2 in which the open fiber material 3ply is impregnated in phenol resin is laminated on the upper and lower surfaces of the prepreg 2 and cured.
As shown in Fig. 1b, make FRP3, then
3 was fired to produce a tilted pore C / C preform 4 shown in FIG. 1C in which the pore ratio was increased from the center of the plate thickness to the outer surface in a tilted manner.

Next, another embodiment of the method for producing the inclined pore composite material preform of the present invention will be described. The prepreg obtained by impregnating the open woven fabric 12ply of carbon fiber in phenol resin has a reduced porosity. Prepreg 1 obtained by adding 30 wt% of C powder having an average particle size of 2 μm as a filler
2a is placed in the center of the plate thickness as shown in FIG.
Filler-free prepreg 2 impregnated with y was laminated, and prepreg impregnated with 1 ply of carbon fiber plain weave in phenol resin was laminated on both upper and lower surfaces with Al powder having an average particle size of 5 μm as a filler to increase the porosity. 30 wt
% Of the prepreg 5 is laminated and cured,
2b is produced, and then this FRP 6 is fired to produce an inclined pore C / C preform 7 shown in FIG. 2C in which the pore ratio is increased from the center of the plate thickness to the outer surface in an inclined manner. It was

Next, another embodiment of the method for manufacturing the inclined pore composite material preform of the present invention will be described. In the center portion of the plate thickness, as shown in FIG. The prepreg 8 formed by impregnating the opened fabric 18ply of the phenol resin with the phenol resin is arranged, and the prepreg 9 obtained by impregnating the plain fabric 1ply of the coarse carbon fiber with the phenol resin is laminated on the upper and lower surfaces thereof, and cured. As shown in FIG. 3b, an FRP 10 is made, and then this FRP 10 is fired,
An inclined pore C / C preform 11 shown in C of FIG. 3 was produced in which the pore ratio was gradually increased from the center of the plate thickness to the outer surface.

Next, another embodiment of the method for producing a tilted pore C / C preform of the present invention will be described.
As shown in Fig. 4a, 100% carbon fiber is used in the center of the plate thickness.
Of the open fiber woven fabric 12ply of the prepreg 12 impregnated with phenol resin, and a carbon fiber having a blending ratio of polymer fiber, nylon fiber (which may be polyethylene fiber in this example) of 40% on both upper and lower surfaces thereof. Open textile 3p
Prepreg 13 obtained by impregnating ly with phenol resin
And a prepreg 14 obtained by impregnating a phenol resin with a plain fabric 1 ply of carbon fiber having a mixed spinning ratio of nylon fiber (which may be polyethylene fiber) set to 80% is laminated on both upper and lower surfaces thereof and cured. 4B, an FRP 15 was formed, and then this FRP 15 was fired to increase the pore ratio from the center of the plate thickness to the outer surface in an inclined manner. The inclined pore C / C shown in FIG. 4C. I made a preform 16.

The tilted pores C of Examples 1 to 4 thus prepared
/ C preforms 4, 7, 11, 16 and conventional ordinary C / C preforms, that is, prepregs obtained by impregnating carbon fiber open woven fabric 24ply with phenol resin are cured to form FRP, which is then baked. C / with a uniform porosity obtained by
When the C preform and the preform characteristics were measured, the results shown in Table 1 below were obtained.

[0016]

[Table 1]

As can be seen from Table 1 above, various fillers are added to the matrix precursor, the weave density of the woven fabric is changed, or the woven fabric mixed with the polymer fiber is used, whereby the pores after firing are The volume content Vp of V can be changed. Further, there is no great difference in the average pore diameter of the surface between the inclined pore C / C preforms of Examples 1 to 4 and the conventional C / C preform.

Actually, in the inclined pore C / C preforms of Examples 1 to 4 and the conventional example C / C preform,
When pulse CVI was carried out to deposit and fill SiC inside, and the pore ratio and tensile strength before and after that were measured, the results shown in Table 2 below were obtained.

[0019]

[Table 2]

As can be seen from Table 2 above, the graded pore C / C preforms of Examples 1 to 4 have a decreased pore ratio after CVI and an improved tensile strength, while the C / C of the conventional example has C
The preform has a small decrease in pore rate and a low improvement rate in tensile strength. This is because the graded pore C / C preforms of Examples 1 to 4 have the raw material gas deeply infiltrated into the interior by performing CVI, and SiC is deposited and filled to make the interior dense, while the C / C of the conventional example. This is because the preform is clogged due to precipitating and filling of SiC in the surface layer portion by performing CVI at an early stage, and the raw material gas does not permeate from that portion and the inside remains porous.

[0021]

As can be seen from the above description, according to the method for manufacturing a gradient pore composite material preform of the present invention, the center portion of the plate thickness is dense and has high strength, and the ceramic is porous by the CVI method toward the surface. It is possible to improve the performance of the inorganic composite material by diversifying the matrix, and it is possible to obtain high adhesion of the coating film by CVD method by the anchor effect at the pores of the surface layer. A superior graded pore composite preform can be manufactured.

