JPS60184652A - Manufacture of fiber-reinforced metal - Google Patents

Abstract

PURPOSE:To manufacture fiber-reinforced metal excellent in adhesive strength between the metal and the fiber by putting the fiber for reinforcement in a vacuum reaction vessel, supplying the vapor of a specified metal compound and attaching the metal to the fiber through decomposing the metal compound with low temp. plasma. CONSTITUTION:Fiber 6 such as single fiber of glass, boron, carbon, silicon carbide, silicon nitride, alumina, boron carbide, steel, tungsten, etc. and whisker or fabric made of those and nonwoven fabric is set in a reaction vessel 3 and the vessel is exhausted and vacuumed. Then, the vapor 7 of a halide such as chlorides of Al, Mg, Ti and those alloys and reactive gas such as H2 or innert gas 8 such as Ar and He are introduced in the reaction vessel 3. Simultaneously, glow discharge is generated in the reaction vessel 3 through electrically conducting a high frequency coil 5 and the metal compound is isolated by the plasma to attach the metal to the fiber 6. The metal tightly adheres on the fiber 6 which is undamaged by the metal and the fiber reinforced metal excellent in strength at high temp. and in elasticity is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing fiber reinforced metal (hereinafter abbreviated as FRM). More particularly, the present invention relates to applying a matrix metal to a fiber bundle by plasma chemical vapor deposition (hereinafter abbreviated as plasma CVD).

The purpose of the present invention is to provide a high-temperature structural material that exhibits high strength, high elasticity, and toughness, and maintains its performance even at high temperatures, and is expected to be applied to engines, etc., and is also excellent as a conductive material and a sliding material. It is an object of the present invention to provide a method for manufacturing a fiber reinforced metal material having such characteristics.

Various processes have been proposed as methods for manufacturing fiber-reinforced metals. For example, methods include immersing fibers in a metal solution (infiltration method), sandwiching fibers with metal foil or metal plate and heating and pressurizing them to integrate them (sandinch method), and mixing fibers and metal powder. A method in which metal powder is melted with plasma or gas flame and then heated and pressurized to integrate it (powder metallurgy method), a method in which metal powder is melted with plasma or gas flame and then blown onto the fibers, and then heated and pressurized to integrate it (thermal spray method). A method in which fibers are wrapped in a metal film by electroplating, chemical plating, vacuum deposition, ion blating, sputtering, chemical vapor deposition, etc., and then heated and pressurized to integrate them (electroplating, chemical plating, vacuum deposition, ion・Brating,
Conventional methods such as sputtering and chemical vapor deposition are collectively referred to as the brating method. ) etc. have been proposed. However, it has not yet been possible to manufacture an FRM that exhibits sufficient performance. In order for the fibers to ideally reinforce the metal matrix, (1) the fibers must be uniformly mixed with the metal, (2) there must be sufficient adhesion between the fibers and the metal, and (3) the fibers must undergo chemical changes during the manufacturing process. It is necessary to prevent deterioration of its performance due to damage or mechanical damage.

However, in the methods proposed so far, the conditions (1) to (3) above are not fully satisfied.
A high-performance FRM has not yet been obtained. For example, in the infiltration method, active metals react with fibers, and inert metals do not wet the fibers, so they are not mixed uniformly and do not have good adhesion. In the sand inch method, powder metallurgy, and thermal spraying methods, it is difficult to arrange fibers uniformly in the metal, and the fibers are easily damaged when heated and pressurized. In the brating method, each fiber is coated with metal, then heated and pressed, and then integrated, so the fibers can be uniformly arranged in the metal.
This method can be said to be the most preferable because it causes less damage to the fibers during heating and pressing.

However, as described below, the brating method still has many drawbacks. First, in electroplating and chemical plating, it is difficult to apply aluminum and magnesium, which are typical base materials of FRM (because these metals are highly active, they react with water or oxygen during deposition and become oxides). ). Chemical vapor deposition requires high temperatures to thermally decompose metal 76 compounds, and as a result, fibers often deteriorate due to reactions between fibers and metals. Vacuum evaporation, sputtering, and ion blating are each 10-' to 10-"Pa, IF"
Since the metal is coated in a high vacuum around IO-"Pa, 10-", and -IPa, the mean free path of the metal vapor (atoms) is long, resulting in a large amount of metal adhering to one side of the fiber or fiber bundles. The inner fibers may not be coated. Therefore, in the FRM obtained by coating metal on fibers using this method and heating and pressurizing the fibers, the dispersion of the fibers into the metal is often partially non-uniform.

