JP2916664B2 - Oriented alumina sintered body - Google Patents
Oriented alumina sintered bodyInfo
- Publication number
- JP2916664B2 JP2916664B2 JP6109670A JP10967094A JP2916664B2 JP 2916664 B2 JP2916664 B2 JP 2916664B2 JP 6109670 A JP6109670 A JP 6109670A JP 10967094 A JP10967094 A JP 10967094A JP 2916664 B2 JP2916664 B2 JP 2916664B2
- Authority
- JP
- Japan
- Prior art keywords
- plane
- sintered body
- alumina
- oriented
- crystal
- 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 - Fee Related
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 89
- 239000013078 crystal Substances 0.000 claims description 97
- 238000002441 X-ray diffraction Methods 0.000 claims description 13
- 238000010438 heat treatment Methods 0.000 claims description 12
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 8
- 230000002093 peripheral effect Effects 0.000 claims description 8
- 239000000843 powder Substances 0.000 claims description 7
- 230000001681 protective effect Effects 0.000 claims description 7
- 238000010298 pulverizing process Methods 0.000 claims description 7
- 230000007797 corrosion Effects 0.000 description 26
- 238000005260 corrosion Methods 0.000 description 26
- 239000002245 particle Substances 0.000 description 23
- 239000002994 raw material Substances 0.000 description 13
- 230000035939 shock Effects 0.000 description 11
- 238000000034 method Methods 0.000 description 10
- 230000007423 decrease Effects 0.000 description 8
- 239000011521 glass Substances 0.000 description 4
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 4
- 238000000465 moulding Methods 0.000 description 4
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- 239000006061 abrasive grain Substances 0.000 description 3
- 229910003460 diamond Inorganic materials 0.000 description 3
- 239000010432 diamond Substances 0.000 description 3
- 230000003628 erosive effect Effects 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- -1 aluminum compound Chemical class 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 238000003486 chemical etching Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 229910052602 gypsum Inorganic materials 0.000 description 1
- 239000010440 gypsum Substances 0.000 description 1
- 239000003779 heat-resistant material Substances 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000011226 reinforced ceramic Substances 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Furnace Charging Or Discharging (AREA)
- Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、配向性アルミナ質焼結
体に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oriented alumina sintered body.
【０００２】[0002]
【従来の技術及びその課題】Ａｌ2 Ｏ3 は、耐食性、耐
熱性等に優れ、他のセラミックス材料と比べて安価で取
扱い易いものであることから、高温部材、熱処理用容
器、セッター、炉心管、測温用保護管等の広い分野で使
用されている。2. Description of the Related Art Al 2 O 3 is excellent in corrosion resistance and heat resistance and is inexpensive and easy to handle as compared with other ceramic materials. Therefore, high temperature members, heat treatment vessels, setters, and furnace tubes are required. It is used in a wide range of fields, such as thermometer protection tubes.
【０００３】しかしながら、従来のアルミナ質セラミッ
クスでは、焼結体中に含まれる不純物により結晶粒界で
ガラス相が形成され、このガラス相が高温で軟化するた
めに、強度、クリープ特性等が温度の上昇に伴って低下
し、曲がりや割れが発生しやすいという欠点がある。ま
た、粒界に存在するガラス相は、高温下で、被熱処理物
と反応して耐食性の低下の原因となることもある。However, in conventional alumina ceramics, a glass phase is formed at a crystal grain boundary due to impurities contained in a sintered body, and this glass phase is softened at a high temperature. There is a drawback that it decreases with rising, and that bending or cracking is likely to occur. In addition, the glass phase present at the grain boundary may react with the heat-treated material at a high temperature and cause a reduction in corrosion resistance.
【０００４】このため、アルミナ純度を高くして耐熱
性、耐食性等を向上させることが試みられているが、耐
熱性は従来のアルミナ質焼結体と比べて向上するもの
の、耐食性及び耐熱性を同時に満たすように微構造制御
がなされていないために、耐食性については十分に改善
されるには至っていない。For this reason, attempts have been made to improve the heat resistance, corrosion resistance, etc. by increasing the purity of alumina. However, although the heat resistance is improved as compared with the conventional alumina sintered body, the corrosion resistance and heat resistance are not improved. Since microstructure control has not been performed to satisfy at the same time, corrosion resistance has not been sufficiently improved.
【０００５】[0005]
【課題を解決するための手段】本発明者は、上記した如
き課題に鑑みて、優れた耐食性及び耐熱性を有するアル
ミナ質焼結体を得るべく、鋭意研究を重ねてきた。その
結果、α−Ａｌ2 Ｏ3結晶が、六方晶系の結晶構造を有
し、結晶形状が板状であることに着目し、アルミナ結晶
を一定の条件を満足するように焼成過程で配向させると
共に、アルミナ純度、結晶粒径及び密度について特定の
条件を満足するように制御して得た焼結体は、アルミナ
が本来有する耐食性及び耐熱性を十分に生かして極めて
優れた耐食性及び耐熱性を有する焼結体となることを見
出し、ここに本発明を完成するに至った。Means for Solving the Problems In view of the above-mentioned problems, the present inventors have made intensive studies in order to obtain an alumina sintered body having excellent corrosion resistance and heat resistance. As a result, focusing on the fact that the α-Al 2 O 3 crystal has a hexagonal crystal structure and a plate-like crystal shape, the alumina crystal is oriented in the firing process so as to satisfy certain conditions. At the same time, the sintered body obtained by controlling the alumina purity, the crystal grain size and the density so as to satisfy the specific conditions, fully utilize the inherent corrosion resistance and heat resistance inherent to alumina to achieve extremely excellent corrosion resistance and heat resistance. The present invention was found to be a sintered body having the same, and the present invention was completed here.
【０００６】即ち、本発明は、下記の配向性アルミナ質
焼結体、並びに該焼結体からなる熱処理用容器、セッタ
ー、炉心管及び測温用保護管を提供するものである。That is, the present invention provides the following oriented alumina-based sintered body, and a heat treatment container, a setter, a furnace tube, and a temperature measuring protective tube made of the sintered body.
