JPS60127105A - Manufacture of ceramics part - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to an effective method for manufacturing Reramix parts of complex shapes, particularly thin walls or thin films.

(b) Technical background Reramix is harder than metals, plastics, etc., and has superior heat resistance, wear resistance, chemical stability, and high-temperature strength, so it is used as a heat-resistant structural material for engine parts, etc. , applications in electronic components, catalyst carriers, and wear-resistant materials are attracting attention.

However, ceramics are usually 1000 to 2200
Because it is manufactured at a high temperature of °C and is an extremely hard material, it is difficult to machine, making it difficult to manufacture parts with complex shapes, thin walls, or thin films for the various purposes mentioned above. has been done.

For example, the method of molding ceramic powder by ordinary compression molding or static pressure molding, and sintering it under normal pressure or pressure is suitable for manufacturing large parts, but it is also suitable for manufacturing parts with complex shapes. This tends to cause density differences, making it particularly difficult to form thin plates.

In slurry casting, ceramic powder is made into a thick slurry and then dehydrated and solidified on the surface of a porous mold, but it has drawbacks such as poor selection of mold material and weak strength of solidified ceramic powder. .

In addition, the method usually called a doctor blade is a method in which slurry is poured onto a substrate, a predetermined gap is created between the substrate and the slurry is scooped out with a doctor blade, and a thin plate is formed on the substrate. However, this method can only produce plate-shaped parts with simple shapes.

Furthermore, the method of depositing a ceramic thin film on a substrate by vapor phase deposition has a slow forming speed for the ceramic layer;
It is only suitable for producing extremely thin films.

(C) Disclosure of the Invention The present invention was discovered as a result of studies aimed at solving the various problems mentioned above in manufacturing ceramic parts using conventional techniques, and manufacturing ceramic parts with complex shapes, particularly thin-film ceramic parts. be.

That is, this invention applies the principle of electrophoresis to form a uniform and stable ceramic powder layer of a desired thickness (as thin as possible) on a substrate, and uses the principle of electrophoresis to form an irreversible layer of ceramic powder on a substrate, rather than simply depositing a slurry physically. They discovered a method for forming a ceramic powder layer on a base material.

The method of this invention will be explained in detail below.

First, since the method of this invention deposits ceramic powder on a base material by electrophoresis, the base material itself is conductive or has its surface treated to be conductive. is necessary.

In order for a particle to be electrophoresed in a liquid, it must become electrically charged in the liquid.

Since ceramic powder itself does not ionize, a charged carrier is attached to the ceramic powder, and by electrophoresis of the carrier, the ceramic powder is simultaneously migrated and deposited on the base material.

The carrier used at this time is one that can adhere to the ceramic powder and be ionized in the liquid.
stomach. However, it is undesirable to prevent sintering of the ceramic after electrophoretic deposition on the substrate.

As such carriers, polycarboxylic acid resins (anionic), polyamine resins (cationic), etc., which are used in ordinary electrodeposition coatings, can be used.

This carrier can serve as a primary binder for the ceramic powder, but a primary binder component may also be added to the carrier.

In this invention, the ceramic powder, which is the main raw material powder, needs to be sufficiently finely pulverized in order to be stably dispersed in a liquid and to facilitate electrophoresis, and for practical purposes, the particle size should be 40 μm or less. is preferred.

One type of ceramic powder may be used, or a mixed powder of two or more types may be used, and additives such as a sintering aid and a lubricant may be used as necessary.

In order to obtain a thin and uniform deposited layer of Reramix-carrier on a substrate, it is desirable that the conductivity of the deposited layer is low, as in the case of ordinary electrodeposition, but it is preferable that the conductivity of the deposited layer be low, as in the case of ordinary electrodeposition. If desired, make the deposited layer conductive by adding a conductive substance to the deposited layer on the base material obtained by electrophoresis, and then apply ceramics on top of it by electrophoresis. It is only necessary to deposit a deposited layer of the carrier.

After a deposited layer of ceramic carrier is deposited on the substrate in this manner, the liquid component is removed by drying, thereby obtaining the deposited layer as an intermediate product of ceramic carrier.

Next, this intermediate product (deposited layer) is heated to 300 to 1000°C to decompose or volatilize the carrier component in the deposited layer.

After that, before sintering the deposited layer, the deposited layer is separated from the conductive group 1, and a sintering strip A'1 is set according to the type and properties of the ceramic powder used as the raw material powder, and Perform pressure sintering.

The sintering temperature varies depending on the type of ceramic, but is usually 10
A range of 00 to 2000°C is suitable.

Note that the separation of the conductive group H from the deposited layer is not limited to the above-mentioned process before sintering the deposited layer, but may be performed in advance by separating the conductive groups H from the deposited layer, which prevents adhesion to the deposited layer electrodeposited on the base material. A method may also be used in which a molding agent or the like is applied and the base material is separated after final sintering to form a sintered body, and a thin ceramic sintered part can also be obtained by this method.

However, in the above-described method in which the deposited layer electrodeposited on the substrate is separated from the substrate before sintering, the substrate material does not need to have the same heat resistance as ceramics, so it is necessary to select from a wide range of materials. be able to.

In addition, as a method for separating and removing the base material, it is simple and preferable to perform a mold release treatment on the base material in advance and then mechanically separate the base material in a double manner.
Methods such as decomposition, volatilization, dissolution with chemicals, and electrochemical separation are possible, and these methods may be employed depending on the purpose.

