JPH07115915B2 - Alumina refractory manufacturing method - Google Patents
Alumina refractory manufacturing methodInfo
- Publication number
- JPH07115915B2 JPH07115915B2 JP63027275A JP2727588A JPH07115915B2 JP H07115915 B2 JPH07115915 B2 JP H07115915B2 JP 63027275 A JP63027275 A JP 63027275A JP 2727588 A JP2727588 A JP 2727588A JP H07115915 B2 JPH07115915 B2 JP H07115915B2
- Authority
- JP
- Japan
- Prior art keywords
- weight
- particles
- refractory
- alumina
- particle size
- 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.)
- Expired - Lifetime
Links
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 title claims description 17
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 239000002245 particle Substances 0.000 claims description 35
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 30
- 238000010304 firing Methods 0.000 claims description 12
- 239000011819 refractory material Substances 0.000 claims description 9
- 238000009826 distribution Methods 0.000 claims description 6
- 239000011882 ultra-fine particle Substances 0.000 claims description 3
- 238000004901 spalling Methods 0.000 description 14
- 238000006243 chemical reaction Methods 0.000 description 9
- 239000002994 raw material Substances 0.000 description 8
- 239000000758 substrate Substances 0.000 description 7
- 229910000859 α-Fe Inorganic materials 0.000 description 7
- 230000008602 contraction Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000001816 cooling Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 239000013078 crystal Substances 0.000 description 4
- 238000010298 pulverizing process Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000011362 coarse particle Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical group [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
Description
【発明の詳細な説明】 ［発明の目的］ （産業上の利用分野） 本発明は、耐スポーリング性の改善及び被焼成品との反
応抑制を可能にできるアルミナ質耐火物の製造方法に関
する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for producing an alumina refractory material capable of improving spalling resistance and suppressing reaction with a product to be fired.
（従来の技術） 従来、例えば電子部品用フェライトを焼成するための窯
道具はほとんどアルミナを主成分とするアルミナ耐火物
により形成されていた。しかし、これにはアルミナの熱
膨脹率が大であるため、耐スポーリング性に劣るという
欠点がある上に、焼成時に被焼成時たるフェライトとの
間で化学反応が生じ、製品の磁気的及び電気的特性を低
下させるという問題があった。また、耐スポーリング性
を向上させるべく、アルミナ含有率を80〜95％とし、残
りに主として二酸化珪素を含有させて焼成したものも供
されてはいるが、これでは被焼成品における粒成長が促
され、製品の磁気的及び電気的特性が低下するという問
題が残されている。(Prior Art) Conventionally, for example, most kiln tools for firing ferrite for electronic parts are made of alumina refractory containing alumina as a main component. However, this has the disadvantage of poor spalling resistance due to the high coefficient of thermal expansion of alumina, and also causes a chemical reaction with the ferrite, which is the material to be fired during firing, resulting in magnetic and electrical There is a problem that the physical characteristics are deteriorated. In addition, in order to improve the spalling resistance, an alumina content rate of 80 to 95% and the remaining mainly containing silicon dioxide are also provided, and the one obtained by firing is used. The problem remains that the magnetic and electrical properties of the product are impaired.
そこで本出願人は、既にアルミナを主成分とし、これに
所定量の単斜晶形ジルコニアを添加して成るアルミナ質
耐火物の発明を完成させ、これを出願した（特願昭60−
178036号）。これによれば、フェライト焼成時における
被焼成品との反応がジルコニアの存在のために抑制され
ると共に、ジルコニアの相転移に伴う異常体積膨脹によ
り骨材粒子周囲の基質部に無数のマイクロクラックが発
生するため、このマイクロクラックにより耐火物内部の
応力が緩和されて耐スポーリング性が改善されるという
効果が得られる。Therefore, the present applicant has completed an invention of an alumina refractory material, which is mainly composed of alumina and to which a predetermined amount of monoclinic zirconia is added, and applied for this (Japanese Patent Application No. 60-
No. 178036). According to this, while the reaction with the product to be fired during ferrite firing is suppressed due to the presence of zirconia, countless microcracks are formed in the matrix part around the aggregate particles due to abnormal volume expansion accompanying the phase transition of zirconia. Since the microcracks are generated, the stress inside the refractory is relaxed, and the effect of improving the spalling resistance is obtained.