【０００７】（１）結晶が配向したアルミナ焼結体であ
って、 ｉ）該焼結体におけるアルミナ結晶のｃ面が配向した面
に垂直な面において、Ｘ線回折により測定した下記各結
晶面(1) An alumina sintered body in which crystals are oriented, i) the following crystal planes measured by X-ray diffraction on a plane perpendicular to the plane in which the c-plane of the alumina crystal in the sintered body is oriented
【０００８】[0008]
【化５】 Embedded image
【０００９】の回折強度から下記式From the diffraction intensity of
【００１０】[0010]
【化６】 Embedded image
【００１１】により求めた回折強度比（ＰB ）と、該焼
結体を粉砕した粉体の上記各結晶面の回折強度から下記
式From the diffraction intensity ratio (P B ) obtained by the above and the diffraction intensity of each of the crystal planes of the powder obtained by pulverizing the sintered body, the following formula is obtained.
【００１２】[0012]
【化７】 Embedded image
【００１３】により求めた回折強度比（ＰP ）とから、
下記式From the diffraction intensity ratio (P P ) obtained from
The following formula
【００１４】[0014]
【化８】 Embedded image
【００１５】により求めた配向度（Ｆ）が０．８以上で
あり、 ii) 該焼結体におけるアルミナ結晶のｃ面が配向した面
で測定した平均結晶粒径が２０〜２００μｍであり、該
焼結体におけるアルミナ結晶のｃ面が配向した面に垂直
な面における平均結晶粒子幅がアルミナ結晶のｃ面が配
向した面で測定した平均結晶粒径の０．４倍以下であ
り、 iii)該焼結体のＡｌ2 Ｏ3 含有量が９９．５重量％以上
であり、 iv) 該焼結体のかさ密度が３．７ｇ／ｃｍ3 以上である
ことを特徴とする配向性アルミナ質焼結体。The degree of orientation (F) obtained by the above is 0.8 or more; ii) the average crystal grain size of the alumina crystal in the sintered body is 20 to 200 μm as measured on the plane in which the c-plane is oriented; The average crystal grain width in a plane perpendicular to the plane in which the c-plane of the alumina crystal in the sintered body is oriented is 0.4 times or less the average crystal grain size measured in the plane in which the c-plane of the alumina crystal is oriented; iii) The sintered body has an Al 2 O 3 content of 99.5% by weight or more, and iv) the sintered body has a bulk density of 3.7 g / cm 3 or more. Union.
【００１６】（２）上記（１）に記載の配向性アルミナ
質焼結体からなる熱処理用容器であって、該容器の内面
及び外面がアルミナ結晶のｃ面が配向した面である熱処
理用容器。(2) A heat treatment container comprising the oriented alumina-based sintered body according to the above (1), wherein the inner and outer surfaces of the container are surfaces in which the c-plane of the alumina crystal is oriented. .
【００１７】（３）上記（１）に記載の配向性アルミナ
質焼結体からなり、両面がアルミナ結晶のｃ面が配向し
た面であるセッター。(3) A setter comprising the oriented alumina-based sintered body according to the above (1), wherein both surfaces are surfaces in which the c-plane of the alumina crystal is oriented.
【００１８】（３）上記（１）に記載の配向性アルミナ
質焼結体からなる円筒状の炉心管又は測温用保護管であ
って、円筒の内周面及び外周面がアルミナ結晶のｃ面が
配向した面である炉心管又は測温用保護管。(3) A cylindrical furnace tube or a temperature-measuring protective tube made of the oriented alumina sintered body described in (1) above, wherein the inner and outer peripheral surfaces of the cylinder are made of alumina crystal c. A furnace tube or a temperature measuring protection tube whose surface is oriented.
【００１９】以下に、本発明の配向性アルミナ質焼結体
が満足すべき要件について具体的に説明する。Hereinafter, the requirements that the oriented alumina-based sintered body of the present invention should satisfy will be specifically described.
【００２０】ｉ）結晶が配向したアルミナ焼結体であっ
て、該焼結体におけるアルミナ結晶のｃ面が配向した面
に垂直な面において、Ｘ線回折により測定した下記各結
晶面I) The following crystal planes, which are measured by X-ray diffraction, on an alumina sintered body in which the crystal is oriented, and on a plane perpendicular to the plane in which the c-plane of the alumina crystal in the sintered body is oriented.
【００２１】[0021]
【化９】 Embedded image
【００２２】の回折強度から下記式From the diffraction intensity of
【００２３】[0023]
【化１０】 Embedded image
【００２４】により求めた回折強度比（ＰB ）と、該焼
結体を粉砕した粉体の上記各結晶面の回折強度から下記
式From the diffraction intensity ratio (P B ) obtained by the above and the diffraction intensity of each of the crystal planes of the powder obtained by pulverizing the sintered body, the following formula was obtained.
【００２５】[0025]
【化１１】 Embedded image
【００２６】により求めた回折強度比（ＰP ）とから、
下記式From the diffraction intensity ratio (P P ) obtained from
The following formula
【００２７】[0027]
【化１２】 Embedded image
【００２８】により求めた配向度（Ｆ）が０．８以上で
あること。The degree of orientation (F) obtained by the above is 0.8 or more.
【００２９】本発明の焼結体において、アルミナ結晶の
ｃ面が配向した面とは、アルミナ結晶における（０００
６）面に平行な面であるｃ面が配向した面である。該焼
結体におけるアルミナ結晶のｃ面が配向した面は、次の
ようにして決定することができる。即ち、焼結体におけ
るある表面についてのＸ線回折の結果、及び該焼結体か
ら切り出したその表面に垂直な面についてのＸ線回折の
結果から、該焼結体の表面及びその垂直面のそれぞれに
ついて下記結晶面In the sintered body of the present invention, the plane in which the c-plane of the alumina crystal is oriented is defined as (000) in the alumina crystal.