The present invention eliminates such drawbacks in FRM manufacturing, satisfies the conditions (1) to (3) above, and provides a method for manufacturing a high-performance FRM. That is, the present invention provides plasma CV
By D, a preform for I''RM suitable for obtaining a high-performance FRM is provided by decomposing a metal compound at a low temperature and depositing a base metal on the fiber.

In the present invention, fibers include monofilaments, tows, whiskers, etc. made of inorganic materials such as glass, boron, carbon, silicon carbide, silicon nitride, alumina, and boron carbide, or metals such as steel and tungsten. These include woven fabrics, non-woven fabrics, and paper.

In the present invention, light metals such as A1, Mg, Ti, Zn
, Sn, Pb and other low-melting point metals of the iron group (Fe, Ni, G
o) Heavy metals such as Cd, 'Mn, Cu, etc.

Noble metals such as Au, Ag, Pt, Ir, Os, Pd, Ta
, W, Nb, Mo, ■, high melting point metals such as Cr, Si, G
It is possible to use all kinds of metals such as semiconductor metals such as E and alloys thereof as the base material of the FRM. Especially A1. Mg
, Ti, and its alloys as base materials result in FRMs with excellent performance. These metals are deposited on the fiber surface by thermal decomposition reactions of organometallic compounds (alkyl metals, allyl metals, π-complexes, carbonyl metals, etc.) or inorganic metal compounds (halides, hydrides, etc.). In particular, chloride is preferred in terms of ease of handling, economy, and FRM performance.

Hereinafter, the present invention will be explained in detail with reference to FIG. Fibers 6 are placed in reaction tank 3, and this is evacuated. Next, a metal compound vapor 7 and a reactive gas 8 (or inert gas) are introduced into the reaction tank 3, and a high frequency is applied from the high frequency coil 5 to generate a glow discharge in the tank.

Plasma dissociates the metal compound and deposits the metal onto the fiber. The total gas partial pressure at the time of plasma generation is 1. -10'Pa
The pressure is preferably 10 to 103 Pa. As the reactive gas, II2 is usually used because it accelerates the decomposition of the metal compound, and as the inert gas, a rare gas such as He or Ar that does not react with the deposited metal is used.

The high-frequency electrode may be placed outside or inside the reaction tank, but it is more preferable to place it outside from the viewpoint of contamination of the electrode (or coil). The frequency of high frequency is also from number 1 K11z to number G11
Up to z, any frequency that is normally used as a high frequency may be used.

Heating the fibers is effective in increasing the metal deposition rate. A general heater is used to heat the fibers, but for conductive fibers such as carbon fibers and metal fibers, the temperature of the fibers can be raised by directly applying electricity to the fibers. In a transparent reaction tank, heating using infrared rays or laser is also possible. The metal deposition rate on the fiber is the total gas partial pressure above,
The partial pressure (flow rate) of each gas is governed by the high frequency input and temperature. If the deposition rate is too high, metal will be deposited only on the surface layer of the fiber bundle, and the fibers inside the fiber bundle will not be coated with metal. Therefore, the gas diffusion rate and the metal deposition rate on the fibers can be controlled to achieve the highest production efficiency.
It is necessary to coat the metal under conditions that allow for the most uniform coating, but the conditions vary depending on the individual metal compound.

Various reactions can be considered as reactions in plasma, and examples of reactions in which a metal compound precipitates as a metal are as follows.

・Organic metal R-M+RM→R-R+2M (R: alkyl group) (M: metal) 2R-M+H2→2RH+2M ・Inorganic compound M-X0M-X-)X2+2M (X: halogen) 2M-'X+l+ , → 2 HX + 2 M The metal-coated fiber thus obtained is a pre-preform for FRM in which the fibers, books, and books are uniformly coated with metal, so the fibers are laminated and heated and pressed. , when integrated, an F RM with excellent mechanical performance is obtained.

