JPH0421571A - Calcination of ceramic - Google Patents
Calcination of ceramicInfo
- Publication number
- JPH0421571A JPH0421571A JP2123627A JP12362790A JPH0421571A JP H0421571 A JPH0421571 A JP H0421571A JP 2123627 A JP2123627 A JP 2123627A JP 12362790 A JP12362790 A JP 12362790A JP H0421571 A JPH0421571 A JP H0421571A
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- stage
- ceramic
- rate
- raised
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000919 ceramic Substances 0.000 title claims abstract description 12
- 238000001354 calcination Methods 0.000 title abstract 4
- 238000005245 sintering Methods 0.000 abstract description 7
- 239000011261 inert gas Substances 0.000 abstract description 6
- 238000000034 method Methods 0.000 abstract description 3
- 229910052581 Si3N4 Inorganic materials 0.000 abstract 1
- 239000007789 gas Substances 0.000 abstract 1
- 238000010304 firing Methods 0.000 description 9
- 238000010438 heat treatment Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000007796 conventional method Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Landscapes
- Ceramic Products (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、セラミックス製品、特に、厚肉製品の成形に
適する焼成方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a firing method suitable for molding ceramic products, particularly thick-walled products.
（従来の技術）
例えば、直径１５ｍ５以上の比較的厚肉の円柱状セラミ
ックス製品を焼成する場合、薄肉製品の場合より、昇温
速度を下げて焼成している。(Prior Art) For example, when firing a relatively thick cylindrical ceramic product with a diameter of 15 m or more, the heating rate is lowered than that for a thin product.
その−例を次に挙げる。An example of this is given below.
使用セラミックスの種類：Ｓｉ、Ｎ。Types of ceramics used: Si, N.
原料粉の比表面積 、１２曹２／ｇ助剤系
・アルミナ−イツトリア上記組成の材料で円柱
状に成形したワークを不活性ガス雰囲気炉中に入れ、第
３図に示すように、１２００°Ｃに到達するまでの第■
段階では、低圧不活性ガス雰囲気中で１０℃／ｗｉｎの
ように急速に加熱し、次いて鎖線で示すように不活性カ
ス圧を上げ、最高温度に到達するまでの第■段階ては、
１’Ｃ／■ｉｎのように昇温速度を下げ、この最高温度
に９時間保持して焼成する。Specific surface area of raw material powder, 12 Sodium 2/g Auxiliary system
・Alumina-Ittria A workpiece formed into a cylindrical shape with the above-mentioned composition is placed in an inert gas atmosphere furnace, and as shown in Figure 3, it is heated until it reaches 1200°C.
In the stage (2), heating is carried out rapidly at 10°C/win in a low-pressure inert gas atmosphere, and then the inert gas pressure is increased as shown by the chain line until the maximum temperature is reached.
The heating rate is reduced to 1'C/inch and the maximum temperature is maintained for 9 hours for firing.
従来、ワークか薄肉の場合には、第■段階の昇温速度を
２℃／■ｉｎに設定していた。Conventionally, when the workpiece is thin, the temperature increase rate in the second stage has been set to 2° C./in.
成形体か大きくなって、直径か２２１■程度となると、
全体か緻密な焼結体か得られず、第４図に示すように、
ワークｌの破線て示す中央部２に芯のようなものか出来
、また、気孔も多く発生する。When the molded object becomes large and has a diameter of about 221 cm,
A whole or dense sintered body could not be obtained, as shown in Figure 4.
A wick-like substance is formed in the central part 2 of the work l, indicated by the broken line, and many pores are also generated.
本発明は前記の課題を解決し、大型の成形体ても全体か
緻密な焼結体か得られ、製品精度の向上を図ることを目
的とするものである。The object of the present invention is to solve the above-mentioned problems, to obtain a whole or dense sintered body even in a large molded body, and to improve product precision.
〔課題を解決するための手段及び作用〕本発明は、１４
００℃付近までの昇温速度に対し、これに続＜ １５５
０℃付近までの昇温速度を０，５°Ｃ／ｗｉｎ程度に下
げ、次いて昇温速度を２℃７１０程度に七げて最高温度
とし、該最高温度に所定時間保持するセラミックスの焼
成方法である。[Means and effects for solving the problem] The present invention has 14
For the temperature increase rate up to around 00℃, following this < 155
A ceramic firing method in which the temperature increase rate to around 0℃ is lowered to about 0.5℃/win, then the temperature increase rate is increased to about 2℃710 to reach the maximum temperature, and the maximum temperature is maintained for a predetermined time. It is.