6) The c-plane, which is a plane parallel to the plane, is the oriented plane. The plane in which the c-plane of the alumina crystal in the sintered body is oriented can be determined as follows. That is, from the result of X-ray diffraction on a surface of the sintered body and the result of X-ray diffraction on a surface perpendicular to the surface cut out from the sintered body, the surface of the sintered body and its vertical surface The following crystal planes for each
【００３０】[0030]
【化１３】 Embedded image
【００３１】の回折強度を求め、これらの値を用いて下
記式The diffraction intensity of
【００３２】[0032]
【化１４】 Embedded image
【００３３】により、それぞれにおける（０００６）面
の回折強度比（Ｐｃ）を算出し、該焼結体の表面におけ
る（０００６）面の回折強度比（Ｐｃ）が、その垂直面
における（０００６）面の回折強度比（Ｐｃ）よりも大
きい値となる面が該焼結体におけるアルミナ結晶のｃ面
が配向した面である。The diffraction intensity ratio (Pc) of the (0006) plane in each case is calculated, and the diffraction intensity ratio (Pc) of the (0006) plane on the surface of the sintered body is calculated as the (0006) plane in the vertical plane. The surface having a value larger than the diffraction intensity ratio (Pc) is the surface in which the c-plane of the alumina crystal in the sintered body is oriented.
【００３４】本発明では、Ｘ線回折における回折強度の
判定の容易さから、アルミナ結晶のｃ面が配向した面に
垂直な面について着目し、この面についてのＸ線回折の
結果から、上記式により求めた配向度（Ｆ）を、焼結体
におけるアルミナ結晶の配向の程度の大きさの評価の基
準として用いる。In the present invention, attention is paid to a plane perpendicular to the plane in which the c-plane of the alumina crystal is oriented, since the diffraction intensity in the X-ray diffraction is easy to determine. Is used as a criterion for evaluating the degree of orientation of the alumina crystal in the sintered body.
【００３５】本発明において、Ｘ線回折は、該焼結体の
表面部分については、この面を研削加工し、ダイヤモン
ド砥粒で鏡面仕上げを行なった後に行ない、この面に垂
直な面については、該焼結体から垂直面を切り出し、こ
の面を研削加工し、ダイヤモンド砥粒で鏡面仕上げを行
なった後に行なう。測定条件は、いずれの面についても
ターゲットとしてＣｕ、モノクロメータを使用し、スリ
ットを０．１５ｍｍ、ダイバースリットを１°に設定し
てスキャニングスピードを３°／分とする。また、該焼
結体を粉砕した粉体については、該焼結体を平均粒径５
μｍ以下となるように粉砕した後、同様の条件でＸ線回
折を行なう。該焼結体のアルミナ結晶のｃ面が配向した
面に垂直な面のＸ線回折パターンの一例を図１に示し、
該焼結体を粉砕した粉体のＸ線回折パターンの一例を図
２に示す。In the present invention, the X-ray diffraction is performed on the surface portion of the sintered body after the surface is ground and mirror-finished with diamond abrasive grains, and on the surface perpendicular to this surface, A vertical surface is cut out from the sintered body, the surface is ground, and the surface is mirror-finished with diamond abrasive grains. The measurement conditions are as follows: Cu and a monochromator are used as targets for any surface, the slit is set to 0.15 mm, the diver slit is set to 1 °, and the scanning speed is set to 3 ° / min. For the powder obtained by pulverizing the sintered body, the sintered body has an average particle size of 5%.
After pulverization to a size of not more than μm, X-ray diffraction is performed under the same conditions. FIG. 1 shows an example of an X-ray diffraction pattern of a plane perpendicular to the plane in which the c-plane of the alumina crystal of the sintered body is oriented,
FIG. 2 shows an example of an X-ray diffraction pattern of the powder obtained by pulverizing the sintered body.
【００３６】本発明では、この様にして該焼結体におけ
るアルミナ結晶のｃ面が配向した面に垂直な面について
測定した回折強度を用いて求めたＰB とＰP から、上記
式により算出した配向度（Ｆ）が、０．８以上であるこ
とが必要であり、０．９以上であることが好ましい。In the present invention, the P B and P P obtained using the diffraction intensity measured on the plane perpendicular to the plane in which the c-plane of the alumina crystal of the sintered body is oriented in the sintered body are calculated according to the above equation. It is necessary that the obtained degree of orientation (F) is 0.8 or more, and preferably 0.9 or more.
【００３７】本発明のアルミナ質焼結体は、アルミナ結
晶がｃ面で配向し、しかも０．８以上という高い配向度
を有することにより、高温での破壊が急激に起こらず、
クラックが配向した結晶面を進展し、クラックの屈曲及
び分岐が起こり、破壊エネルギーが高くなり、その結
果、高い耐熱衝撃性を示すものとなる。また、耐熱材料
としての使用条件である室温−高温−室温の繰り返しに
よる熱疲労抵抗も高くなり、更に、配向度が高いことに
よって、結晶粒径の分布が少なくなり、結晶粒界面積が
小さくなって、耐食性も向上する。In the alumina-based sintered body of the present invention, since the alumina crystal is oriented in the c-plane and has a high degree of orientation of 0.8 or more, breakage at a high temperature does not occur sharply.
The crystal plane in which the cracks are oriented develops, the cracks are bent and branched, and the breaking energy is increased. As a result, high thermal shock resistance is exhibited. In addition, the thermal fatigue resistance due to the repetition of room temperature-high temperature-room temperature, which is a use condition as a heat-resistant material, becomes high. Further, the high degree of orientation reduces the distribution of crystal grain size and reduces the grain boundary area. Therefore, the corrosion resistance is also improved.
【００３８】ii) 該焼結体におけるアルミナ結晶のｃ面
が配向した面で測定した平均結晶粒径が２０〜２００μ
ｍであり、該焼結体におけるアルミナ結晶のｃ面が配向
した面に垂直な面における平均結晶粒子幅がｃ面が配向
した面で測定した平均結晶粒径の０．４倍以下であるこ
と。Ii) The average crystal grain size measured on the plane where the c-plane of the alumina crystal in the sintered body is oriented is 20 to 200 μm.
m, and the average crystal grain width in a plane perpendicular to the plane in which the c-plane of the alumina crystal in the sintered body is oriented is 0.4 times or less the average crystal grain size measured in the plane in which the c-plane is oriented. .
