JPH042668A - Production of ceramic composite - Google Patents

Abstract

PURPOSE:To reduce strain stress between ceramics and a metal by incorporating a metal material covered with a specific covering material into a ceramic green formed article and burning. CONSTITUTION:A metallic material 1 is covered with a covering material 2 consisting of an organic material or carbon powder so as to become to thickness d1 and d2 corresponding to sintering shrinkage of a ceramic green formed article 3. Then the metal material 1 is embedded into a ceramic green formed article 3 and the ceramic composite green formed article 3 is heated to 280-600 deg.C at a temperature raising rate of 1-100 deg.C/hr and degreased for 1-5hr and space 5 is formed between a ceramic degreasing body 4 and metal material 1 and then the degreased ceramic composite green formed article is heated to 600-1850 deg.C at a raising rate of 10-200 deg.C/hr and burned for 1-5hr.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] 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.

[Conventional technology]

Regarding the manufacturing method of a composite body in which a metal material is embedded in a ceramic sintered body, various techniques such as those described below are known.

(11 Method of manufacturing a laminated actuator by injecting molten metal into the void layer of a ceramic sintered body including a void layer obtained by laminating and firing ceramic green sheets coated with carbon paste 211975
Publication No.).

(2) Ceramic green sheets printed with carbon paste and regular green sheets are alternately laminated and fired, and the pores of the porous ceramic sintered body are plated with metal to give conductivity. A method of manufacturing a piezoelectric ceramic body (Japanese Patent Application Laid-Open No. 62-277780).

(3) A method of manufacturing a ceramic composite containing a conductive metal material by forming a paste pattern made of a conductive paste or an organometallic compound on a ceramic green using a screen printing method, and then laminating and co-firing the patterns. (JP-A-60-54865, JP-A-63-4
Publication No. 7137).

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

[Problem to be solved by the invention]

In methods (1) and (2) above, a ceramic sintered body having a void layer or porous portion inside is manufactured using carbon paste or the like, and then a metal material is injected into the void layer or porous portion. Because it is buried by plating or other means, it is not fired at the same time, and the thickness of the carbon paste applied is at most about 20 μm, and the thickness of the voids formed after shrinkage during firing and the thickness of the metal material to be buried are also up to about 15 μm. was limited to.

Furthermore, even in the method (3) above, the thickness of the conductive paste was about 10 μm at most since the screen printing method was used.

Furthermore, in the method (4) above, ceramics generally have 8
Sintering shrinkage of ~20% occurs, whereas metallic materials are slightly thermally expandable. Therefore, the two exhibit opposite behavior during firing, and when the thickness of the metal material is large or when the metal material is embedded in a ceramic molded body at high density, cracking occurs during firing.

ri easily occurs. Further, in the case where the metal material is thin and contained in a low density, even if sintering can be performed without producing a crank, the sintered body has a large residual strain and is accompanied by deformation.

[Means to solve the problem]

The method for manufacturing a ceramic composite of the present invention is aimed at solving the above-mentioned problems, and in manufacturing the ceramic composite by incorporating a metal material into a ceramic green molded body and firing it, The contact portion of the metal material with the ceramic green molded body is coated with a coating material made of an organic material or carbon powder to a thickness corresponding to the sintering shrinkage of the ceramic green molded body, and the coated metal material is used as the ceramic green molded body. It is characterized in that it is incorporated into a container and then fired.

In the method of this invention, the ceramic material is not particularly limited, and may include powders such as alumina, zirconia, magnesia, sialon, spinel, mullite, crystallized glass, silicon carbide, silicon nitride, aluminum nitride, boron nitride, and MgO. -3i02-CaO system, B2
0)-SiOx system, PbO-B2O3-5i02 system, C
aO-5i02CaO-5i02- system, PbO-5iO
, -BzO, -CaO type glass frit powders can be used alone or in combination of two or more types. Further, if necessary, organic binders, plasticizers, solvents, etc. are added to these ceramic powders, and after kneading them in a mixer such as a ball mill, a ceramic green molded body is produced by various molding methods.

Examples of metal materials include gold, silver, titanium, chromium,
Linear bodies, foils, and plate bodies made of metals such as copper, nickel, iron, molybdenum, manganese, aluminum, platinum, tungsten, iridium, rhodium, cobalt, vanadium, and alloys of these metals are used. Moreover, if a predetermined shape is required, it can be created by punching or etching a foil or plate-shaped body.

