JPS60162748A - Carbon fiber/carbon/metal composite material and production thereof - Google Patents

Abstract

PURPOSE:To produce a carbon fiber/carbon/metal composite material having high ordinary-temp. strength and good heat resistance by casting a molten metal into the open pores of the carbon fiber/carbon composite material consisting of carbon fibers and carbon matrix having the open pores. CONSTITUTION:Carbon fibers such as polycarylonitrile or the like and a carbonizable material such as a phenolic resin or the like are heated and pressurized in dies to form a composite molding. The composite molding is then heated to about 600-3,000 deg.C in inert gaseous flow to carbonize the above-mentioned carbonizable material and to form the carbon matrix having the pores open with each other around the carbon fibers by which the carbon fiber/carbon composite body is obtd. The melt of Al, Mg, Cu, Sn, Zn, Pb, Ni or an alloy consisting essentially of at least one l kind thereof is cast under the pressure exerted thereto into the above-mentioned open pores of such composite body and is solidified. The carbon fiber/carbon/metal composite material is thus easily obtd.

Description

Detailed Description of the Invention (a) Technical Field of the Invention The present invention relates to a composite material of carbon fiber, carbon, and metal.

(b) Conventional technology and its drawbacks Carbon fiber and metal composite material Fl (hereinafter referred to as CF RM) has higher specific strength and specific modulus than materials made only of metal, so it is necessary to make it lighter. It is attracting attention in various fields. However, such CFRM suffers from a significant drop in bullet impact near the melting point of the metal, making it difficult to maintain its shape as a material. In other words, CFRM has low heat resistance.

On the other hand, composite materials of carbon fiber and carbon (hereinafter referred to as CF
Since RC is a material essentially consisting of carbon, it has higher heat resistance than CFRM. Furthermore, the active characteristics are also good. For this reason, it is attracting attention as a drawing shrine in fields such as the aerospace industry. However, C.F.
RC has high power at room temperature, but CFRM is not expensive. WA3 involves impregnating an aggregate of carbon fibers with a carbonizable substance such as phenolic resin and firing them to form a carbon matrix.
There is a problem with the m method because such a method creates a large number of voids in the carbon matrix. In other words, the generation of voids is a major obstacle to improving the strength of CFRC.

(c) Purpose of the present invention The purpose of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide carbon lAl1111 with high bullet holes at room temperature and good heat resistance.
/ Carbon/metal composite material and its manufacturing method.

(d) Structure of the present invention In order to achieve the above object, the present invention is made of a composite material of carbon fiber, carbon, and metal, the carbon and metal form a matrix, and the carbon A carbon fiber/carbon/metal composite material is provided, wherein the matrix has pores communicating with each other, and the metal fills the communicating pores of the carbon matrix. Also,
In the present invention, as a method for manufacturing such a composite material, a step of forming a carbon matrix having interconnected pores around carbon 11M to obtain a carbon fiber/carbon composite I material, and a step of forming the carbon fiber/carbon composite I material, A method for manufacturing a carbon fiber/carbon/metal composite material is provided, which comprises the steps of: pouring molten metal into the communicating holes of the carbon composite material and solidifying the molten metal.

To explain this invention in more detail, the composite material of this invention uses carbon fibers as so-called reinforcing fibers and carbon and metal as a matrix. Thus, the carbon matrix has pores that communicate with each other. In other words, the carbon matrix is shaped like a sponge or an open-cell resin. The metal fills the communicating pores of the carbon matrix. Therefore, this metal matrix is also morphologically the same as the carbon matrix. Therefore, the composite material of this invention exhibits a strength between that of conventional CFRM and CFRC at relatively low temperatures, and when the temperature approaches the melting point of the metal forming the matrix, it develops the characteristics of a carbon matrix and becomes CFRC. Shows similar strength.

That is, the AM strength does not decrease as much as that of conventional CFRM, and it exhibits good heat resistance.

In the above, the carbon fiber is polyacrylonitrile-based,
It may be either rayon-based or pitch-based, and may be carbonaceous or graphite. The diameter of such carbon fibers is on the order of 3 to 15 microns. Also,
The form is length 0.05~5II1m1 preferably 0.2
It may be short fibers of about 31 Il or continuous fibers. It may be processed into a sheet form such as woven fabric, felt, or mat. Therefore, the carbon fibers may be present in the carbon and metal matrix with completely random orientation in eight directions (short fibers, felt, etc.).
(in the case of mats), they may be arranged in any specific direction (in the case of continuous fibers or woven fabrics).

