JP2002284590A - Ceramics-metal composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramics-metal composite material that can control a thermal expansion coefficient corresponding to the thermal expansion coefficient of a bonding mate material, has large stiffness and excels in heat resistance. SOLUTION: The ceramics-metal composite material is characterized in that a matrix comprises a Si alloy containing Si of 90 atomic % or more and a reinforced material comprises Al2 O3 , and a SiC powder or fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic-metal composite material used in the fields of electricity, communications, machinery, precision instruments, and automobiles.

[0002]

2. Description of the Related Art Al alloys have been used in various fields in recent years because they are lightweight, excellent in corrosion resistance, and excellent in thermal conductivity and electrical conductivity. Particularly in the field of ceramics, ceramic-metal composite materials in which an Al alloy is used as a matrix and a ceramic is used as a reinforcing material to combine the two with the use of the above characteristics of the Al alloy have come to be used because of their light weight. . In particular, a composite material produced by melting and impregnating an Al alloy in a preform is expected to be demanded in a wide range of fields because it is advantageous for producing a complicated shape. In addition, in order to apply and expand the metal-ceramic composite material to various uses, it is often necessary to join the same or different materials.

However, when there is a large difference in the coefficient of thermal expansion between the two materials to be joined, internal stress and strain are likely to occur. Therefore, there is a problem that joining with various materials is difficult. In particular,
Aluminum nitride (AlN) has excellent performance as an insulating material with good thermal conductivity, but has a small coefficient of thermal expansion of 5 × 10 ⁻⁶ / ° C. (room temperature), so a ceramic-metal composite material using an Al alloy as a matrix When a conductive material is manufactured by bonding to the above, the above-described problem becomes apparent. In addition, since the composite material contains Al, the rigidity of the member is not sufficient, and the heat resistance is as low as about 300 ° C., which leaves a problem.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a ceramic-metal composite material which can control the coefficient of thermal expansion in accordance with the coefficient of thermal expansion of the material to be joined, and has high rigidity and excellent heat resistance. The purpose is to provide.

[0005]

Means for Solving the Problems The present invention has been made as a result of intensive studies to solve the above-mentioned problems. As a result, SiC and Al ₂ O ₃
Found that a ceramic-metal composite material obtained by infiltrating a Si alloy into a preform made of a powder or a fiber can control the thermal expansion coefficient over a wide range and has both high rigidity and heat resistance, and completed the present invention. did.

That is, the present invention provides a composite material characterized by the following constitution. (1) Si whose matrix contains 90 atomic% or more of Si
An alloy, a ceramic reinforcing material is characterized in that it consists of Al ₂ O ₃ and SiC powder or fiber - metal composite material (claim 1). (2) a Al ₂ O ₃ and SiC powder or fiber packing ratio 40 to 80% by volume, and filling rate of SiC 3
2. The ceramic-metal composite material according to claim 1, wherein the content is not less than 80% by volume. (3) 250 GPa by controlling the filling ratio of powder or fiber of Al ₂ O ₃ and SiC and the filling ratio of SiC.
The above Young's modulus and 2.8 × 10 ^{−6 /} ° C. to 6.5 × 10 ⁻⁶
The ceramic-metal composite material according to claim 1 or 2, wherein the ceramic-metal composite material has a thermal expansion coefficient of / ° C.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The matrix of the ceramic-metal composite material of the present invention is preferably a Si alloy containing 90 atomic% or more of Si.
Si has the effect of increasing the rigidity of the composite material, and if the content of Si is less than 90 atomic%, the Young's modulus of the composite material may decrease. The remainder of the Si alloy other than Si is preferably Al because of its light weight and excellent corrosion resistance.

The reinforcing material for the ceramic-metal composite material of the present invention is preferably powder or fiber of Al ₂ O ₃ and SiC. Al ₂ O ₃ and SiC are both necessary for adjusting the Young's modulus and the coefficient of thermal expansion of the ceramic-metal composite material. Adjustment of characteristics becomes possible. The form of use of Al ₂ O ₃ or SiC can be either powder or fiber.

In the ceramic-metal composite material of the present invention, the filling ratio of Al ₂ O ₃ and SiC powder or fiber is 40 to 80% by volume, and the filling ratio of SiC is 3% by volume or more and less than 80% by volume. preferable. Al ₂ O ₃ and S
If the filling ratio of the iC powder or fiber is less than 40% by volume, the strength of the preform is insufficient, and if it is more than 80% by volume, it becomes difficult to produce the preform. If the filling rate of SiC is less than 3% by volume, the preform is hardly impregnated with the Si alloy, and pores are easily generated.