１２００℃以下の温度ては、焼結か進行しないので急速
に昇温して短時間て温度を上げ、次の１４００°Ｃ付近
まては大きな寸法収縮か発生しないのて１次の段階より
も昇温速度を高く設定する。At temperatures below 1,200°C, sintering does not proceed, so the temperature is raised rapidly and in a short period of time, and until the next temperature reaches around 1,400°C, large dimensional shrinkage does not occur, which is better than the first stage. Set the heating rate high.
１４００℃〜１６５０℃付近で急激な収縮か発生するた
め、昇温速度を０．５℃／ｍｉｎ程度と低くし、全体を
均一に収縮させて高密度化させる。Since rapid shrinkage occurs around 1400°C to 1650°C, the temperature increase rate is set to be as low as about 0.5°C/min to uniformly shrink the entire product and increase its density.
１６５０°Ｃ付近以上の段階ては、収縮は殆ど終り、粒
成長か進行するのて、昇温速度を２°Ｃ／ｌ１ｉｎ程度
に上げ、巨大粒の発生を防いて強度の低下を抑制し１、
次に、従来と同様に高温に数時間保持して焼成体全体を
緻密に焼結する。When the temperature is around 1650°C or higher, shrinkage has almost finished and grain growth has progressed, and the temperature increase rate is increased to about 2°C/l1in to prevent the generation of giant grains and suppress the decrease in strength. ,
Next, the entire fired body is sintered densely by maintaining it at a high temperature for several hours as in the conventional method.
（実施例） 本発明の実施例を図面について説明する。(Example) Embodiments of the present invention will be described with reference to the drawings.
第１図は、本発明の−・実施例の昇温速度を示す図、第
２図は焼成時における焼成温度とワーク密度の変化を示
すものである。FIG. 1 is a diagram showing the temperature increase rate in Examples of the present invention, and FIG. 2 is a diagram showing changes in firing temperature and workpiece density during firing.
焼成時におけるワーク密度は、第２ＵＡに示すように、
１２００°Ｃ以下の温度では、殆ど焼結か進行せず、ワ
ークの相対密度も僅かしか上からない。The work density during firing is as shown in 2nd UA,
At temperatures below 1200°C, sintering hardly progresses and the relative density of the work increases only slightly.
１２００℃〜１４００℃の段階で焼結か進行するか、大
きな収縮はまた発生しない。次の１４００°Ｃ〜１５５
０°Ｃの段階て急激な収縮か発生し、最高相対密度に到
達し、その後は、温度か上昇しても相対密度は変化しな
い。Sintering progresses at a temperature of 1200°C to 1400°C, and no large shrinkage occurs. Next 1400°C ~ 155
At 0°C, rapid contraction occurs and the highest relative density is reached, after which the relative density does not change even if the temperature increases.
第１図に示すように、１２００°Ｃ以下の第ｍ段階では
、焼結か進行しないため、低圧不活性ガス雰囲気中で１
０℃／ｍｉｎの昇温速度て急速に昇温して短時間で温度
を上げる。As shown in Fig. 1, sintering does not proceed at the m-th stage below 1200°C, so 1.
The temperature is raised rapidly at a heating rate of 0°C/min to raise the temperature in a short time.
次いでｌｌＪｍて示すように不活性ガス圧を上げ、１２
００°Ｃ〜１４００°Ｃの第ｎ段階ては、表面拡散によ
る焼結が進行するが、大きな寸法収縮かまた発生しない
ので１次の第ｍ段階よりも昇温速度を高く１℃／謬１０
に設定する。Next, increase the inert gas pressure as shown by 11Jm, and
In the n-th stage from 00°C to 1400°C, sintering progresses due to surface diffusion, but large dimensional shrinkage does not occur, so the heating rate is set higher than in the first m-th stage by 1°C/10°C.
Set to .