For example, conductive treated wax, melting resin, or low melting point metals can be removed by heating and melting, carbon materials, organic compounds, etc. can be removed by heating and oxidation, and metals can generally be separated and removed by acid treatment, etc. I can do it.

The carrier components used with J3 and Relamix powder are:
As described above, since it is decomposed or volatilized from the deposited layer, it is preferable to select and use a substance that does not have any decomposition residue or whose residue does not adversely affect the final sintered body.

In addition, 300 to 100
The atmosphere during heating at 0° C. may be selected from air, oxygen, inert gas, etc. depending on the type of ceramics and carrier.

In short, this invention involves forming a deposited layer by electrodepositing a raw material powder made of a ceramic carrier on a conductive base material by electrophoresis, and then separating the deposited layer from the base material after drying. After heating and further sintering, 1q of ceramic parts are produced.In addition, after forming a deposited layer on MIJ, the resin is heated as it is, and the resin used as a carrier is hardened, and the ceramic powder and carrier are heated. If the mechanical strength of the deposited layer is increased and the base material is then separated, a strong deposited layer can be obtained.

Then, it is sintered at 1000 to 2000°C to obtain ceramic parts.

Furthermore, according to the method of the present invention, the following advantages can also be added.

In other words, electrophoretic deposition occurs only on conductive parts of the base material, so if a part of the base material is intentionally covered with an insulating film, no deposits will be formed on that part. be.

Utilizing this fact, it is also possible to produce patterned ceramic coatings or thin-walled parts by applying an insulating film in an arbitrary pattern to a base material.

In this invention, various ceramic powders such as alumina, zirconia, silicon nitride, silicon carbide, and sialon magnesia can be used.

Next, the present invention will be explained in detail with reference to examples.

Example 1 99% by weight of alumina powder was pulverized to an average particle size of 2 μm, and 1% by weight of magnesia powder, which had been similarly pulverized, was added and mixed uniformly.

This mixed powder was thoroughly kneaded with an acrylamide resin as a carrier, and then dispersed in a bath liquid.

Next, a stainless steel plate whose surface was coated with conductive grease was used as a cathode, and a curtainless plate was used as an anode, and these were immersed in the above bath solution in which a kneaded product of acrylamide resin and mixed powder was dispersed. While thoroughly stirring and mixing the liquid, a voltage of about 200 μm was applied for about 10 minutes to form a kneaded material layer with a thickness of about 50 μm on the shade plate.

After that, the stainless steel plate on which the kneaded material layer was formed was thoroughly washed with water and dried, and the carrier resin was baked at 170° C. for 20 minutes to form an inorganic film layer, and the stainless steel substrate was removed from the film layer hl. - The thus obtained inorganic film layer was fired at 600°C for about 1 hour, and then sintered at 1500°C to obtain a dense and uniform alumina sintered body.

Example 2 A mixed powder of 95% by weight of finely pulverized silicon carbide powder and 5% by weight of fine alumina powder was thoroughly kneaded with an epoxy-amide resin, and then dispersed in a bath liquid.

Next, a copper substrate as a cathode and a stainless steel plate as an anode were immersed in this bath solution, and the bath solution was stirred well for about 10 minutes.
A voltage of 200 V was applied for 1 minute.

Then, a kneaded material layer with a thickness of about 40 μm was formed on the copper substrate of the cathode.

Next, the copper substrate on which this kneaded material layer was formed was washed with water and dried, and then the carrier resin layer was baked at 180°C for 60 minutes.
The film layer had a thickness of 0 μm.

Next, the copper plate of the substrate was melted using H (J) at a concentration of 5%, leaving only the film layer, and then baked at 600°C for about 1 hour, and then
A dense and uniform carbonized (unglazed) viscous body was obtained by sintering at 00°C.

Patent applicant: Sumitomo Electric Industries, Ltd. Representative Patent Attorney Kazu 1) Akira

Claims (6)

[Claims] (1) Original F3+ whose main component is one or more types of ceramic powder, mixed with sintering aid, binder, etc.
When obtaining ceramic parts by sintering powder, a carrier that is ionized in a liquid is cross-attached to the raw material powder, and then this is dispersed in the liquid, and a conductive base material is immersed in the liquid. A direct current voltage is applied between the electrode and the counter electrode to deposit the raw material powder with the carrier attached onto the conductive base material, and then the base material is removed from the deposit, and the carrier in the deposit is decomposed or heated. A method for manufacturing ceramic parts, characterized by volatilization, followed by firing and sintering. (2) The ceramic according to claim 1, which uses a conductive base material that has been previously subjected to a mold release treatment to facilitate release from electrodeposited deposits on the base material. How the parts are manufactured. (3) The method for manufacturing a ceramic component according to claim 1, wherein the base material is removed by melting, decomposing, and volatilizing by heating. (4) The method for manufacturing a ceramic component according to claim 1, wherein the removal of the base material is performed by dissolving or decomposing the base material by chemical treatment. (5) The method for producing a ceramic component according to claim 1, wherein the carrier is a water-soluble or water-dispersible synthetic resin that can be ionized in a liquid. (6) A method for manufacturing a ceramic component according to claim 1, characterized in that the deposit layer has a conductivity of 10"Oc+n or less in specific resistance. 2. The method of manufacturing a ceramic component according to claim 1, wherein the deposit is partially formed using the same material to form a deposit layer with a desired pattern.