By controlling the filling ratio of Al ₂ O ₃ and SiC powder or fiber and the filling ratio of SiC to the following specific ranges, the Young's modulus is 250 GPa or more and the thermal expansion coefficient is 2.8 × 10 ^-6. / ° C to 6.5 × 10 ^-6 / ° C. Specifically, the mixing ratio and the filling rate of powder or fibers of Al ₂ O ₃ and SiC is, Al ₂ O ₃ and SiC powder or fiber total packing ratio of of a 40 to 80% by volume,
Further, the filling rate of SiC is preferably 3% by volume or more and less than 80% by volume.

As a method for producing a preform, a conventional method is used.
Can be used. For example, Al _TwoO_ThreePowder or fiber
Mix the required amount of SiC particles or fibers with
And C as an impregnating aid or organic bar
Add and mix the inders. Next, this mixture is used in a molding die.
After filling and pressing, the binder is
It is cured to produce a preform. In addition, preform
Al inside_TwoO_ThreeOf SiC and SiC powder or fiber
Is adjusted by selecting an appropriate particle size distribution.

The preform prepared in this manner has S
The i-alloy is brought into contact, heated and melted in a non-oxidizing atmosphere to a temperature equal to or higher than the melting point of the Si alloy (for example, 1500 ° C. or higher), and the preform is impregnated with the Si alloy to obtain a ceramic-metal composite material. This composite material can be machined as required to be processed into an arbitrary shape.

[0013]

The present invention will be described below with reference to examples.

Preparation and Evaluation of Test Specimens SiC powder (average particle size: 14 μm, manufactured by Shinano Electric Refining Co.) and Al ₂ O ₃ powder (average particle size: 14 μm, manufactured by Pacific Ocean Random Co., Ltd.) Mixture 1)
After adding 10 parts by weight (3 parts by weight in terms of carbon) of a phenol resin as an organic binder to 00 parts by weight and pressing,
The preform was obtained by heating in vacuum at 500 ° C. for 3 hours.
With the obtained preform and the Si alloy in contact with each other,
The preform was heated at 1600 ° C. for 3 hours in Ar to impregnate the melt of the Si alloy to produce a ceramic-metal composite material. Next, the composite material was cut into 3 × 4
A test piece having a size of × 40 mm was prepared, the presence or absence of impregnation failure was visually observed, and the Young's modulus and the coefficient of thermal expansion were measured. Table 1 shows the results.

[0015]

[Table 1]

In Examples 1 to 3, SiC and Al ₂ O ₃
And the content of Si in the Si alloy were within the ranges shown in the claims, and both the Young's modulus and the coefficient of thermal expansion showed good values. On the other hand, in Comparative Examples 1 and 2, there were many pores in the test piece, and the Young's modulus and the coefficient of thermal expansion varied greatly depending on the part of the test piece. Did not.

[0017]

According to the present invention, it is possible to provide a ceramic-metal composite material which can control the coefficient of thermal expansion in accordance with the coefficient of thermal expansion of the material to be joined, and has high rigidity and excellent heat resistance. it can.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court (Reference) (C22C 49/02 101: 14) (72) Inventor Ichiro Aoki 2-4-2 Daisaku, Sakura City, Chiba Prefecture Pacific 4K020 AA06 AA08 AA22 AC07 BA05 BB02 BB22

Claims (3)

[Claims] The matrix is made of a Si alloy containing 90 atomic% or more of Si, and the reinforcing material is Al ₂ O ₃ and SiC.
A ceramic-metal composite material comprising a powder or a fiber of the above. 2. The method according to claim 1, wherein the filling rate of Al ₂ O ₃ and SiC powder or fiber is 40 to 80% by volume, and the filling rate of SiC is 3% by volume or more and less than 80% by volume. Item 2. The ceramic-metal composite material according to Item 1. 3. By controlling the filling rate of powder or fiber of Al ₂ O ₃ and SiC and the filling rate of SiC, 25
Young's modulus of 0 GPa or more and 2.8 × 10 ^{−6 /} ° C. to 6.5
The ceramic-metal composite material according to claim 1, having a coefficient of thermal expansion of × 10 ⁻⁶ / ° C. 4.