Examples of organic materials or carbon powders used as coating materials are as follows.

(1) Polyvinyl butyral, polyvinyl alcohol, poly(meth)acrylate, cellulose, dextrin, polyethylene wax, starch, casein, paraffin wax, microtalin wax, polymethylstyrene, polyurethane, unsaturated polyester, phenolic resin, epoxy resin, photosensitive Polymer materials such as synthetic resins.

(2) Naphthalene, benzoic acid, anthraquinone, anthranilic acid, isophthalonitrile, 2,3-dichloro-1
, 4-naphthoquinone, α-naphthol, p-nitrophenyl, etc.

(3) Carbon powder such as graphite, carbon black, glassy carbon, etc.

These materials include methanol, ethanol, butanol, propatool, cyclohexanol,
A coating liquid is prepared by dissolving or dispersing it in a solvent such as terpineol, methyl ethyl ketone, acetone, ethyl acetate, toluene, xylene, benzene, ether, hexane, carbon tetrachloride, or water.

In this invention, the method of coating the metal material with the coating material is not particularly limited, but examples include a method of immersing the metal material in a solution containing an organic material or carbon paste, pulling it up and drying it, a solution of the organic material, etc. This method involves spraying it on and then drying it. In addition, if necessary,
The above operation may be repeated multiple times to obtain the desired thickness.

Furthermore, the method of embedding the coated metal material in the ceramic green molded body is not particularly limited. The metal material is placed in a mold such as a plaster mold, and the ceramic is poured around it, which is a casting method, as appropriate.

Next, the method of this invention will be explained with reference to the drawings.

1 to 3 are cross-sectional views illustrating the method of the present invention in the order of its steps. FIG. 1 shows a state in which a metal material is incorporated in a ceramic green molded body before sintering, and FIG.
The state after the degreasing process is shown, and FIG. 3 shows the ceramic composite obtained by firing.

In FIG. 1, 1 is a linear metal material, and a covering material 2 is coated around it. 3 is a ceramic green molded body. For this coating method, method for incorporating the linear metal material, etc., the above-mentioned methods are appropriately adopted.

Further, the coating material 2 is appropriately selected from the above-mentioned materials, and the coating thickness is set to correspond to the sintering shrinkage of the ceramic green molded body 3.

That is, if the diameter of the linear metal material 1 is r and the sintering wire shrinkage rate of the ceramic green molded body 3 is X%, then the firing shrinkage between the walls of the ceramic green molded body in the area occupied by the coated metal material 2 and the coating thickness are The relationship between d3 and d2 is as shown in the following equation.

(dl +dz) = [(r +d+ +dz) X
(x/100)] Therefore, r=80. us, x=
If it is 20%, the thickness of coating material 2 (dt+dz) is 2
It is 0 μm.

It is desirable to make this coating thickness as uniform as possible.
The thickness of the coating around the linear metal material 1 is uniformly 10μ.
m. ~ The ceramic green molded body 3 containing the metal material 1 in the state shown in FIG.
The temperature is raised to ~600°C and held for 1 to 5 hours to degrease. In this degreasing step, the coating material 2 decomposes and scatters and disappears, and a gap 5 is formed between the ceramic degreased body 4 and the metal material 1 (FIG. 2).

Note that this degreasing step may be performed under reduced pressure, or if the metal material 1 is oxidized, it is preferable to degrease it in a reducing atmosphere such as nitrogen or argon.

Next, by firing, a ceramic composite containing a metal material is obtained (FIG. 3).

The firing conditions are appropriately determined in consideration of the type of ceramic powder, but the temperature is raised to 600 to 1850°C at a heating rate of 10 to 150°C, and the temperature is
It is common to hold for ~5 hours.

Note that even if the firing condition is a temperature higher than the melting point of the metal material 2, it is possible because the molten metal material 1 will solidify upon cooling. However, since the melt of the metal material 1 and its vapor may diffuse into the ceramic during sintering, it is preferable to perform the firing at a temperature lower than the melting point of the metal material 1.

In this firing step as well, if oxidation of the metal material 1 progresses, it is preferable to perform the firing in a reducing atmosphere as in the case of the degreasing step.