【００３９】本発明では、アルミナ結晶のｃ面が配向し
た面における平均結晶粒径は、上記Ｘ線回折の場合と同
様に、鏡面仕上げを行なった後、硫酸、リン酸等を用い
た化学エッチング、または熱エッチングを施した後、走
査電子顕微鏡にて観察し、インターセプト法により、１
０点平均から求める。算出式としては、Ｄ＝１．５×Ｌ
／ｎ（Ｄ：平均結晶粒径（μｍ）、Ｌ：測定長さ（μ
ｍ）、ｎ：長さＬ当たりの結晶数）を用いる。また、ア
ルミナ結晶のｃ面が配向した面に垂直な面における平均
結晶粒子幅については、該焼結体からアルミナ結晶のｃ
面が配向した面に垂直な面を切り出して、この面につい
て、研削加工、ダイヤモンド砥粒による鏡面仕上げ、及
び上記と同様のエッチングを施した後、走査電子顕微鏡
により観察して求める。平均結晶粒子幅については、ア
ルミナ結晶のｃ面に垂直方向、即ち、結晶幅の方向での
みインターセプト法により求める。算出式は、Ｗ＝Ｌ／
ｎ（Ｗ：平均結晶粒子幅（μｍ）、Ｌ：測定長さ（μ
ｍ）、ｎ：長さＬ当たりの結晶数）とする。In the present invention, the average crystal grain size in the plane in which the c-plane of the alumina crystal is oriented is determined by performing a mirror finish and then performing a chemical etching using sulfuric acid, phosphoric acid, or the like, as in the case of the X-ray diffraction. Or after thermal etching, observation with a scanning electron microscope, and 1
It is determined from the zero point average. The calculation formula is D = 1.5 × L
/ N (D: average crystal grain size (μm), L: measured length (μ
m), n: the number of crystals per length L). The average crystal grain width in a plane perpendicular to the plane in which the c-plane of the alumina crystal is oriented is calculated from the sintered body by the c-crystal of the alumina crystal.
A plane perpendicular to the plane in which the plane is oriented is cut out, and after grinding, mirror finishing with diamond abrasive grains, and etching similar to the above, the surface is determined by observation with a scanning electron microscope. The average crystal grain width is determined by the intercept method only in the direction perpendicular to the c-plane of the alumina crystal, that is, only in the direction of the crystal width. The calculation formula is: W = L /
n (W: average crystal grain width (μm), L: measured length (μ
m), n: the number of crystals per length L).
【００４０】本発明の焼結体では、上記方法で求めたア
ルミナ結晶のｃ面が配向した面の平均結晶粒径が２０〜
２００μｍの範囲にあることが必要であり、３０〜１８
０μｍの範囲にあることが好ましい。この面における平
均結晶粒径が２０μｍを下回ると、高温において変形や
耐熱衝撃性の低下等が起こりやすく、耐熱性の低下を生
じると共に、耐食性も低下するので好ましくない。一
方、平均結晶粒径が２００μｍを上回ると、アルミナ結
晶粒子の結晶面間の熱膨張率の違いにより、マイクロク
ラックが形成されるために熱衝撃抵抗の低下や耐食性の
低下をまねくので好ましくない。In the sintered body of the present invention, the average crystal grain size of the c-plane oriented surface of the alumina crystal obtained by the above method is 20 to
It is necessary to be in the range of 200 μm, and 30 to 18
It is preferably in the range of 0 μm. If the average crystal grain size on this surface is less than 20 μm, deformation and a decrease in thermal shock resistance are likely to occur at high temperatures, which causes a decrease in heat resistance and a decrease in corrosion resistance. On the other hand, if the average crystal grain size exceeds 200 μm, micro-cracks are formed due to the difference in the coefficient of thermal expansion between the crystal faces of the alumina crystal grains, which leads to a decrease in thermal shock resistance and a decrease in corrosion resistance.
【００４１】また、該焼結体では、アルミナ結晶のｃ面
が配向した面に垂直な面における平均結晶粒子幅がｃ面
が配向した面で測定した平均結晶粒径の０．４倍以下で
あることが必要である。この平均結晶粒子幅が０．４倍
を上回ると、アルミナ結晶のｃ面が配向した面の平均結
晶粒径が大き過ぎる場合と同様に、マイクロクラックが
かなり多く生成して耐熱性及び耐食性の低下をきたすの
で好ましくない。In the sintered body, the average crystal grain width in a plane perpendicular to the plane in which the c-plane of the alumina crystal is oriented is 0.4 times or less the average crystal grain size measured in the plane in which the c-plane is oriented. It is necessary to be. When the average crystal grain width exceeds 0.4 times, as in the case where the average crystal grain size of the plane in which the c-plane of the alumina crystal is oriented is too large, a large number of microcracks are generated and heat resistance and corrosion resistance decrease. Is not preferred.
【００４２】iii)該焼結体のＡｌ2 Ｏ3 含有量が９９．
５重量％以上であること。Iii) The sintered body has an Al 2 O 3 content of 99.
5% by weight or more.
【００４３】焼結体中のＡｌ2 Ｏ3 含有量は、９９．５
重量％以上であることが必要であり、９９．７重量％以
上であることが好ましく、かかる範囲の含有量とするこ
とによって、高い耐熱性及び耐食性を有するものとな
る。Ａｌ2 Ｏ3 の含有量が、９９．５重量％を下回る
と、焼結体中の不純物量が増加し、アルミナ結晶以外の
結晶やガラス相がアルミナ結晶粒界に多く生成して、耐
熱性、耐食性等を低下させると共に、結晶成長を抑制し
て配向度の低下をきたし、このために粒界が増加して被
熱処理物と反応しやすくなって耐食性が低下するので好
ましくない。該焼結体中には焼結助材としてＳｉＯ2 、
ＭｇＯ、ＣａＯ等が含まれてもよく、ＳｉＯ2 量は０．
２重量％以下、ＭｇＯ量及びＣａＯ量は各々０．１重量
％以下であることが好ましく、上記は各成分共に０．１
重量％以下であることがより好ましい。The Al 2 O 3 content in the sintered body was 99.5.
