JPH04325471A - Production of ceramic composite body - Google Patents

Abstract

PURPOSE:To obtain a ceramic composite body with high productivity and to prevent crack and deformation even when a metallic material used is thick or is embedded in a ceramic molded body at high density. CONSTITUTION:A ceramic green molded body contg. a ceramic material and an org. binder is formed, a metallic material coated with a solid lubricant not reacting with the ceramic material is embedded in the molded body and this molded body is fired. Strain produced between the metallic and ceramic materials at the time of firing is relieved by the solid lubricant.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a ceramic composite body in which a metal material is embedded in a ceramic sintered body.

0002

BACKGROUND OF THE INVENTION The following techniques are known for manufacturing a composite body in which a metal material is embedded in a ceramic sintered body.

[0003] ■ A plurality of ceramic green sheets coated with carbon paste are laminated and fired to create a ceramic sintered body having a void layer, and molten metal is injected into the void layer of this ceramic sintered body. Method for manufacturing a laminated actuator (Japanese Patent Application Laid-Open No. 62-21197
Publication No. 5).

[0004] Ceramic green sheets printed with carbon paste and regular green sheets are alternately laminated and fired to create a porous ceramic sintered body having holes. A method of manufacturing a piezoelectric ceramic body by applying metal plating to the holes of the body to impart conductivity (Japanese Patent Laid-Open No. 62-277
Publication No. 780).

[0005] ■ A paste pattern made of conductive paste or an organic metal compound is formed on a ceramic green sheet using a screen printing method, and multiple sheets of this are laminated and simultaneously fired to create a ceramic composite containing a conductive metal material. Method for manufacturing the body (Japanese Patent Application Laid-Open No. 60-54865
(Japanese Patent Application Laid-Open No. 63-47137).

(2) A method of manufacturing a ceramic sintered body by embedding a general metal material other than a conductive paste in a ceramic green molded body and then firing it.

[0007]

[Problems to be Solved by the Invention] In the above methods (1) and (2), a ceramic sintered body having a void layer or holes inside is manufactured using carbon paste or the like, and then a metal material is applied to the void layer or holes. Because it is buried by means such as injection or plating, productivity is poor as it is not fired simultaneously. Also,
Since the coating thickness of carbon paste is at most about 20 μm, the thickness of the voids formed after firing shrinkage is also 15 μm.
It was limited to about μm.

[0008] Even in the method (2) above, since a screen printing method is used, the thickness of the conductive paste is about 10 μm at most.

Furthermore, in the method (2) above, ceramics generally undergo sintering shrinkage of 8 to 20%, whereas metal materials exhibit thermal expansion, albeit slightly. Therefore, both exhibit opposite behavior during firing, and cracks are likely to occur during firing when the thickness of the metal material is large or when the metal material is embedded in a ceramic molded body at a high density. Further, when the metal material is thin and incorporated in a low density, even if it can be sintered without cracking, the resulting sintered body has a drawback that it has large residual strain and is accompanied by deformation.

[0010] The present invention solves the above-mentioned conventional drawbacks, and aims to improve productivity, and also to improve productivity when the thickness of the metal material is large or when the metal material is placed inside a ceramic molded body at high density. An object of the present invention is to provide a method for manufacturing a ceramic composite that does not cause cracks during firing even when buried in a ceramic composite body.

[0011]

[Means for Solving the Problems] The method for producing a ceramic composite of the present invention includes coating a ceramic green molded body containing a ceramic material and an organic binder with a solid lubricant that does not react with the ceramic material. The above object is achieved by embedding the metal material and then firing it.

The ceramic green molded body used in the present invention is formed from a composition containing a ceramic material and an organic bond. If necessary, add an organic solvent such as ethyl alcohol, isopropyl alcohol, methyl ethyl ketone, or toluene, and knead with a kneader such as a ball mill or vibration mill.The resulting solution is then cast using a doctor blade.
It is formed by a molding method such as injection molding, extrusion molding, or compression molding.

[0013] Examples of the above ceramic materials include:
Alumina, zirconia, magnesia, sialon, spinel, mullite, crystallized glass, silicon carbide, silicon nitride,
Powders such as aluminum nitride and MgO-SiO2-C
aO system, B2O3-SiO2 system, PbO-B2O3-S
iO2 system, CaO-SiO2-MgO-B2O3 system, P
Examples include bO-SiO2-B2O3-CaO-based glass frit powders, which may be used alone or in combination of two or more.