（発明が解決しようとする課題） しかし、特に耐スポーリング性をより向上させることは
耐火物の耐久性を大きく高めることになるので、望まし
い。そこで、本発明者らは、被焼成品たるフェライトと
の反応抑制は勿論のこと、併せて耐スポーリング性の一
層の向上を図ることを目的として研究を重ね、その結
果、本発明を完成させるに至った。(Problems to be solved by the invention) However, further improvement of spalling resistance is particularly desirable because it greatly increases the durability of the refractory. Therefore, the present inventors have conducted research for the purpose of not only suppressing the reaction with ferrite to be fired but also further improving the spalling resistance, and as a result, completed the present invention. Came to.
［発明の構成］ （課題を解決するための手段） 一般に、耐火物を製造する際における原料粒子の過剰な
微粉化は、基質部の収縮を招いてクラック発生を引き起
こす。このことは、過大なクラック発生により不良品率
の増大をもたらず可能性を意味するため、原料粒子の過
剰な微粉化は極力避けるべきとするのが従来の技術的常
識であった。本発明は、斯かる技術的常識に反し、原料
粒子の微粉化による基質部の収縮を積極的に利用しよう
とするものである。このために、本発明では、本出願人
が先に出願した特願昭60−178036号に比べ、原料粒子の
粒度分布を微粉側及び粗粒側に偏らせ、その分、中間的
粒度の原料粒子を少なくするようにしている。具体的に
は、本発明に係るフェライト焼成用アルミナ質耐火物の
製造方法は、99〜92重量％のアルミナ粒子及び１〜８重
量％の単斜晶形ジルコニア粒子を下記の粒度分布となる
ようにして混合し、混練して成形後、1400℃以上の温度
で焼成することにより骨材粒子の周囲に無数のマイクロ
クラックを発生させるようにしたことを特徴とするもの
である。[Structure of the Invention] (Means for Solving the Problems) In general, excessive pulverization of raw material particles during production of a refractory material causes contraction of a substrate portion to cause cracking. This means that there is a possibility that the rate of defective products will not increase due to the occurrence of excessive cracks. Therefore, it was the conventional technical common sense that excessive pulverization of raw material particles should be avoided as much as possible. Contrary to such technical common sense, the present invention intends to positively utilize the shrinkage of the substrate portion due to the pulverization of the raw material particles. For this reason, in the present invention, as compared with Japanese Patent Application No. 60-178036 filed by the present applicant earlier, the particle size distribution of the raw material particles is biased toward the fine powder side and the coarse particle side, and the raw material having an intermediate particle size is accordingly produced. I try to reduce the number of particles. Specifically, the method for producing an alumina refractory material for ferrite firing according to the present invention comprises 99-92% by weight of alumina particles and 1-8% by weight of monoclinic zirconia particles having the following particle size distribution. It is characterized in that innumerable microcracks are generated around the aggregate particles by mixing, kneading and molding, and then firing at a temperature of 1400 ° C. or higher.
（ａ）500μ以上 35〜55重量％ （ｂ）500〜100μ 10〜25重量％ （ｃ）100〜50μ ５重量％以下 （ｄ）50μ以下 15〜45重量％ （ｅ）50μ以下の粒度域に粒径５μ以下の超微粒子が50
重量％以上含まれること （作用） 周知の通り、スポーリングは、耐火物が加熱・冷却され
ることによる熱膨脹・熱収縮に起因して耐火物内部に応
力が発生し、これが組織の弾性限界を越えることによっ
て発生する。従って、熱膨脹・熱収縮に起因する耐火物
内部の応力を緩和できれば、耐スポーリング性が向上す
る。(A) 500μ or more 35-55% by weight (b) 500-100μ 10-25% by weight (c) 100-50μ 5% by weight or less (d) 50μ or less 15-45% by weight (e) In the particle size range of 50μ or less 50 ultrafine particles with a particle size of 5μ or less
As it is well known, spalling causes stress inside the refractory due to thermal expansion / contraction due to heating / cooling of the refractory, which causes the elastic limit of the tissue. It is caused by crossing. Therefore, if stress inside the refractory due to thermal expansion / contraction can be relaxed, spalling resistance is improved.
