JPH09268075A - Ceramic material and production of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a ceramic material consisting of particles having fine particle sizes by constituting with a baked material obtained by mixing metal compounds with a specific compound and baking, and sufficiently performing a reaction by a baking of one time. SOLUTION: This ceramic material is constituted by a baked material obtained by mixing metal compounds e.g. as a metal oxide and/or a carbonic acid salt (e.g.; Y2 O3 , BaCO3 and CuO) with a nitric acid salt, preferably ammonium nitrate, and burning. As a result, a mean particle size of the ceramic (e.g.; 1-2-3YBCO ceramic material) particles constituting the baked material is 0.1-0.9μ. The nitric acid salt is preferably used in larger number of mols than that of the metal compounds. That is, since the metal compounds are converted into nitric acid salts having high reactivities and then baked, reactions among the metal compounds during the baking are accelerated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ceramics frequently used as electronic materials, magnetic materials, etc., and a method for manufacturing the same. Specifically, by mixing a metal compound containing a metal constituting a ceramic and a nitrate, and then baking the mixture, a reaction can be sufficiently performed by one-time baking,
The present invention relates to a ceramic produced as a fired body made of fine ceramic particles and a method for producing the same.

[0002]

2. Description of the Related Art Ceramics are widely used as a ceramic substrate used for electronic parts, other electronic materials, and also as a magnetic material. Among them, oxide ceramics are commonly used as a general material. .

Such oxide ceramics are usually manufactured through the following steps. That is, as shown in FIG. 3, the amount 101 of metal oxide or carbonate which is a metal compound containing a metal constituting ceramics is weighed.
Then, these are mixed 102, and this is molded 103
After that, firing 104 is performed. During this process, a reaction between oxides occurs in the baking 104 process. However, since their reactivity is low, the reaction rate is very slow, and there is a high possibility that a ceramic to be obtained with unreacted substances mixed cannot be obtained. Therefore, when actually manufacturing ceramics, after firing 104, crushing 105 is performed,
Mixing 102, molding 103, and firing 104 are performed again, and this is repeated 2-3 times.

[0004]

However, if firing is repeated many times in this way, particle growth proceeds, making it difficult to obtain ceramics composed of particles having a fine particle diameter, and ceramics having good characteristics are obtained. Hard to get.
The crushing process is a very complicated work, which is a factor that impairs productivity.

Further, in such oxide ceramics, especially high temperature oxide superconducting materials having a complicated molecular structure, the characteristics are greatly influenced by a small amount of the additive, so that the additive is uniformly dispersed. Is desired. However, in the above-described manufacturing method, since the reactivity of the oxide is extremely low, it is very difficult to replace the metal portion of the oxide with a trace amount of the additive and disperse the additive uniformly.

Therefore, the present invention has been proposed in view of the conventional circumstances, and the reaction is sufficiently performed without repeating the firing step many times, and a trace amount of the additive is uniformly dispersed,
It is an object of the present invention to provide a ceramic having fine characteristics and comprising ceramic particles having a fine particle diameter, and a method for producing the same.

[0007]

In order to solve the above problems, the ceramics of the present invention comprises a fired body obtained by mixing a metal compound such as a metal oxide or a carbonate with a nitrate and then firing the mixture. The average particle diameter of the ceramic particles constituting the fired body is 0.1 μm to 0.9 μm.

The method for producing ceramics of the present invention is characterized by mixing a metal compound such as a metal oxide or a carbonate with a nitrate, substituting the metal compound with a nitrate, and then firing these. is there.

When producing ceramics in this way, it is preferable to use ammonium nitrate as the nitrate. Other nitrates can be used, and nitric acid can also be used.

Further, in the case of producing ceramics as described above, it is preferable to mix a metal compound and a nitrate in a mole number equal to or greater than the mole number of the metal compound. When the amount of nitrate is less than the number of moles of the metal compound, the reaction between the nitrate and the metal compound is not sufficient and the unsubstituted metal compound remains, which has the effect of accelerating the reaction rate between the metal compounds during mixing and firing. Fades.

In the method for producing ceramics of the present invention, since the metal compound and the nitrate are mixed and then fired, the metal compound is replaced with the highly reactive nitrate, and then fired. The reaction between the above metal compounds is promoted, and the reaction is sufficiently performed by firing once.
Also, when a trace amount of an additive is added during mixing of the metal compound and the nitrate, the metal portion of the metal compound is likely to be in an ionic state, so this metal portion is easily replaced by the additive, Are evenly dispersed.

In the ceramic of the present invention manufactured by such a manufacturing method, the average particle diameter of the ceramic particles is as fine as 0.1 μm to 0.9 μm, and good characteristics are obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments to which the present invention is applied will be described based on experimental results. Here, 1-2-3YB is produced by the method for producing ceramics according to the present invention.
A CO ceramic was manufactured and the characteristics of this ceramic were investigated. For comparison, a 1-2-3YBCO ceramic was manufactured by a conventional ceramic manufacturing method, and the characteristics of this ceramic were investigated.

First, ceramics were manufactured by the method for manufacturing ceramics according to the present invention. That is, first, weighing 1 was performed as shown in FIG. Specifically, 112.91 g of Y ₂ O ₃ and ₃ of BaCO ₃ were used as metal compounds.
94.62 g of CuO and 238.65 g of CuO were weighed, and these oxides and carbonates and ammonium nitrate in a weight corresponding to 6 mol or more were weighed.