It is necessary to be at least 9% by weight, and preferably at least 99.7% by weight. By setting the content in such a range, high heat resistance and corrosion resistance can be obtained. When the content of Al 2 O 3 is less than 99.5% by weight, the amount of impurities in the sintered body increases, and a large amount of crystals and glass phases other than the alumina crystal are formed at the alumina crystal grain boundary, and the heat resistance is increased. In addition, it lowers the corrosion resistance and the like, suppresses crystal growth, and lowers the degree of orientation. As a result, the grain boundaries increase, which is liable to react with the heat-treated material, and the corrosion resistance decreases, which is not preferable. SiO 2 as a sintering aid in the sintered body,
MgO, CaO and the like may be contained, and the amount of SiO 2 is 0.1.
The content of MgO and the content of CaO are preferably 0.1 wt% or less, respectively.
It is more preferable that the content be not more than weight%.
【００４４】iv) 該焼結体のかさ密度が３．７ｇ／ｃｍ
3 以上であること。Iv) The sintered body has a bulk density of 3.7 g / cm.
3 or more.
【００４５】該焼結体のかさ密度は３．７ｇ／ｃｍ3 以
上であることが必要であり、３．８ｇ／ｃｍ3 以上であ
ることが好ましい。かさ密度が３．７ｇ／ｃｍ3 を下回
ると焼結体内部に気孔が多く存在することとなり、気孔
が起点となって高温で変形し易くなって耐熱衝撃性が低
下し、更に、気孔が起点となって、腐食、反応が進行す
るため、耐食性の低下も生じ、割れ等が発生し易くなる
ので好ましくない。The bulk density of the sintered body is required to be 3.7 g / cm 3 or more and 3.8 g / cm 3 or more. If the bulk density is less than 3.7 g / cm 3 , there will be many pores inside the sintered body, the pores will be the starting point, and the pores will be easily deformed at high temperatures, and the thermal shock resistance will be reduced. As a result, the corrosion and the reaction proceed, so that the corrosion resistance is lowered, and cracks and the like are likely to occur, which is not preferable.
【００４６】本発明のアルミナ質焼結体は、上記した
ｉ）〜iv) の全ての条件を同時に満足するものであり、
これにより、耐熱性及び耐食性の両方の特性が良好な焼
結体となる。The alumina-based sintered body of the present invention satisfies all of the above conditions i) to iv) at the same time,
As a result, a sintered body having both excellent heat resistance and corrosion resistance characteristics is obtained.
【００４７】本発明のアルミナ質焼結体は、例えば、以
下の方法により作製することができる。The alumina sintered body of the present invention can be produced, for example, by the following method.
【００４８】アルミナ原料としては、水酸化アルミニウ
ム等のアルミニウム化合物を焼成してα−Ａｌ2 Ｏ3 と
したものを用いることができ、アルミナ純度が９９．８
重量％以上、比表面積が０．５〜２ｍ2 ／ｇ、平均粒子
径が１〜６μｍの板状粒子からなる板状アルミナ原料
と、アルミナ純度が９９．８重量％以上、比表面積が５
〜８ｍ2 ／ｇ、平均粒子径が０．４〜２．０μｍの粒状
物からなる粒状アルミナ原料を組み合わせて用いること
が好ましい。この場合には、板状アルミナ原料及び粒状
アルミナ原料は、例えば、前者：後者＝５：５〜９：１
程度の重量比となるように配合することが好ましい。こ
の様に板状アルミナ原料と粒状アルミナ原料を組み合わ
せて用いることによって、板状粒子が核となって焼結過
程で粒成長が促進され、結晶の配向が進展する。As the alumina raw material, α-Al 2 O 3 obtained by firing an aluminum compound such as aluminum hydroxide can be used, and the alumina purity is 99.8.
Wt.% Or more, a plate-like alumina raw material composed of plate-like particles having a specific surface area of 0.5 to 2 m 2 / g and an average particle diameter of 1 to 6 μm, an alumina purity of 99.8% by weight or more, and a specific surface area of 5
It is preferable to use a combination of granular alumina raw materials consisting of granular materials having a particle size of from 8 to 8 m 2 / g and an average particle diameter of from 0.4 to 2.0 μm. In this case, the plate-like alumina raw material and the granular alumina raw material are, for example, the former: the latter = 5: 5 to 9: 1.
It is preferable to mix them so that the weight ratio becomes about the same. In this way, by using the plate-like alumina raw material and the granular alumina raw material in combination, the plate-like particles serve as nuclei to promote the grain growth in the sintering process and to promote the crystal orientation.
【００４９】本発明の焼結体を得るには、まず、アルミ
ナ原料を水又は有機溶媒中に入れ、ポットミル、アトリ
ッションミル等の粉砕機を用いて、湿式で粉砕、混合、
分散させる。この際に、平均粒子径２μｍ以下、比表面
積２ｍ2 ／ｇ以上となるように、粉砕、混合、分散させ
ることが好ましい。In order to obtain the sintered body of the present invention, first, an alumina raw material is placed in water or an organic solvent, and wet-pulverized and mixed using a pulverizer such as a pot mill or an attrition mill.
Disperse. At this time, it is preferable to pulverize, mix and disperse the particles so that the average particle diameter is 2 μm or less and the specific surface area is 2 m 2 / g or more.
【００５０】次いで、上記方法で調製した粉体を所定の
形状となるように成形する。成形方法としては、板状粒
子が配列しやすい鋳込み成形、テープ成形、押出成形、
射出成形又はホットプレスを採用することが適当であ
り、これらの成形方法を採用することによって、板状粒
子を面方向に配列させることができる。この様にして得
られた成形体を１６００〜１８００℃、好ましくは１６
５０〜１７５０℃程度で焼成することによって、板状粒
子のｃ面が優先的に粒成長するので、本発明の配向性ア
ルミナ質焼結体を得ることができる。焼結温度が１６０
０℃を下回る場合には、粒成長が少なく、結晶の配向が
促進されず、目的とする焼結体を得難いので好ましくな
い。Next, the powder prepared by the above method is formed into a predetermined shape. As the molding method, cast molding, tape molding, extrusion molding, in which plate-like particles are easily arranged,
It is appropriate to employ injection molding or hot pressing. By employing these molding methods, plate-like particles can be arranged in the plane direction. The molded body thus obtained is heated at 1600 to 1800 ° C., preferably at 16 ° C.