By the way, as is clear from the above, the void 5 shown in FIG. 2 has a size corresponding to the sintering shrinkage of the ceramic degreased body 4 (ceramic green molded body 3). Accordingly, the void 5 disappears,
As a result, as shown in FIG. 3, a ceramic composite body in which the metal material 1 and the ceramic sintered body 6 are closely integrated is obtained.

By the way, regarding the coating thickness of the coating material 2, the thickness (dl) corresponding to the sintering shrinkage of the ceramic green molded body 3
+dz> is (d++dt) = ((r+d++-at) x (x
/100)], the surface condition of the void portion 5 is at least as uneven as the diameter of the primary particle of the ceramic powder, and the metal material 1 is maintained in this uneven surface condition even after sintering shrinkage. It turns out. Therefore, coating material 2
The coating thickness has a tolerance corresponding to the primary particle diameter of the ceramic powder used, taking into account the above-mentioned uneven surface condition and the deformation of the metal material 1 during the sintering shrinkage process.

For example, the primary particle size of the ceramic powder used is 5 μm.
In the case of a ring, the linear metal material 1 will be held on a ceramic wall surface with unevenness of 5 μm. Therefore, similarly to the above, the sintering wire shrinkage of the ceramic green molded body 3 is 20
%, if the diameter of the linear metal material 1 is 80 μm, the coating thickness d (=d) of the coating material should be in the range of 10 μm±5 μm.

[Effect]

As described above, the method for producing a ceramic composite of the present invention involves coating a metal material with a coating material made of an organic material or carbon powder to a thickness corresponding to the sintering shrinkage of the ceramic green molded body to form a ceramic green body. Because it is built into the body, the coating material decomposes and scatters during the degreasing process, creating voids around the metal material, but the voids disappear due to sintering shrinkage during firing, and the ceramic wall retains the metal material. , the two are integrated. Therefore, unlike when no coating material is used, the ceramic wall does not press the metal material excessively during sintering shrinkage, the strain stress between the ceramic and the metal is significantly reduced, and deformation after firing is eliminated.

〔Example〕

Examples of the method for manufacturing a ceramic composite of the present invention will be described below.

Note that parts refer to parts by weight.

(Example 1) The following ceramic composition was mixed in an alumina ball mill.
The mixture was coated on a polyethylene terephthalate film and dried for 24 hours to produce a ceramic green sheet with a thickness of 100 μm.

Alumina powder (average particle size 3 μm) 40 parts Pb
O-5iOz-BzOs-CaO glass frift powder (average particle size 5 μm, yield point 684°C) 60 parts polyvinyl butyral 12 parts dioctyl phthalate 4.5 parts methyl ethyl ketone 24 parts toluene
18 parts isopropyl alcohol
18 parts This green sheet was heated at a rate of 25° C./hr, held at 850° C. for 2 hours, cooled, and its linear expansion coefficient was measured and found to be 13.0%.

A photosensitive resin liquid was obtained by uniformly dissolving the following composition as a coating material liquid.

Methyl methacrylate-methacrylic Mn-butyl-acrylic acid copolymer (6:2:2, Mw=150,000)
60 parts 2.2-bis(4-methacryloxyjethoxyphenyl)propane 15 parts hexamethylene diacrylate 15 parts 2.4-dimethylthioxanthone 2 parts ethyl p-dimethylaminobenzoate 2 parts malachite green
0.005 parts paramethoxyphenol
0.1 part methyl ethyl ketone 16
0 parts Next, a gold wire with a diameter of 100 μm is immersed in the photosensitive resin solution, pulled up and dried to form a photosensitive resin film around the gold wire, and this resin film is placed at a distance of 50 cm from a 3kW high-pressure mercury lamp. The film was cured by irradiating it with ultraviolet light at 25 mJ/cat. This process was repeated twice to form a photosensitive resin film with a thickness of 7.5 μm around the gold wire.

The above green sheet was cut into 50 x 50 x 0.1 m weights, 20 of these were laminated, 10 gold wires coated with the photosensitive resin were placed at intervals of 21 nm, and 20 green sheets were laminated on top of that. This was held at 160°C for 2 hours and crimped at a pressure of 250 kg/cJ to form a ceramic green molded body (50 x 50
X4 mm) was obtained.

