JPH01111830A - Reinforcing fiber for production of fiber-reinforced composite metallic material - Google Patents

Abstract

PURPOSE:To develop reinforcing fibers having excellent performance as the raw material for a fiber-reinforced composite metallic material by providing a composite metallic layers contg. specific hard particles around fibers made of carbon, stainless steel or ceramics as precursor fibers. CONSTITUTION:The carbon fibers and stainless steel fibers 10 as the precursor fibers are wound, in the state of isolating the fibers from each other, on a jig 16 having two pieces of arm parts 12, 14 in a plating cell. The fibers are then immersed in a plating bath 20 ot Cu, Ni, etc., contg. fine pieces 18 of the hard particles of Al2O3, SiO2, TiO2, Cr4C, etc., or the hard particles such as SiC whiskers and Si3N4 whiskers or graphite, MoS2, etc., having self-lubricity and are thereby electroplated with the precursor fibers 10 are cathode. The reinforcing fibers 24 which have the metal plating layers 22 uniformly dispersed and incorporated with the above-mentioned fine pieces 18 at about 18vol.% on the surfaces of the precursor fibers 10 are cut to a suitable length. The fibers are then unidirectionally oriented and are compressionmolded. The reinforcing fibers for the fiber reinforced composite metallic material consisting of Al, etc., as the matrix metal is thus produced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to fiber-reinforced metal composite materials, and more particularly to the reinforcing fibers used in their manufacture.

Conventional techniques such as those described in Japanese Unexamined Patent Application Publication No. 58-93845 jointly filed by the applicant of the present application and another applicant (such as a composite reinforcement reinforced with reinforcing fibers and particles such as solid lubricant particles) Conventionally, in the production of composite materials, a molded body is formed from a mixture of reinforcing fibers and particles, and the molded body is used for pressure casting.

Problems to be Solved by the Invention However, when producing a composite material by such a method, the presence of particles between the reinforcing fibers prevents the molten matrix metal from penetrating into the molded body. Furthermore, it is difficult to produce a molded body in which the particles are uniformly dispersed, and because the particles are moved by the molten matrix metal during the pressure infiltration stage, it is difficult to produce a molded body in which the particles are uniformly dispersed. The problem is that it is difficult to manufacture composite materials that are

In view of the above-mentioned problems in manufacturing composite materials reinforced with reinforcing fibers, particles, etc. by conventional methods, the present invention has been developed to easily produce composite materials in which fine pieces such as particles are uniformly dispersed. The aim is to provide reinforcing fibers that can be manufactured.

Means for Solving the Problems According to the present invention, a fiber-reinforced metal comprising precursor fibers and a composite metal coating layer covering the precursor fibers and having fine pieces of another material dispersed therein. This is achieved by reinforcing fibers for the production of composite materials.

Functions and Effects of the Invention The reinforcing fiber of the present invention is composed of a precursor fiber and a composite metal coating layer that covers the precursor fiber and has fine pieces of other materials dispersed therein. When pressure casting is performed, the metal of the composite metal coating layer is melted by the molten matrix, and the fine pieces of other materials are uniformly dispersed in the matrix in the vicinity of the precursor fibers, so that the particles It is possible to easily produce a composite material in which the following components are uniformly dispersed.

Furthermore, even if the precursor m-fiber is a fiber that has poor wettability with respect to the molten matrix metal, such as a ceramic fiber, by selecting an appropriate metal for the composite metal coating layer, the wettability of the precursor fiber can be improved and the composite A fiber-reinforced metal composite material can be manufactured without producing defects such as defective parts.

Furthermore, in the conventional manufacturing method of composite materials reinforced with reinforcing fibers, particles, etc., it is difficult to control the volume fraction of particles, etc., but in the present invention, the composite metal coating layer By controlling the volume fraction of fine particles of other materials contained in the plating bath, for example when the application of a composite metal coating layer is carried out by plating, the amount of fine particles of other materials in the plating bath, pH 1
By appropriately controlling plating conditions such as temperature and current density, the volume fraction of particles, etc. can be easily controlled to a desired value.