[0014] Examples of the organic binder include polymeric materials such as polyvinyl butyral, polyvinyl alcohol, polymethyl methacrylate, polybutyl methacrylate, cellulose, dextrin, polyethylene wax, starch, and casein, used alone or in combination of two or more. Used together. Furthermore, a plasticizer such as dioctyl phthalate, dibutyl phthalate, polyethylene glycol, etc. may be added as necessary.

[0015] Examples of metal materials include metals such as gold, silver, titanium, chromium, copper, nickel, iron, molybdenum, manganese, aluminum, platinum, tungsten, iridium, rhodium, cobalt, vanadium, etc., and metals such as these metals. A linear body, foil, or plate-shaped body made of an alloy is used. In addition, if a predetermined shape is required, it can be created by punching, etching, or laser processing a foil or plate-shaped body.

[0016] Examples of the solid lubricant coating the metal material include boron nitride, molybdenum disilicide, molybdenum disulfide, tungsten disulfide, lead oxide, lead disulfide, calcium fluoride, mica, etc. It is sufficient to appropriately adopt a material that is used in combination with more than one type and does not react with the above ceramic material during firing, and it is particularly preferable to use a material that does not sinter during firing.

For example, alumina-PbO-B2O3-S
When using an iO2-CaO system as a ceramic material, boron nitride may be used as a solid lubricant to coat the metal. These solid lubricants typically include methanol, ethanol, butanol, propanol, cyclohexanol, terpineol, methyl ethyl ketone, acetone, ethyl acetate, toluene, xylene, benzene,
It is used as a solution or paste dispersed in a solvent such as ether, hexane, carbon tetrachloride, or water. In addition, when coating a metal material with only these solid lubricants, if the coating strength of the solid lubricant is low and it peels off from the metal material, if necessary, add the above-mentioned organic binder to a solution containing the solid lubricant. It may be added to increase the coating strength of the solid lubricant.

The amount of organic binder is not particularly limited, but is generally 0.5 to 10% by weight based on the solid lubricant.
Just add it.

In the present invention, the method for coating the metal material with the solid lubricant is not particularly limited, but examples include a method in which the metal material is immersed in a solution or paste in which the solid lubricant is dispersed, pulled up, and then dried; A method of spraying a solid lubricant onto the material and then drying the material may be adopted as appropriate. Note that, if necessary, the above operation may be repeated multiple times to form a layer of solid lubricant having a desired thickness.

The method for embedding the metal material in the ceramic green molded body is not particularly limited and any conventionally known method can be used. A method of sandwiching this metal material between ceramic green sheets and bonding with heat, a method of placing this metal material in a composition and press-molding it, a method of holding this metal material in a mold such as a plaster mold and A casting method or the like in which the composition is poured into the surrounding area is appropriately employed.

[0021] Next, the composite molded body in which the metal material is embedded in this manner is supplied to a heating furnace and fired, thereby obtaining a ceramic composite body containing the metal material.

The sintering conditions are appropriately determined in consideration of the type of ceramic material used, but are generally 1 to 10
The temperature is raised to 600 to 1850°C at a heating rate of 0°C/Hr, and the temperature is maintained for 1 to 5 hours for firing. Further, in this step, if the metal material and the solid lubricant are oxidized, it is preferable to carry out the step in a reducing atmosphere.

[0023] During this firing, the ceramic material generally exhibits a linear shrinkage rate of 8 to 20%. Therefore, if the metal material is not coated with a solid lubricant, a large strain will occur between the ceramic material and the non-shrinking metal material, resulting in cracks in the sintered body or large deformation. becomes.

In the present invention, since a lubricating layer made of a solid lubricant is provided between the ceramic material and the metal material, when the ceramic material shrinks due to sintering, the lubricating layer causes a slipping phenomenon. By causing this, strain stress between the metal material and the metal material can be alleviated. Therefore,
The sintered body does not crack or deform, and a ceramic composite containing a metal material can be obtained.

[0025]

[Operation] The surface of the metal material is coated with a solid lubricant that does not react with the ceramic material, and is fired in this state, so the solid lubricant will not cause slipping during sintering shrinkage due to firing. This relieves strain stress between the metal material and the molded body. Therefore, unlike when the solid lubricant is not coated, the part of the sintered body that is in contact with the metal material does not apply excessive pressure on the metal material, and the strain stress between the ceramic material and the metal material is significantly reduced. deformation will also be eliminated.

[0026]

EXAMPLES Examples of the method for manufacturing a ceramic composite of the present invention will be described below. Note that "parts" means "parts by weight."