By firing at about 50 to 1750 ° C., the c-plane of the plate-like particles grows preferentially, so that the oriented alumina-based sintered body of the present invention can be obtained. Sintering temperature 160
When the temperature is lower than 0 ° C., the grain growth is small, the crystal orientation is not promoted, and it is difficult to obtain a target sintered body, which is not preferable.
【００５１】本発明の焼結体は、耐熱性及び耐食性に優
れた性質を利用して、例えば、熱処理用容器、セッター
等として有効に用いることができる。熱処理用容器とし
て用いる場合には、その形状は特に限定されず、従来用
いられている熱処理用容器と同様の形状とすればよい
が、容器の内面及び外面において、アルミナ結晶のｃ面
が配向していることが必要である。また、セッターとし
て用いる場合には、板状の形状のセッターの両面におい
て、アルミナ結晶のｃ面が配向していることが必要であ
る。これは、熱処理用容器の内面及び外面、或いはセッ
ターの両面において、アルミナ結晶のｃ面が配向してい
ることによって、熱衝撃抵抗を向上でき、更に、被熱処
理物が接する面においてアルミナ結晶のｃ面が配向して
いることによって、高い耐食性を発揮できることによる
ものである。The sintered body of the present invention can be effectively used as, for example, a container for heat treatment, a setter, etc. by utilizing the properties excellent in heat resistance and corrosion resistance. When used as a heat treatment container, the shape is not particularly limited, and may be the same shape as a conventionally used heat treatment container, but the c-plane of the alumina crystal is oriented on the inner surface and the outer surface of the container. It is necessary to be. When used as a setter, the c-plane of the alumina crystal needs to be oriented on both sides of the plate-shaped setter. This is because the c-plane of the alumina crystal is oriented on the inner surface and the outer surface of the heat treatment container or on both surfaces of the setter, so that the thermal shock resistance can be improved. This is because the orientation of the plane enables high corrosion resistance to be exhibited.
【００５２】また、本発明の焼結体は、炉心管又は測温
用保護管としても有効に用いることができる。炉心管と
は、熱処理用チューブ、サポートチューブ、ラジアント
チューブ等として用いる円筒形状部材である。これらの
場合には、円筒形状をした炉心管または測温用保護管の
内周面及び外周面において、アルミナ結晶のｃ面が配向
していることが必要である。この様に、炉内雰囲気に接
する内周面及び外周面においてアルミナ結晶のｃ面が配
向していることにより、耐食性が向上し、同時に炉の昇
温、降温時に管の内周方向に加わる熱応力に対する抵抗
性も増加して、長寿命の炉心管又は測温用保護管とな
る。Further, the sintered body of the present invention can be effectively used as a furnace tube or a protective tube for temperature measurement. The core tube is a cylindrical member used as a heat treatment tube, a support tube, a radiant tube, or the like. In these cases, it is necessary that the c-plane of the alumina crystal be oriented on the inner peripheral surface and the outer peripheral surface of the cylindrical furnace tube or the temperature measuring protection tube. As described above, the c-plane of the alumina crystal is oriented on the inner peripheral surface and the outer peripheral surface that are in contact with the furnace atmosphere, so that the corrosion resistance is improved, and at the same time, the heat applied in the inner peripheral direction of the tube when the temperature of the furnace is increased or decreased. The resistance to stress also increases, resulting in a long-life core tube or temperature-protective protective tube.
【００５３】[0053]
【発明の効果】本発明の配向性アルミナ質焼結体は、下
記の如き優れた性質を有するものである。The oriented alumina-based sintered body of the present invention has the following excellent properties.
【００５４】（１）耐熱衝撃抵抗性に優れているため
に、加熱、冷却の繰り返しに十分に耐えることができ
る。(1) Since it has excellent thermal shock resistance, it can sufficiently withstand repeated heating and cooling.
【００５５】（２）高温特性に優れているために、高温
での変形等が少ない。(2) Due to excellent high-temperature characteristics, deformation at high temperatures and the like are small.
【００５６】（３）耐食性に優れているために、被熱処
理物を汚染せず、被熱処理物中の成分が炉内雰囲気中に
拡散することを防止できる。(3) Because of the excellent corrosion resistance, the object to be heat-treated is not contaminated, and the components in the object to be heat-treated can be prevented from diffusing into the furnace atmosphere.
【００５７】（４）繊維強化セラミックスや複合体など
を生産する場合のような特殊な手法を用いることなく、
通常のセラミックス製造方法で生産できるので、経済的
に非常に有利である。(4) Without using a special technique as in the case of producing fiber-reinforced ceramics or composites,
Since it can be produced by a normal ceramic manufacturing method, it is very economically advantageous.
【００５８】本発明の配向性アルミナ質焼結体は、以上
のように優れた耐熱性及び耐食性を有するものであり、
この様な優れた性質を利用して、熱処理用容器、セッタ
ー、バーナーノズル、炉心管、保護管等の用途に有効に
用いることができる。The oriented alumina sintered body of the present invention has excellent heat resistance and corrosion resistance as described above.
By utilizing such excellent properties, it can be effectively used for applications such as heat treatment containers, setters, burner nozzles, furnace tubes, protective tubes, and the like.
【００５９】[0059]
【実施例】以下、実施例を挙げて本発明を更に詳細に説
明する。EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples.