さて、上記手段のように原料粒子の粒度分布を、従来の
耐火物の一般的な製造方法におけるそれに比べて微粉側
に偏らせると、焼成時において基質部は収縮傾向を呈す
る。このため、上述のような粒度分布のもとでは、焼成
収縮に伴い基質部に無数のマイクロクラックが発生す
る。これにより、耐火物の熱膨脹・熱収縮に起因して発
生する耐火物内部の応力は上記マイクロクラックにより
緩和されるようになり、もって組織全体の破壊に至るこ
とが未然に防止される。When the particle size distribution of the raw material particles is biased toward the fine powder side as compared with that in the conventional method for producing a refractory material as in the above means, the substrate portion tends to shrink during firing. Therefore, under the above-described particle size distribution, numerous microcracks are generated in the substrate portion due to firing shrinkage. As a result, the stress inside the refractory caused by the thermal expansion and contraction of the refractory is relieved by the microcracks, and it is possible to prevent the destruction of the entire structure.
一方、上記手段のように製造した基質部組織は、無数の
微細なアルミナ結晶の粒界にジルコニア結晶が散在せる
状態となる。ここで、単斜晶形ジルコニアは、常温から
加熱されると正方晶形に転移し、この後冷却されると、
周知のように約900℃を境に正方晶形から単斜晶形に転
移して急激な体積膨脹を呈する。このため、本発明では
ジルコニア結晶の相転移に伴う体積膨脹によりジルコニ
ア結晶周囲が強制的に押し広げられ、この結果、焼成収
縮による効果と併せて適度なマイクロクラックが基質部
内に発生することになり、もって耐火物内部の応力緩和
が一層確実化される。尚、このようなマイクロクラック
は、電子顕微鏡又は実体顕微鏡にて確認することがで
き、図面中第１図に本発明方法により製造した耐火物の
実体顕微鏡写真（倍率50倍）を、第２図に従来方法によ
り製造した耐火物の同等写真を示した。On the other hand, the matrix structure produced as in the above means is in a state in which zirconia crystals are scattered in the grain boundaries of countless fine alumina crystals. Here, the monoclinic zirconia is transformed into a tetragonal form when heated from room temperature, and then cooled,
As is well known, at a temperature of about 900 ° C., the tetragonal system transforms to a monoclinic system and exhibits a rapid volume expansion. Therefore, in the present invention, the volume expansion accompanying the phase transition of the zirconia crystal is forcedly spread around the zirconia crystal, and as a result, an appropriate microcrack is generated in the substrate part together with the effect of the firing shrinkage. Therefore, the stress relaxation inside the refractory is further ensured. Such microcracks can be confirmed with an electron microscope or a stereomicroscope, and in FIG. 1 a drawing is a stereomicrograph of a refractory material manufactured by the method of the present invention (magnification 50 times). An equivalent photograph of the refractory produced by the conventional method is shown in Fig.
そして、本発明者らは、多くの実験・研究の結果、アル
ミナ及び単斜晶形ジルコニアの原料粒子の割合及び粒度
分布が上記手段に記載した範囲内にある場合に最も優れ
た効果を奏することを見出だした。この中では、アルミ
ナ粒子及びジルコニア粒子の双方を含む50μｍ以下の粒
度域に粒径５μｍ以下の超微粒子が50重量％以上含まれ
ることが最も重要である。これにより適度な焼成収縮が
確保されるからである。また単斜晶形ジルコニアの含有
率の下限値は上述の作用効果を奏するための最低の必要
値である。一方、含有率が上限値を越えると、耐スポー
リング性がかえって低下する。これは、ジルコニアの体
積膨脹に起因するマイクロクラックの発生量が過剰にな
るためと考えられる。また、500μｍ以上の粒子の含有
量を比較的多くしているのは、中間的粒度の粒子よりも
このような粗粒を多くしたほうが適度なマイクロクラッ
クを発生させ易いからである。尚、500μｍ以上の粒子
は35〜55重量％の範囲にあることが必要であるが、その
中でも40〜50重量％の範囲内にあることが最も好まし
い。また、500〜100μｍの粒子は10〜25重量％の範囲に
あることが必要であるが、10〜20重量％の範囲にあるこ
とが最も好ましい。The inventors of the present invention have shown that, as a result of many experiments and studies, when the ratio of the raw material particles of alumina and monoclinic zirconia and the particle size distribution are within the range described in the above means, the most excellent effect is exhibited. I found it. Among these, it is most important that 50% by weight or more of ultrafine particles having a particle size of 5 μm or less be contained in a particle size range of 50 μm or less containing both alumina particles and zirconia particles. This is because an appropriate firing shrinkage is secured. The lower limit of the content of monoclinic zirconia is the minimum necessary value for achieving the above-mentioned effects. On the other hand, if the content exceeds the upper limit, the spalling resistance is rather deteriorated. It is considered that this is because the amount of microcracks generated due to the volume expansion of zirconia becomes excessive. Further, the reason why the content of particles having a size of 500 μm or more is relatively large is that an appropriate amount of microcracks is more likely to occur when the number of coarse particles is larger than that of particles having an intermediate size. The particles having a size of 500 μm or more need to be in the range of 35 to 55% by weight, and most preferably in the range of 40 to 50% by weight. Further, the particles of 500 to 100 μm must be in the range of 10 to 25% by weight, but the range of 10 to 20% by weight is most preferable.