Example 1 40 parts of alumina powder with an average particle size of 3 μm, average particle size of 5 μm
60 parts of PbO-SiO2-B2O3-CaO glass frit (deflection point 684°C), 12 parts of polyvinyl butyral, 4.5 parts of dioctyl phthalate, 24 parts of methyl ethyl ketone, 18 parts of toluene, and 18 parts of isopropyl alcohol were fed to an alumina ball mill. After kneading for 24 hours, the resulting solution was applied onto a polyethylene terephthalate film and dried to produce a ceramic green sheet with a thickness of 200 μm.

On the other hand, colloidal boron nitride with an average particle size of 1 μm was supplied to an alumina ball mill, and further, to the alumina ball mill, 30 parts of benzene, 15 parts of ethanol, 15 parts of terpineol, and polymethyl methacrylate were added to 100 parts of colloidal boron nitride. (Mw: 80,000) was added and kneaded for 48 hours, and the viscosity was increased to 2,600 cps while the solvent was scattered at 40° C. to obtain a coating liquid.

Next, a gold wire having a length of 50 mm and a diameter of 100 μm was immersed in the above coating liquid, and was pulled up and dried to form a boron nitride coating having a total thickness of 12 μm around the gold wire.

[0030] Next, the above green sheet is 50×50
x 0.2 mm, stacked 10 of these, and placed 10 coated gold wires in parallel at 2 mm intervals,
10 green sheets were laminated on top of it, this laminate was held at 160°C for 2 hours, and crimped with a pressure of 250 kg/cm2 to form a ceramic green molded body (50 x 50 x 4 mm) with a built-in coated gold wire. ) was obtained.

This ceramic green molded body was supplied to a heating furnace, heated to 500°C at a heating rate of 5°C/hr, held for 2 hours to degrease, and further heated at 50°C/hr for 8
The temperature was raised to 50° C. and held for 2 hours for firing to obtain a ceramic composite containing gold wires.

[0032] This ceramic composite did not undergo any deformation, and the thickness of the ceramic composite was 2 m parallel to the surface where the end of the gold wire was exposed.
When it was cut into lengths of m, the gold wire inside was retained without falling off.

Example 2 40 parts of alumina powder with an average particle size of 3 μm, average particle size of 5 μm
m PbO-SiO2-B2O3 glass frit (
yield point 479°C) 60 parts, polymethyl methacrylate (
A ceramic green sheet with a thickness of 200 μm was prepared in the same manner as in Example 1, except that 17 parts of Mw: 130,000), 5 parts of dibutyl phthalate, 24 parts of methyl ethyl ketone, 18 parts of toluene, and 18 parts of isopropyl alcohol were fed to the ball mill. did.

Next, molybdenum disulfide having an average particle size of 2 μm was supplied to an alumina ball mill, and 3 parts of benzene was added to 100 parts of molybdenum disulfide to the alumina ball mill.
0 parts, 15 parts of ethanol, 15 parts of terpineol,
A coating solution was obtained in the same manner as in Example 1, except that 1 part of polymethyl methacrylate (Mw: 80,000) was added to each sample.

[0035] Next, the length is 50 mm and the diameter is 100 μm.
A tungsten wire was immersed in the above-mentioned coating liquid, and then pulled up and dried to form a molybdenum disulfide coating having a total thickness of 12 μm around the tungsten wire.

Hereinafter, in the same manner as in Example 1, a ceramic green molded body (50
x50 x 4 mm) was obtained.

[0037] This ceramic green molded body was fed into a heating furnace, heated to 350°C at a heating rate of 5°C/hr, held for 2 hours to degrease, and then fed into a nitrogen stream of 5kg/cm2. , 680℃ at a heating rate of 10℃/hr
The temperature was raised to 100°C and held for 2 hours to obtain a ceramic composite with a built-in tungsten wire.

This ceramic composite did not undergo any deformation, and when cut to a thickness of 2 mm parallel to the surface where the end of the tungsten wire was exposed, the tungsten wire was held without falling off.

[0039]

[Effects of the Invention] According to the method for manufacturing a ceramic composite of the present invention, productivity is improved because the metal material coated with a solid lubricant is buried in the ceramic green molded body and fired. Furthermore, it is possible to obtain a ceramic composite which is not limited by the thickness or size of the metal material. Moreover, even if the buried metal material is large in size or buried at high density, the solid lubricant can alleviate the strain between the metal material and ceramic material during firing, preventing cracks. It does not develop or deform.

Claims (1)

[Claims] Claim 1: A metal material coated with a solid lubricant that does not react with the ceramic material is buried in a ceramic green molded body containing a ceramic material and an organic binder, and then fired. Method for manufacturing ceramic composites.