According to one particular feature of the invention, the fine particles of the other material are hard particles or whiskers, and when such reinforcing fibers are used, the precursor fibers ensure the strength of the composite material and 1J due to hard particles and whiskers
J6! Abrasion resistance can be improved. Examples of hard particles include alumina particles, chromium carbide particles, silica particles, titanium oxide particles, zirconium oxide particles, silicon carbide particles, silicon nitride particles, titanium carbide particles, tungsten carbide particles, and diamond particles. There are silicon carbide whiskers, silicon nitride whiskers, etc.

According to another detailed feature of the invention, the particles of other material are self-lubricating particles or whiskers. According to such reinforcing fibers, the strength and wear resistance of the composite material can be ensured by the precursor fibers, and the amount of wear of the mating material itself and the mating material can be reduced by the self-lubricating particles and whiskers. Particles having self-lubricating properties include boron nitride particles, graphite particles, molybdenum disulfide, tungsten disulfide, etc., and whiskers having self-lubricating properties include potassium titanate whiskers.

The metal constituting the composite metal coating layer may be arbitrarily selected depending on the material of the precursor fiber used and the matrix metal to which the reinforcing fiber of the present invention is applied, such as nickel, nickel alloy, copper, chromium, iron, iron alloy, cobalt,
gold, silver, zinc, etc., and the precursor fibers are carbon fibers, silicon carbide fibers, alumina fibers, alumina-silica fibers,
It may be boron fiber, tungsten fiber, stainless steel fiber, etc. Further, the composite metal coating layer may be formed by any method such as plating or thermal spraying, but plating is particularly preferred since it can form a layer with a uniform thickness.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

Example 1 As shown in FIG. 1, carbon fiber (continuous fiber) 10 ("M2O" manufactured by Toshi Co., Ltd., fiber diameter 6.5 μm) was used as a precursor fiber, and had two arm parts 12 and 14. The jig 16 is wound with each winding being spaced apart from each other, and the coil is coated in a copper plating bath 20 (copper sulfate) in which alumina particles 18 (average particle size: 0.5 μm) are dispersed as fine pieces of another material. 20
0g/no, sulfuric acid 50g/no, bath temperature 30℃),
Voltage 2v1 cathode current density 6 using carbon fiber as one electrode
Electroplating was carried out at A/dlQ', thereby coating the carbon fibers with a composite metal coating layer having a thickness of about 1 μm.

FIG. 2 is an illustration showing a cross section of the reinforcing fiber 24 thus formed, and the composite metal coating layer 22 was made of copper in which alumina particles 18 with a volume fraction of about 20% were dispersed.

Next, in order to evaluate the performance of the reinforcing fibers thus formed, the portion of the reinforcing fibers 24 extending between the arms 12 and 14 was cut to a length of 100+ am, as shown in FIG. By oriented them in one direction and compression molding them, a fiber molded body 26 having dimensions of 10×20×1001nffi and a reinforcing fiber volume ratio of about 50% was formed. Next, as shown in FIG. 4, the fiber molded body 26
is filled into a stainless steel case 28 that is open at both ends, preheated to approximately 600°C, placed in a mold 30 for high-pressure casting, and filled with aluminum alloy (JI) at 740°C.
Pour molten metal 32 of S standard AC4C) and place the molten metal into mold 30.
Approximately 1000 kg/
Pressure was applied at ca+2, and the pressurized state was maintained until the molten metal completely solidified.

A section reinforced with reinforcing fibers was cut out from the ingot thus formed, and its cross section was observed under a microscope. It was found that alumina particles were uniformly dispersed around the carbon fibers, and it was found that there was poor penetration of the aluminum alloy. It was found that no such defects occurred.

Example 2 As shown in FIG. 5, alumina fibers 36 (manufactured by DuPont, average fiber diameter 20μ, average fiber length 31HI11) as precursor fibers were mixed with boron nitride particles 38 (as fine pieces of other materials). Electroless plating was performed by dispersing the alumina fibers in a nickel plating bath 40 ("Blue Schumer" manufactured by Nippon Ganizen Co., Ltd.) in which particles (average particle size: 3 μm) were dispersed, thereby coating the alumina fibers with a composite metal coating layer.