また、単斜晶形ジルコニアの添加は、上述のように耐火
物の耐スポーリング性の改善するのみならず、後述する
実施例から実証されるように、被焼成品と耐火物との接
触面の化学反応を抑制する。これにより、電子部品用の
フェライトを焼成する場合でも、被焼成品の磁気的及び
電気的特性が低下することを確実に防止することができ
る。Further, addition of monoclinic zirconia not only improves the spalling resistance of the refractory as described above, but as demonstrated by the examples described later, the contact surface of the article to be fired and the refractory Suppresses chemical reactions. As a result, even when the ferrite for electronic components is fired, it is possible to reliably prevent the magnetic and electrical characteristics of the fired product from being degraded.
（実施例） 以下本発明をいくつかの実施例により例証する。(Examples) The present invention will be illustrated by some examples below.
各実施例及び比較例における製造方法は次の通りであ
る。次表に示した組成及び粒度の各調合物に一般的な有
機バインダー0.6％、水4.5％を添加して混練し、これを
油圧圧縮成形機により800kg/cm2で加圧して270×270×1
0mmの寸法に成形し、定法により乾燥後、1650℃で焼成
した。そして、このようにして得た試料について、見掛
け気孔率、かさ比重及び曲げ強度（室温及び熱間）を測
定すると共に、耐スポーリング性テスト及び耐反応性テ
ストを実施した。耐スポーリング性テストは、各試料に
200×200×5mmの大きさの耐火材板を載置し、トンネル
式電気炉内を30分で通過させることにより500℃、550℃
及び600℃に夫々昇温させて室温に冷却した後の亀裂発
生状況を観察することにより行なった。500℃に加熱し
て冷却した後にクラックが発生したものを「×」、550
℃に加熱して冷却した後にクラックが発生したものを
「△」、そして600℃に加熱して冷却した後にクラック
が発生したものを「○」にて表わしてある。また、耐反
応性テストは、上記各試料の上にフェライト素地を載置
して1350℃にて焼成した後の磁気的特性を測定すること
により行なった。The manufacturing method in each example and comparative example is as follows. 0.6% of a general organic binder and 4.5% of water are added to each composition having the composition and particle size shown in the following table, and the mixture is kneaded, and this is pressurized by a hydraulic compression molding machine at 800 kg / cm 2 to 270 × 270 × 1
It was molded into a size of 0 mm, dried by a conventional method, and then baked at 1650 ° C. Then, apparent porosity, bulk specific gravity, and bending strength (room temperature and hot) of the sample thus obtained were measured, and a spalling resistance test and a reaction resistance test were performed. A spalling resistance test is performed for each sample.
Place a refractory plate with a size of 200 x 200 x 5 mm and let it pass through a tunnel-type electric furnace in 30 minutes to 500 ℃, 550 ℃
It was performed by observing the state of crack initiation after heating to 600 ° C. and cooling to room temperature. “X” indicates that cracks occurred after heating to 500 ℃ and cooling, 550
The ones in which cracks were generated after heating to 600 ° C. and cooling were represented by “Δ”, and those in which cracks were generated after heating to 600 ° C. and cooling were represented by “◯”. The reaction resistance test was carried out by placing a ferrite substrate on each of the above-mentioned samples and firing it at 1350 ° C. to measure the magnetic characteristics.