[Brief description of drawings]

FIG. 1 shows one embodiment of a method for producing a tilted pore C / C preform of the present invention, in which a to c are process diagrams.

FIG. 2 shows another embodiment of the method for producing a tilted pore C / C preform of the present invention, in which a to c are process drawings.

FIG. 3 shows another embodiment of the method for producing a tilted pore C / C preform of the present invention, in which a to c are process drawings.

FIG. 4 shows still another embodiment of the method for producing a tilted pore C / C preform of the present invention, in which a to c are process drawings.

[Explanation of symbols]

1 C powder-added prepreg 2 Filler-free prepreg 3 FRP 4 Gradient pore C / C preform 5 Al powder-added prepreg 6 FRP 7 Gradient pore C / C preform 8 Weaving dense carbon fiber woven fabric Arranged prepreg 9 Plain woven woven carbon fiber prepreg 10 FRP 11 Gradient pore C / C preform 12 Prepreg with 100% carbon fiber spread fabric 13 40% mixed spinning ratio 14 prepreg on which an open woven fabric of carbon fiber is arranged 14 prepreg on which a plain woven fabric of carbon fiber having a blending ratio of 80% is arranged 15 FRP 16 inclined pore C / C preform

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // B29K 61:04 105: 06 307: 04 309: 02 501: 00 505: 02 507: 04 509 : 04 B29L 9:00 (72) Inventor Kazuhiro Nishi 1 Kawasaki-cho, Kakamigahara-shi, Gifu Kawasaki Heavy Industries, Ltd. Gifu factory

Claims (7)

[Claims] 1. A prepreg in which a filler for reducing the porosity is added to a matrix precursor is arranged in the central portion of the plate thickness, and prepregs with no filler are laminated on both upper and lower surfaces of the prepreg, and after curing, the prepreg is baked. A method for producing a tilted pore composite material preform, characterized in that a preform having a gradually increased porosity from the center of the plate thickness to the outer surface is produced. 2. A prepreg in which a filler for reducing the porosity is added to the matrix precursor is arranged in the central portion of the plate thickness, prepregs without a filler are laminated on the upper and lower surfaces of the prepreg, and the matrix precursor is sequentially formed on the upper and lower surfaces of the prepreg. At least one layer of prepreg added with a filler that increases the porosity is laminated and cured, and then baked,
A method for producing a tilted pore composite material preform, characterized in that a preform having a gradually increased porosity from the center of the plate thickness to the outer surface is produced. 3. The production of a gradient pore composite material preform according to claim 1, wherein the matrix precursor to which the filler is added is a resin having a high residual carbon rate such as a phenol resin, or a ceramics precursor. Method. 4. The filler for reducing the porosity is C powder, which does not volatilize even when fired, carbide such as SiC, TiC, B ₄ C, nitride such as ZrN and TiN, Al ₂ O, Y ₂ O _{3 and the} like. 3. The method for producing a tilted pore composite material preform according to claim 1, wherein the method is a ceramic such as an oxide. 5. The filler for increasing the porosity is A when firing.
_3. A metal powder such as Al powder that volatilizes as l ₄ C _{3 and the} like, a polymer powder that gasifies and volatilizes during firing, and a resin that remains little as carbon or ceramics during firing. For manufacturing a graded-pore composite preform. 6. The porosity is lowered by impregnating a woven carbon fiber or ceramics fiber woven fabric with a resin having a high residual carbon ratio such as phenol resin or a ceramics precursor in the central portion of the plate thickness, and firing it. The prepreg made in this way is placed, and the upper and lower surfaces of the prepreg are impregnated with a woven carbon fiber or ceramic fiber woven fabric with a resin having a high residual carbon rate such as phenol resin or a ceramic precursor to increase the porosity by firing. Arrange and stack the prepreg made in
A method for producing a tilted pore composite material preform, characterized in that, after hardening, this is fired to form a preform in which the pore ratio is gradually increased from the center portion of the plate thickness to the outer surface. 7. A prepreg formed by impregnating a woven fabric of 100% carbon fibers or ceramics fibers with a resin having a high residual carbon rate such as phenol resin or a ceramics precursor is disposed in the central portion of the plate thickness, and both upper and lower surfaces thereof are arranged. In addition, carbon fiber or ceramic fiber woven fabrics with an increased polymer fiber blending ratio are impregnated with a resin with a high residual carbon ratio such as phenol resin or a ceramics precursor, and the polymer fibers are gasified and volatilized by firing and the porosity is high. The laminated prepregs are laminated, cured, and then fired to form a preform with an obliquely increased porosity from the center of thickness to the outer surface. Composite preform manufacturing method.