The carbon that forms the matrix is the so-called soft carbon (
These include soft carbon), hard carbon, and pyrolytic carbon. Soft carbon is obtained by carbonizing polycyclic aromatic compounds such as heavy petroleum oil, pitch, and anthracene, and vinyl chloride resin, which are carbonized through one layer.

Moreover, hard carbon is obtained by carbonizing thermosetting resins such as phenol resins, furan resins, and acrylic resins, which are carbonized in a solid state. Furthermore, pyrolytic carbon is obtained by passing hydrocarbon gas such as methane, propane, benzene, acetylene, etc. into a hydrogen gas stream at 700 to 2000°C.

The metal forming the matrix may be aluminum, magnesium, copper, tin, zinc, lead, nickel, etc., or a metal containing at least one of these as a main component, such as an aluminum-silicon alloy, an aluminum-copper alloy, or a magnesium alloy. - Alloys such as aluminum alloy, magnesium-zinc alloy, copper-tin alloy, copper-zinc alloy, etc.

The composite @ material of this invention first makes CFRC, and then
It can be manufactured by pressurizing and impregnating RC with molten metal, releasing the pressure, or solidifying the molten metal while being pressurized. Next, a preferred manufacturing method will be shown.

That is, when the carbon fibers are short fibers, the short fibers are mixed with a carbonizable substance such as phenol resin, furan resin, pitch, or a solution thereof.

Next, the above mixture is put into a mold in the shape of the desired composite material, and the mixture is poured into a mold with a density of 1 to 1000 Kg/Cl112, preferably 20 Kg/Cl112.
~50~50 while applying pressure of ~500Kg/cg+2
It is heated to 0° C. and maintained at that temperature for several tens of minutes to several hours to obtain a composite of short fibers and carbonizable material.

Next, the above composite was heated in an inert gas stream at 600 to 3000°C, preferably 1000 to 300°C with a fingernail.
The carbonizable material is carbonized by heating to 0°C, and CF RC
get.

When the carbon fibers are in the form of continuous fibers or sheets, they are impregnated with the carbonizable substance or its solution, cut into appropriate sizes or shapes, and laminated in a mold. The following steps are similar to those for short fibers.

Next, after putting the CFRC into a mold, molten metal that will become a metal matrix is poured into the mold.
Impregnate the CFRC by applying a pressure of KO/am2. The composite material of the present invention is obtained by solidifying the molten metal with the release of pressure or with the application of pressure.

As described above, the composite material of the present invention has high strength at room temperature and excellent heat resistance. It also has high specific strength and specific modulus. Therefore, it can be used for various purposes. For example, it is suitable for aerospace applications such as various parts for aircraft, rockets, and artificial satellites. Furthermore, brake shoes for automobiles, aircraft, etc. can be constructed. Furthermore, it is suitable as a material for pistons, piston pins, apex seals, connecting rods, etc. of internal combustion engines.

Furthermore, it can be used to construct current collector sliders for railway vehicles, brushes for rotating electric machines, contacts for electrical equipment, and the like.

(E) Effects of this invention Since the matrix of the composite material of this invention is made of carbon and metal, it mainly exhibits the characteristics of CFRM, which is high strength at relatively low temperatures, and also exhibits the characteristics of CFRM, which is high strength at relatively low temperatures. The main feature of CF RC is its high heat resistance. Not only does it have high strength at room temperature, but it also has excellent heat resistance. Moreover, such a composite material can be manufactured by pouring molten metal into CFRC and solidifying it, so existing equipment for CFRC and CFRM can be used, and special equipment is not particularly required.

Example Carbon m miscellaneous "Trading card" M40 fabric manufactured by Toshi Co., Ltd. (
Fabric weight: approximately 2000/m2) was impregnated with a 30% by weight methanol solution of phenolic resin, dried at room temperature, and then cut to a length of 100 mm and a width of 50+ m.