Mixing 2 was then carried out as shown in FIG.
That is, the above oxides and carbonates and ammonium nitrate were mixed in a mortar for about 5 to 10 minutes. At this time, oxygen of each of the oxides and carbonates is released, and the oxides and carbonates are replaced with nitrates. At this time, since water is also generated, the mixture becomes a paste. Further, since ammonium nitrate is sufficiently added, the entire oxides and carbonates are replaced with nitrates.

At this time, if a trace amount of an additive is added, the metal portion of the oxide and carbonate is likely to be in an ionic state, so that the metal portion is easily replaced by the additive, It is possible to disperse the additives uniformly.

Further, heating 3 was performed as shown in FIG. Specifically, the above mixture was heated on a hot plate at a temperature of about 150 to 200 ° C. to remove excess ammonium nitrate.

Subsequently, as shown in FIG. 1, molding 4 was performed. Specifically, after loosening the aggregated particles, a pressure of about 100 to 200 kg / mm ² is applied by a hydraulic press or the like,
It was molded into the desired shape.

Finally, as shown in FIG. 1, firing 5
Was done. That is, the firing temperature in air is 900
The temperature was set to ˜1000 ° C., and firing was performed for 3 hours to obtain ceramics.

When the particle diameter of the ceramic particles was examined by a metallographic microscope as a characteristic of this ceramic, it had a particle diameter of 0.1 to 0.3 μm. Also, when I tried X-ray diffraction on this ceramic,
Unreacted materials such as Ba ₂ CuO ₃ were not detected, and the crystal structure was orthorhombic. The X-ray diffraction chart is shown in FIG. The letters above or beside the peak in FIG. 2 are the indices of reflection.

For comparison, the respective oxides and carbonates were weighed as described above, then only these oxides and carbonates were mixed as described above, and these were molded and fired as described above. To produce ceramics. However, here, one firing time was set to 20 hours, and after firing, pulverization was performed to perform mixing, molding, and pulverization again, and this was repeated three times to produce ceramics.

When the particle size of the ceramic particles was examined with a metallographic microscope as a characteristic of this ceramic, it had a particle size of 1 to 3 μm. Moreover, when X-ray diffraction was performed on this ceramic, it was found that Ba ₂ C
Unreacted substances such as uO ₃ were detected.

From these results, after mixing the metal compound and the nitrate as in the method for producing a ceramic of the present invention,
If these are fired, the metal compound is fired after being replaced with a highly reactive nitrate, and the reaction between the metal compounds at the time of firing is promoted, and the reaction can be performed sufficiently by one firing. It was confirmed that

In the ceramic of the present invention manufactured by such a manufacturing method, the average particle diameter of the ceramic particles is fine within the range of 0.1 μm to 0.9 μm, and has good characteristics. It was confirmed that

In the method for producing ceramics of the present invention, since it is not necessary to repeat firing, it is not necessary to perform a complicated pulverizing step and productivity is improved. In addition, the step of mixing the metal compound and the nitrate can be incorporated into a normal manufacturing process, which does not increase the number of unnecessary manufacturing processes and does not impair the productivity.

[0026]

As is apparent from the above description, in the method for producing ceramics of the present invention, the metal compound and the nitrate are mixed and then baked, so that the metal compound is converted into a highly reactive nitrate. It will be fired after being substituted, the reaction between the metal compounds during firing is promoted,
The reaction is sufficiently carried out by one firing, and the productivity is improved.

In the ceramics manufacturing method of the present invention, since it is not necessary to repeat firing, it is not necessary to perform a complicated crushing step, and the productivity is improved. In addition, the step of mixing the metal compound and the nitrate can be incorporated into a normal manufacturing process, which does not increase the number of unnecessary manufacturing processes and does not impair the productivity.

Further, in the method for producing a ceramic of the present invention, if a small amount of an additive is added when the metal compound and the nitrate are mixed, the metal portion of the metal compound is likely to be in an ionic state. The portion is easily replaced by the additive, the additive is uniformly dispersed, and the characteristics of the ceramics produced are easily adjusted.

In the ceramic of the present invention manufactured by such a manufacturing method, the average particle diameter of the ceramic particles is as fine as 0.1 μm to 0.9 μm, and good characteristics are obtained.

[Brief description of drawings]

FIG. 1 is a chart showing steps of a method for producing ceramics to which the present invention is applied.

FIG. 2 is a chart showing the results of X-ray diffraction of ceramics to which the present invention is applied.

FIG. 3 is a chart showing the steps of a conventional ceramic manufacturing method.

Claims (4)

[Claims] 1. A fired body obtained by mixing a metal compound and a nitrate and firing the mixture. The average particle size of ceramic particles constituting the fired body is 0.1 μm to 0.9 μm.
Ceramics characterized by being 2. A method for producing ceramics, which comprises mixing a metal compound and a nitrate and then firing these. 3. The method for producing ceramics according to claim 2, wherein the nitrate is ammonium nitrate. 4. The method for producing ceramics according to claim 2, wherein the metal compound is mixed with a nitrate in a mole number equal to or more than the mole number of the metal compound.