FIG. 6 is a sectional view showing the reinforcing fibers 42 thus formed, and shows the composite metal coating layer 4 covering the alumina fibers 36.
4 was made of nickel in which boron nitride particles 38 with a volume fraction of about 25% were dispersed, and the thickness was about 8 μm.

Next, in order to evaluate the performance of the reinforcing fibers formed as described above, the reinforcing fibers were dispersed in an aqueous solution of colloidal silica as an inorganic binder, compression molding was performed on the dispersion, and the resulting compression molded product was dried. As a result, as shown in FIG. 7, a fiber molded body 4 having dimensions of 70×70×10+nm and a volume percentage of reinforcing fibers 42 of 15% is obtained.
6 was formed.

Next, after preheating the fiber molded body 46 to 400° C., it is placed in a mold 30 for high pressure casting, as shown in FIG.
Aluminum alloy (JIS standard AC) heated to 730℃ is placed inside the mold.
The molten metal 48 of 8A) was poured, and the molten metal was pressurized to about 1000 kg/cm2 by the plunger 34 fitted into the mold 30, and the pressurized state was maintained until the molten metal completely solidified. A section reinforced with reinforcing fibers was cut out from the ingot thus formed, and its cross section was observed under a microscope. As a result, boron nitride particles were uniformly dispersed around the alumina fibers, indicating poor penetration of the aluminum alloy. It was found that no such defects occurred.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to these embodiments, and various other embodiments are possible within the scope of the present invention. This will be obvious to those skilled in the art.

[Brief explanation of the drawing]

Fig. 1 is an illustration showing a plating process in which a composite metal coating layer is formed on carbon fibers as precursor fibers, Fig. 2 is a cross-sectional view showing reinforcing fibers formed by the plating process shown in Fig. 1, FIG. 3 is a perspective view showing a fiber molded body formed from the reinforcing fibers shown in FIG. 2, and FIG. A sectional view showing the casting process, Figure 5 is an illustration showing the plating process in which a composite metal coating layer is formed on the alumina fiber as a precursor fiber by electroless plating, and Figure 6 is the plating process shown in Figure 5. 7 is a cross-sectional view showing reinforcing fibers formed by
FIG. 8 is a perspective view showing a fiber molded body formed from the reinforcing fibers shown in FIG. It is. 10...Carbon fiber, 12.14...Arm part, 16
... Jig, 18... Alumina particles, 20... Plating bath. 22... Reinforcing fiber, 24... Composite metal coating layer, 26
... Fiber molded body, 28 ... Case, 30 ... Mold, 32 ... Molten aluminum alloy, 34 ... Plunger, 36 ... Alumina fiber, 38 ... Boron nitride particles, 40 ... Plating bath, 42 ... Reinforced fiber, 4
4... Composite metal coating layer, 46... Fiber molded body, 48
...Aluminum alloy molten metal patent applicant: Toyota Motor Corporation representative
Attorney Patent Attorney Tsuyoshi Akashi 8 Figure 4 10 - Carbon fiber 24... Reinforced fiber 18...
Alumina particles 26...Fiber molded body 20...Plating; Valley 32...Aluminum alloy; Volume;
Easy 22... Composite metal coating layer No. 5 Figure 7 Section 36... Alumina fiber 4 38... Poron nitride particles 43 40... Plating valley 48... 42...
Reinforcement fiber Figure 6 Figure 8 Aluminum alloy I8-1

Claims (3)

[Claims] (1) A reinforcing fiber for producing a fiber-reinforced metal composite material comprising a precursor fiber and a composite metal coating layer covering the precursor fiber and having fine pieces of another material dispersed therein. (2) In the reinforcing fiber for manufacturing a fiber-reinforced metal composite material according to claim 1, the fine pieces of the other material are hard particles or whiskers. Reinforced fiber for use. (3) The reinforcing fiber for manufacturing a fiber-reinforced metal composite material according to claim 1, wherein the fine pieces of the other material are particles or whiskers having self-lubricating properties. Reinforced fibers for composite material production.