This ceramic green molded body is supplied to a heating furnace, and
After degreasing by raising the temperature to 500°C at a heating rate of 50°C/hr and holding it for 2 hours, it is fired by increasing the temperature to 850°C at a rate of 50°C/hr and holding it for 2 hours, and the gold wire is built in. A ceramic composite was obtained.

This ceramic composite was not deformed, and even when it was cut to a thickness of 2111 mm parallel to the surface where the ends of the gold wires were exposed, the gold wires were retained without falling off.

(Example 2) PbO-5iO□-820 as glass lift powder
A ceramic green sheet with a thickness of 100 μm was prepared in the same manner as in Example 1, except that a ceramic green sheet having a ceramic green sheet having an average particle size of 5 μm and a yield point of 479° C. was used.

This green sheet was heated to 640°C at a rate of 25°C/hr.
After being held for 2 hours, it was cooled and the coefficient of linear expansion was measured and found to be 11.6%.

Next, using the same photosensitive resin liquid as in Example 1, a photosensitive resin film having a thickness of 6.5 μm was formed around the aluminum wire by the same process.

Using the above-mentioned green sheet and the above-mentioned coated aluminum wire, a 7-ramix gerene molded body (50 x 50 x 4 m) with a built-in coated aluminum wire was prepared in the same manner as in Example 1.
I got it.

This ceramic green molded body is supplied to a heating furnace, and
The temperature was raised to 500°C at a rate of 50°C/hr and held for 2 hours to degrease it, and then the temperature was further raised to 640°C at a rate of 50°C/hr and held for 2 hours to sinter the aluminum wire. A ceramic composite was obtained.

This ceramic composite was not deformed and the aluminum wire was held without falling off even when it was cut into a thickness of 2 mm parallel to the surface where the end of the aluminum wire was exposed.

(Example 3) Carbon paste (S
The carbon paste was mixed with 20 parts of terpineol, and the viscosity was increased to 2200 ps by scattering the solvent at 40°C. A carbon coating layer with a thickness of 7.5 μm was formed around the gold wire.

Example 1 This carbon-coated gold wire was prepared in the same manner as in Example 1.
A ceramic green molded body (50 x 50 x 4 cranes) was obtained by incorporating it into the same green sheet.

This ceramic green molded body is supplied to a heating furnace, and
The temperature was raised to 650°C at a heating rate of °C/hr, held for 24 hours, and then heated to 850°C at a rate of 50°C/hr and held for 2 hours to produce ceramics with built-in gold wires. Obtained a complex.

This ceramic composite was not deformed, and even when it was cut to a thickness of 2R parallel to the surface where the end of the gold wire was exposed, the gold wire was retained without falling off, as in Examples 1 and 2. .

(Comparative example) When sintering was carried out in the same manner as in Example 2 except that an uncoated 100 μm aluminum wire was used, the sintered body was found to have a crank and a large deformation on the surface where the aluminum wire was buried. However, the desired ceramic composite could not be obtained.

〔Effect of the invention〕

As described above, the method for producing a ceramic composite of the present invention involves coating a metal material with a coating material made of an organic material or carbon powder to a thickness corresponding to the sintering shrinkage of the ceramic green molded body. Since it is built into the molded body, the coating material decomposes and scatters during the degreasing process, creating voids around the metal material.
Since sintering shrinkage occurs during firing, the ceramic wall does not press the metal material excessively, the strain stress between the ceramic and the metal is significantly reduced, and a ceramic composite that does not deform after firing can be manufactured.

[Brief explanation of the drawing]

The drawings illustrate an example of the method of the present invention in the order of its steps, and FIG. 1 is a cross-sectional view of a state in which a metal material is incorporated in a ceramic green molded body, and FIG.
A cross-sectional view before firing, and FIG. 3 is a cross-sectional view showing a ceramic composite obtained by firing. 1--linear metal material, 2--coating material, 3--ceramic green molded body, 6--ceramic sintered body.

Claims (1)

[Claims] (1) When manufacturing a ceramic composite by incorporating a metal material into a ceramic green molded body and firing it, the contact surface of the metal material with the ceramic green molded body is designed to accommodate sintering shrinkage of the ceramic green molded body. 1. A method for manufacturing a ceramic composite, which comprises coating a ceramic green molded body with a coating material made of an organic material or carbon powder to a thickness of about 100 mL, incorporating the coated metal material into a ceramic green molded body, and then firing it.