【００６０】実施例１ アルミナ含有量９９．８８重量％、比表面積１．５ｍ2
／ｇ、平均粒子径３μｍの板状粒子からなるアルミナ原
料、及びアルミナ含有量９９．８９重量％、比表面積６
ｍ2 ／ｇ、平均粒子径０．５μｍの粉状粒子からなるア
ルミナ原料を用い、その他に少量のＳｉＯ2 、ＣａＯ及
びＭｇＯを加えて、下記表１に記載のアルミナ原料比率
及び純度となるように配合した原料を、ポットミル中
で、比表面積３ｍ2 ／ｇ、平均粒子径２μｍ以下となる
ように湿式粉砕した。Example 1 Alumina content: 99.88% by weight, specific surface area: 1.5 m 2
/ G, alumina raw material composed of plate-like particles having an average particle diameter of 3 μm, an alumina content of 99.89% by weight, and a specific surface area of 6
m 2 / g, using an alumina raw material composed of powdery particles having an average particle diameter of 0.5 μm, and adding a small amount of SiO 2 , CaO and MgO to the mixture so that the alumina raw material ratio and purity shown in Table 1 below are obtained. Was wet-pulverized in a pot mill so that the specific surface area was 3 m 2 / g and the average particle diameter was 2 μm or less.
【００６１】次いで、得られたスラリーを石膏型を用い
て鋳込み成形し、表１に示す温度で３時間焼成して、５
０×５０×５ｍｍの角板の焼結体を得た。得られた各焼
結体の特性を表１に示す。Next, the obtained slurry was cast and molded using a gypsum mold, and calcined at the temperature shown in Table 1 for 3 hours.
A sintered body of a square plate of 0 × 50 × 5 mm was obtained. Table 1 shows the characteristics of the obtained sintered bodies.
【００６２】[0062]
【表１】 [Table 1]
【００６３】注） １）板状：粒状＝板状粒子からなるアルミナ原料：粒状
粒子からなるアルミナ原料（重量比） ２）結晶粒径＝アルミナ結晶のｃ面が配向した面で測定
した平均結晶粒径 ３）粒子幅／結晶粒径＝アルミナ結晶のｃ面が配向した
面の平均結晶粒径に対するこの面に垂直な面の平均結晶
粒子幅。Note) 1) Plate: Granular = Alumina raw material composed of plate-like particles: Alumina raw material composed of granular particles (weight ratio) 2) Crystal particle size = Average crystal measured on the c-plane oriented surface of alumina crystal Particle size 3) Particle width / crystal particle size = Average crystal grain width of a plane perpendicular to this plane with respect to the average crystal grain size of the plane in which the c-plane of the alumina crystal is oriented.
【００６４】得られた各焼結体について、下記の方法に
より耐食性及び耐熱衝撃抵抗性の試験を行なった。The obtained sintered bodies were tested for corrosion resistance and thermal shock resistance by the following methods.
【００６５】耐食性試験 各焼結体の上にチタン酸ジルコン酸鉛（ＰＺＴ）成形体
を乗せ、電気炉中で１２５０℃で５時間熱処理した後、
ＰＺＴ成形体の成分であるＰｂＯの侵食深さを測定し
た。尚、侵食深さは、焼結体断面をエネルギー分散形Ｘ
線分析（ＥＤＸ）により分析して決定した。その結果を
下記表２に示す。 Corrosion resistance test A lead zirconate titanate (PZT) compact was placed on each sintered compact and heat-treated at 1250 ° C. for 5 hours in an electric furnace.
The erosion depth of PbO, which is a component of the PZT molded body, was measured. The erosion depth was determined by changing the cross section of the sintered body by the energy dispersive X
Determined by analysis by linear analysis (EDX). The results are shown in Table 2 below.
【００６６】[0066]
【表２】 [Table 2]
【００６７】以上の結果から明らかなように、本発明の
焼結体は、ＰＺＴ成形体中のＰｂＯの侵食深さが２ｍｍ
以下であり、高い耐食性を有するものであった。As is clear from the above results, the sintered body of the present invention has a PbO erosion depth of 2 mm in the PZT molded body.
It was the following and had high corrosion resistance.
【００６８】熱衝撃抵抗性試験 表１の試料Ｎｏ．２、３、６及び７の焼結体について熱
衝撃試験を行なった。試験方法は、１５００℃に加熱保
持した電気炉中に５×５×４５ｍｍの棒状に加工した各
焼結体を入れて２０分間保持した後、室温においた電融
アルミナ（粒度：４０メッシュ以下）中に落下させる方
法とし、この加熱及び室温での落下を１０回繰り返して
割れの発生を調べた。結果を下記表３に示す。 Thermal shock resistance test Sample No. 1 in Table 1 A thermal shock test was performed on 2, 3, 6, and 7 sintered bodies. The test method was as follows. Each sintered body processed into a rod shape of 5 × 5 × 45 mm was placed in an electric furnace heated and held at 1500 ° C., and held for 20 minutes, and then fused alumina at room temperature (particle size: 40 mesh or less). The heating and dropping at room temperature were repeated 10 times, and the occurrence of cracks was examined. The results are shown in Table 3 below.
【００６９】[0069]
【表３】 [Table 3]
【００７０】以上の結果から明らかなように、本発明の
焼結体は、優れた耐熱衝撃性を有するのに対して、本発
明の焼結体に要求される要件を一つでも満たさないもの
は、耐熱衝撃性に劣るものであった。As is apparent from the above results, the sintered body of the present invention has excellent thermal shock resistance, but does not satisfy at least one of the requirements for the sintered body of the present invention. Was inferior in thermal shock resistance.
【図１】本発明焼結体におけるアルミナ結晶のｃ面が配
向した面に垂直な面のＸ線回折パターンを示す図面。FIG. 1 is a drawing showing an X-ray diffraction pattern of a plane perpendicular to a plane in which the c-plane of an alumina crystal in a sintered body of the present invention is oriented.
【図２】本発明焼結体を粉砕した粉体のＸ線回折パター
ンを示す図面。FIG. 2 is a drawing showing an X-ray diffraction pattern of a powder obtained by pulverizing the sintered body of the present invention.