次の第１乃至第４表から明らかなように、各実施例は耐
スポーリング性及び耐反応性において比較例に比べて良
好な結果を示すものである。As is clear from the following Tables 1 to 4, each example shows a better result in spalling resistance and reaction resistance than the comparative example.
［発明の効果］ 以上述べたように、本発明の製造方法によれば、原料粒
子を微粉化することによる基質部の収縮を積極的に利用
すると共に単斜晶形ジルコニアの体積膨脹を利用して耐
火物の基質部に極めて微細な無数のマイクロクラックを
発生させることができる。これにより、耐火物の熱膨張
・熱収縮に起因する耐火物内部の応力を緩和することが
できて耐スポーリング性を大幅に改善することができ、
しかも、被焼成品との反応を抑えて製品の特性低下を防
止することができるという優れた効果を奏するものであ
る。 [Effects of the Invention] As described above, according to the production method of the present invention, the contraction of the matrix portion by pulverizing the raw material particles is positively utilized and the volume expansion of the monoclinic zirconia is utilized. It is possible to generate an extremely fine number of microcracks in the substrate portion of the refractory. Thereby, the stress inside the refractory due to the thermal expansion and contraction of the refractory can be relaxed, and the spalling resistance can be greatly improved.
In addition, it has an excellent effect that the reaction with the product to be fired can be suppressed and the characteristic deterioration of the product can be prevented.
第１図は本発明に係るアルミナ質耐火物の一例を示す組
織写真、第２図は従来のアルミナ質耐火物を示す組織写
真である。FIG. 1 is a structural photograph showing an example of an alumina refractory material according to the present invention, and FIG. 2 is a structural photograph showing a conventional alumina refractory material.
Claims (1)
量％の単斜晶形ジルコニア粒子を下記の粒度分布となる
ようにして混合し、混練して成形後、1400℃以上の温度
で焼成することにより骨材粒子の周囲に無数のマイクロ
クラックを発生させるようにしたことを特徴とするアル
ミナ質耐火物の製造方法。 （ａ）500μ以上 35〜55重量％ （ｂ）500〜100μ 10〜25重量％ （ｃ）100〜50μ ５重量％以下 （ｄ）50μ以下 15〜45重量％ （ｅ）50μ以下の粒度域に粒径５μ以下の超微粒子が50
重量％以上含まれること1. 99 to 92% by weight of alumina particles and 1 to 8% by weight of monoclinic zirconia particles are mixed so as to have the following particle size distribution, kneaded and molded, and then at a temperature of 1400 ° C. or higher. A method for producing an alumina refractory material, characterized in that innumerable microcracks are generated around the aggregate particles by firing. (A) 500μ or more 35-55% by weight (b) 500-100μ 10-25% by weight (c) 100-50μ 5% by weight or less (d) 50μ or less 15-45% by weight (e) In the particle size range of 50μ or less 50 ultrafine particles with a particle size of 5μ or less
Must be contained by weight% or more
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63027275A JPH07115915B2 (en) | 1988-02-08 | 1988-02-08 | Alumina refractory manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63027275A JPH07115915B2 (en) | 1988-02-08 | 1988-02-08 | Alumina refractory manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01203262A JPH01203262A (en) | 1989-08-16 |
| JPH07115915B2 true JPH07115915B2 (en) | 1995-12-13 |
Family
ID=12216526
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63027275A Expired - Lifetime JPH07115915B2 (en) | 1988-02-08 | 1988-02-08 | Alumina refractory manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07115915B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0832585B2 (en) * | 1989-09-13 | 1996-03-29 | 株式会社村田製作所 | Heat shock resistant firing setter |
| JPH0832586B2 (en) * | 1989-09-13 | 1996-03-29 | 株式会社村田製作所 | Heat shock resistant firing setter |
| CN107646026B (en) | 2015-06-01 | 2021-03-26 | 圣戈本陶瓷及塑料股份有限公司 | Refractory article and method of forming the same |
-
1988
- 1988-02-08 JP JP63027275A patent/JPH07115915B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01203262A (en) | 1989-08-16 |
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