To obtain an alloy composition of 1'', R, M of the base material, two or more metals are deposited simultaneously, or one metal (or more than one metal) is deposited and then the other metal is deposited. Metals are precipitated and alloyed when integrated by heating and pressurizing.

Example 1゜11th Si1 device i? In 1, the average surface f￥: 12μII+, length 20C1 consisting of 500 lines is placed at the center of 1 reaction tank.
11 silicon carbide fibers (+-U) were arranged. After evacuating this reaction tank to 1 Pa, Ar gas was introduced, and 103
Pa. This reaction barrel Tsugai 41'h
Then, the fiber wetness was set to RO''C and 17.Next, a power of 13.5 MHz and 0.3 KW was applied to the high frequency electrode to generate plasma in the reaction tank.A1.
(CH3') 3 containing Ar gas (Al(CH3)3
Concentration 1, 33111g/cc) at 100cc/min
, H2 gas was introduced at 120 cc/min, the total gas pressure was maintained for 15 minutes under conditions of 1.5XIO'Pa, and plasma CVD was performed.

The obtained carbon fibers were each coated with an A1 film of about 3 μn+. This A1 coated carbon fiber is laminated to form a 10"
17RM was obtained by heating and pressurizing at 550° C. and 500 kg/c♂ for about 10 minutes under a vacuum of −1 Pa. This FRM is
Tensile strength 70 kg/+nn+ with fiber volume content 44%
2 tensile modulus of 11, OOOkg/nwn''.

Example 2.゛According to the method of Example 1, the average diameter is 7μn1.3.000
Carbon fiber (1-U) with a length of 20 cm was coated with aluminum so that the total gas pressure was 3
By introducing Cl3.5jC14,112 and Ar, about 30
Plasma CVD was performed for 1 minute.

As a result, an A1 alloy film with a thickness of about 2 μm and having a composition of 90% A1 and 5ilO% was formed on the surface of the carbon fiber. This A1
Alloy-coated carbon fibers were laminated, 10-”Pa, 450°C,
The FRM obtained by molding at 800 kg/cnt has a fiber volume content of 41% and a tensile strength of 105 kg/nun.
, tensile modulus of 14, and O'OOkg/nun2.

Example 3 According to the method of Example 1, a reaction tank containing 1 to 10 boron filaments each having a diameter of 100 μm was heated to a fiber temperature of 4.
00°C, 400Ktlz from the high frequency coil, 0.
While applying 5KW of power, the total gas pressure is 5. X102Pa,
(TiC14, +-12, Ar), plasma CVD
A 25 μm T1 film was applied to each filament.

This Ti coated boron filament is B/TiF
When made into RM, it showed a tensile strength of 130 kg/nun''.

Example 4゜Diameter o, i~0.5μm11, length 1~100μm11
0.1g of carbon fiber whisker aggregate was placed in a reaction tank, the fiber temperature was 300°C, the high frequency coil was 13.5MHz, 1
．． Under OKW conditions, the total gas pressure is 5 x 103 Pa (Al
Plasma CVD was performed using Cl3, Mg(CII3)3, H2, Ar).

As a result, whiskers 0, 1 g'tt L, 0.5
g of Al-Mg alloy (Mg4wt%) could be coated. This A1 alloy coated whisker has a tensile strength of 42
An isotropic F RM of kg/+mu2 could be obtained.

[Brief explanation of drawings]

FIG. 1 is a process diagram showing an embodiment according to the present invention. 1
is a vacuum pump, 2 is a vacuum gauge, 3 is a reaction tank, 4 is a heater, 5 is a high frequency electrode or coil, 6 is a fiber, 7 is a metal compound vapor generator, and 8 is a reactive or inert gas cylinder. Patent applicant Nikkiso Co., Ltd.

Claims (1)

[Claims] (1) A method for producing a fiber-reinforced metal, characterized in that a metal compound is decomposed in low-temperature plasma and a metal serving as a base material is applied onto the fibers. (2) The base metal is A1. The method for producing a fiber-reinforced metal according to claim 1, wherein the alloy is an alloy mainly containing either Mg or Ti. (3) The method for producing a fiber-reinforced metal according to claim 1, wherein the metal compound is a halide.