Next, 70 pieces of the above-mentioned cut pieces were stacked in a mold having a cavity of the same size with the warp directions of the fabrics aligned, and the cut pieces were stacked together in a mold having a cavity of the same size as the cut pieces.
The temperature increases at a rate of about 200℃ per hour, and the temperature rises by about 1
Hold for a period of time to harden the phenolic resin, length 100m1
．． Carbon rim with width 5Qsw and thickness 10.5sm [/IC phenolic resin composite] /:.

Next, the above composite was heated at about 200°C for about 100 hours to fully cure the phenolic resin, and then the temperature was raised to about 1500°C at a rate of about 30°C/hour in a nitrogen gas stream. The phenol resin was carbonized by holding for about 1 hour to obtain CFRC having a carbon fiber volume content of about 70%.

Next, the above-mentioned CFRG was placed in a mold, and molten aluminum/silicon alloy (silicon m: approximately 7% by weight) (temperature: approximately 750°C) was poured into the mold at approximately 500K (J/cm2).
The composite material of the present invention was obtained by impregnating CFRC with a pressure of

Next, the surface of the composite material was polished and observed with an optical microscope. The observation results are shown in Figure 1 as a photograph (magnification: 600x). In FIG. 1, what looks a little black are the carbon fibers that make up the warp and weft of the fabric, and what looks even darker is the carbon matrix. What is white and has Yonezawa is an aluminum/silicon alloy matrix.
When the n+ test piece was cut out and its three-point bending strength was measured using a universal testing machine 15-2000 manufactured by Shimadzu Corporation, it was approximately 40 KO/112. Also, 800
The bending strength S at each temperature T up to 100°C was measured at every 100°C, and as shown by the solid line in FIG. 2, there was no extremely large decrease even at high temperatures, indicating good heat resistance.

Comparative Example 1 The same carbon fiber fabric used in the example was made with a length of 100 m.
70 pieces of fabric were stacked with the warp direction aligned and placed in a mold.The molten aluminum/silicon alloy was poured into the mold in the same manner as in the example and solidified. In this way, a CFRM having a carbon fiber volume content of about 70% was obtained.

The room temperature bending strength of this CFRM was measured in the same manner as in the example and was approximately 60 Ko/mga2. In other words, the normal temperature bullet holes were higher than those of the examples.

However, as shown by the dotted line in Figure 2, its bending strength gradually begins to decrease around 400°C, and
When the temperature exceeds 570°C, the temperature decreases significantly, and finally becomes lower than that of the present invention at around 570°C.

Comparative Example 2 The CF RC obtained in Example was placed in a pressure vessel, the pressure inside the vessel was reduced to approximately 5111 HQ, and then a 30% by weight methanol solution of phenol resin was injected at approximately 100K.

The above CFRC was impregnated with a pressure of /ci2.

Next, the CFRC was removed from the container and placed in air for about 60 minutes.
After drying at ℃ for about 24 hours, heating at about 200℃ for about 100 hours to harden the phenol resin, and then heating it in a nitrogen gas stream at a rate of about 0℃/hour to about 1500℃. The temperature was held for approximately 1 hour to carbonize the phenolic resin. This operation is repeated twice and the so-called 'tfA
Density CFRC was obtained.

When such a CFRC was subjected to the same test as in the example, the bending strength at room temperature was only about 25 kg/a+s2, despite being a high-density CFRC, which was higher than that of the example and comparative example 1. But it was very low.

However, the bending strength remained almost unchanged up to about 800° C., as shown by the dashed line in FIG.

[Brief explanation of the drawing]

Figure 1 is an optical micrograph (magnification: 60048) showing the shape of fibers on the polished surface of the composite material of the present invention, and Figure 2 is a composite material of the present invention, CFRM and CFR.
Temperature T (°C) and bending strength S measured for C
It is a J graph showing the relationship between (KO/+ua2). Patent applicant: Toshi Co., Ltd. Figure 2 Figure 7 (τ)

Claims (2)

[Claims] (1) Made of a composite material of carbon fiber, carbon, and metal, the carbon and metal forming a matrix,
A carbon fiber/carbon/metal composite material, wherein the carbon matrix has pores communicating with each other, and the metal fills the communicating pores of the carbon matrix. (2) forming a carbon matrix having interconnected pores around the carbon fibers to obtain a carbon fiber M/carbon composite material, and pouring WJ191 metal into the communicating holes of the carbon IIat11/carbon composite material; A method for producing a carbon fiber M/carbon/gold FfhNJ composite material, the method comprising a solidifying step.