１４００℃〜１６５０”Ｃの第ｍ段階ては、体積拡散に
よる焼結か進行し、急激な収縮か発生するため 昇温速
度を最も低い０，５°Ｃ／■ｉｎとし、全体を均一に収
縮させて高密度化させる。At the m-th stage from 1400℃ to 1650''C, sintering progresses due to volume diffusion and rapid shrinkage occurs, so the temperature increase rate is set to the lowest, 0.5℃/inch, and the entire product contracts uniformly. to increase the density.
１６５０°Ｃ以上の第■段階ては、収縮は殆ど終り粒成
長か進行するのて、昇温速度を２°Ｃ／■ｉｎに七げ、
巨大粒の発生を防いて強度の低下を抑制する。At the stage 2 above 1650°C, shrinkage has almost finished and grain growth has progressed, so the temperature increase rate is increased to 2°C/inch.
Prevents the formation of large grains and suppresses the decrease in strength.
次に、従来と同様に高温に数時間保持してワーク全体を
緻密に焼結する。Next, the entire workpiece is sintered densely by holding it at a high temperature for several hours as in the conventional method.
上記実施例における第１段階及び第ｎ段階の昇温速度は
、これらを何れも０．５９Ｃ／ｗｉｎとしても、同等の
焼結体か得られる筈であるか、焼成サイクル短縮のため
、昇温速度を可能な範囲て上げたものである。In the above example, the temperature increase rate in the first stage and the nth stage is 0.59C/win, but the same sintered body should be obtained. The speed has been increased as much as possible.
次に、ワークの寸法を変えた焼成体の相対密度を測定し
た結果を別表に示す。Next, the results of measuring the relative densities of fired bodies with different workpiece dimensions are shown in the attached table.
別表から明らかなように、従来法では出来なかった、直
径６０ｍｍ、長さ８５■■の円柱体のような大型の製品
についても、緻密な焼成体か得られた。As is clear from the attached table, dense fired products were obtained even for large products such as cylinders with a diameter of 60 mm and a length of 85 mm, which could not be produced using the conventional method.
別表 注１）数字はすべて相対密度％を表す。Separate table Note 1) All numbers represent relative density%.
汀２）○は芯残り無し、×は有り。2) ○ means no core remains, × means there is.
本発明は、大型の成形体でも全体か緻密な焼結体か得ら
れ、製品精度の向上を図ることかてきる効果か有る。The present invention has the effect of making it possible to obtain a dense sintered body even in the case of a large-sized molded body, thereby improving the precision of the product.
【図面の簡単な説明】
第１図は本発明の一実施例の昇温速度を示す図、第２図
は焼成時における焼成温度とワーク密度の変化を示す図
、第３図は従来の昇温速度を示す図、第４図は従来法に
よる焼結体の断面図である。[Brief Description of the Drawings] Figure 1 is a diagram showing the temperature increase rate of an embodiment of the present invention, Figure 2 is a diagram showing changes in firing temperature and workpiece density during firing, and Figure 3 is a diagram showing the temperature increase rate of an embodiment of the present invention. FIG. 4, which shows the temperature velocity, is a cross-sectional view of a sintered body made by a conventional method.
Claims (1)
５０℃付近までの昇温速度を０．５℃／ｍｉｎ程度に下
げ、次いて昇温速度を２℃／ｍｉｎ程度に上げて最高温
度とし、該最高温度に所定時間保持することを特徴とす
るセラミックスの焼成方法。16 following this for a temperature increase rate of around 1400℃
It is characterized by lowering the temperature increase rate to around 50℃ to about 0.5℃/min, then increasing the temperature increase rate to about 2℃/min to reach the maximum temperature, and maintaining the temperature at the maximum temperature for a predetermined period of time. How to fire ceramics.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2123627A JP2926881B2 (en) | 1990-05-14 | 1990-05-14 | Ceramic firing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2123627A JP2926881B2 (en) | 1990-05-14 | 1990-05-14 | Ceramic firing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0421571A true JPH0421571A (en) | 1992-01-24 |
| JP2926881B2 JP2926881B2 (en) | 1999-07-28 |
Family
ID=14865269
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2123627A Expired - Lifetime JP2926881B2 (en) | 1990-05-14 | 1990-05-14 | Ceramic firing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2926881B2 (en) |
-
1990
- 1990-05-14 JP JP2123627A patent/JP2926881B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2926881B2 (en) | 1999-07-28 |
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