フロントページの続き (72)発明者 河波 利夫 大阪府堺市遠里小野町３丁２番24号 株 式会社ニッカトー内 (56)参考文献 特開 昭64−33055（ＪＰ，Ａ) 特開 平５−270894（ＪＰ，Ａ) 特開 昭55−71697（ＪＰ，Ａ)Continuation of the front page (72) Inventor Toshio Kawanami 3-24, Enri-Ono-cho, Sakai-shi, Osaka Inside Nikkato Co., Ltd. (56) References JP-A-64-33055 (JP, A) 5-270894 (JP, A) JP-A-55-71697 (JP, A)
Claims (4)
に垂直な面において、Ｘ線回折により測定した下記各結
晶面 【化１】 の回折強度から下記式 【化２】 により求めた回折強度比（ＰB ）と、該焼結体を粉砕し
た粉体の上記各結晶面の回折強度から下記式 【化３】 により求めた回折強度比（ＰP ）とから、下記式 【化４】 により求めた配向度（Ｆ）が０．８以上であり、 ii) 該焼結体におけるアルミナ結晶のｃ面が配向した面
で測定した平均結晶粒径が２０〜２００μｍであり、該
焼結体におけるアルミナ結晶のｃ面が配向した面に垂直
な面における平均結晶粒子幅がアルミナ結晶のｃ面が配
向した面で測定した平均結晶粒径の０．４倍以下であ
り、 iii)該焼結体のＡｌ2 Ｏ3 含有量が９９．５重量％以上
であり、 iv) 該焼結体のかさ密度が３．７ｇ／ｃｍ3 以上である
ことを特徴とする配向性アルミナ質焼結体。1. An alumina sintered body in which crystals are oriented, i) a crystal plane measured by X-ray diffraction on a plane perpendicular to the plane in which the c-plane of the alumina crystal in the sintered body is oriented: Formula 1 From the diffraction intensity of From the diffraction intensity ratio (P B ) obtained by the above and the diffraction intensity of each of the crystal planes of the powder obtained by pulverizing the sintered body, the following formula was obtained. From the diffraction intensity ratio (P P ) obtained by the following formula, Ii) the average crystal grain size measured on the plane in which the c-plane of the alumina crystal in the sintered body is oriented is 20 to 200 μm; The average crystal grain width in a plane perpendicular to the plane in which the c-plane of the alumina crystal is oriented is not more than 0.4 times the average crystal grain size measured in the plane in which the c-plane of the alumina crystal is oriented, and iii) An oriented alumina-based sintered body, wherein the sintered body has an Al 2 O 3 content of 99.5% by weight or more, and iv) the bulk density of the sintered body is 3.7 g / cm 3 or more.
からなる熱処理用容器であって、該容器の内面及び外面
がアルミナ結晶のｃ面が配向した面である熱処理用容
器。2. A heat treatment container comprising the oriented alumina-based sintered body according to claim 1, wherein an inner surface and an outer surface of the container are surfaces in which the c-plane of the alumina crystal is oriented.
からなり、両面がアルミナ結晶のｃ面が配向した面であ
るセッター。3. A setter comprising the oriented alumina sintered body according to claim 1, wherein both surfaces are surfaces in which c-planes of alumina crystals are oriented.
からなる円筒状の炉心管又は測温用保護管であって、円
筒の内周面及び外周面がアルミナ結晶のｃ面が配向した
面である炉心管又は測温用保護管。4. A cylindrical furnace tube or a temperature-measuring protective tube made of the oriented alumina-based sintered body according to claim 1, wherein the inner peripheral surface and the outer peripheral surface of the cylinder have alumina crystal c-planes. A furnace tube or temperature-measuring protective tube that is an oriented surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6109670A JP2916664B2 (en) | 1994-05-24 | 1994-05-24 | Oriented alumina sintered body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6109670A JP2916664B2 (en) | 1994-05-24 | 1994-05-24 | Oriented alumina sintered body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07315915A JPH07315915A (en) | 1995-12-05 |
| JP2916664B2 true JP2916664B2 (en) | 1999-07-05 |
Family
ID=14516201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6109670A Expired - Fee Related JP2916664B2 (en) | 1994-05-24 | 1994-05-24 | Oriented alumina sintered body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2916664B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20170088823A (en) | 2014-11-28 | 2017-08-02 | 엔지케이 인슐레이터 엘티디 | Alumina sintered body and ground substrate for optical element |
| US10221076B2 (en) | 2015-09-30 | 2019-03-05 | Ngk Insulators, Ltd. | Method for producing a plate-like alumina power |
| US10343928B2 (en) | 2014-11-28 | 2019-07-09 | Ngk Insulators, Ltd. | Method for manufacturing plate-like alumina powder and plate-like alumina powder |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3783521B2 (en) | 2000-04-20 | 2006-06-07 | 株式会社村田製作所 | Article for heat treatment and method for producing the same |
| US10421681B2 (en) | 2010-07-12 | 2019-09-24 | Corning Incorporated | Alumina isopipes for use with tin-containing glasses |
| JP6982000B2 (en) * | 2016-12-21 | 2021-12-17 | 日本碍子株式会社 | Oriented AlN sintered body and its manufacturing method |
| WO2019189378A1 (en) * | 2018-03-27 | 2019-10-03 | 日本碍子株式会社 | Aluminum nitride sheet |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6433055A (en) * | 1987-07-27 | 1989-02-02 | Sumitomo Cement Co | Sintered body of alumina having high strength and its production |
| JPH05270894A (en) * | 1992-03-27 | 1993-10-19 | Sumitomo Metal Ind Ltd | Ceramic substrate manufacturing method |
-
1994
- 1994-05-24 JP JP6109670A patent/JP2916664B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20170088823A (en) | 2014-11-28 | 2017-08-02 | 엔지케이 인슐레이터 엘티디 | Alumina sintered body and ground substrate for optical element |
| US10138166B2 (en) | 2014-11-28 | 2018-11-27 | Ngk Insulators, Ltd. | Alumina sintered body and base substrate for optical device |
| US10343928B2 (en) | 2014-11-28 | 2019-07-09 | Ngk Insulators, Ltd. | Method for manufacturing plate-like alumina powder and plate-like alumina powder |
| US10221076B2 (en) | 2015-09-30 | 2019-03-05 | Ngk Insulators, Ltd. | Method for producing a plate-like alumina power |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07315915A (en) | 1995-12-05 |
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