JPH07149564A - Heat resistant and electrically conductive ceramic - Google Patents
Heat resistant and electrically conductive ceramicInfo
- Publication number
- JPH07149564A JPH07149564A JP5295346A JP29534693A JPH07149564A JP H07149564 A JPH07149564 A JP H07149564A JP 5295346 A JP5295346 A JP 5295346A JP 29534693 A JP29534693 A JP 29534693A JP H07149564 A JPH07149564 A JP H07149564A
- Authority
- JP
- Japan
- Prior art keywords
- sintered body
- partial pressure
- oxygen partial
- heat
- grain 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.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、８００℃以上の大気中
および加湿水素中などの低酸素分圧下において安定であ
り、高耐熱性と高導電性を有する新規な耐熱導電性セラ
ミックスに関する。このような新規な耐熱導電性セラミ
ックスは、固体電解質型燃料電池部材、発熱体素子、耐
熱電極などの高温導電性材料として有用である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel heat-resistant conductive ceramic which is stable in the air at 800 ° C. or higher and under a low oxygen partial pressure such as in humidified hydrogen and has high heat resistance and high conductivity. Such novel heat-resistant conductive ceramics are useful as high-temperature conductive materials such as solid oxide fuel cell members, heating elements, and heat-resistant electrodes.
【０００２】[0002]
【従来の技術】化学式ＬａＣｒＯ3 で表わされるセラミ
ックスのＬａの一部をＡ（ＡはＣａ及びＳｒの少なくと
も一種を示す）で固溶置換し、同時にＣｒの一部をＭ
（ＭはＣｏ及びＮｉの少なくとも一種を示す）で固溶置
換した化学式Ｌａ1-x Ａx Ｃｒ1-y Ｍy Ｏ3 により表わ
されるセラミックスは、導電性が高く、かつ焼結しやす
いペロブスカイト型結晶構造を有する複合酸化物として
提案されている。2. Description of the Related Art A portion of La of a ceramic represented by the chemical formula LaCrO 3 is solid-solution-substituted with A (A represents at least one of Ca and Sr), and at the same time, a portion of Cr is M.
The ceramic represented by the chemical formula La 1-x A x Cr 1- y My O 3 solid-displaced with (M is at least one of Co and Ni) is a perovskite type which has high conductivity and is easily sintered. It has been proposed as a complex oxide having a crystal structure.
【０００３】しかしながら、このような複合化により緻
密質で高導電性の焼結体が得られたとしても、この様な
焼結体は高温加湿水素中などの低酸素分圧下で長時間使
用すると、導電性や機械的特性が著しく低下し、また焼
結体が変形するなど諸特性の安定性に欠ける点で問題が
あり、各種の高温雰囲気中で安定した状態で長時間使用
可能な実用的材料とは言い難い状態であった。However, even if a dense and highly conductive sintered body is obtained by such composite formation, such a sintered body is not used for a long time under a low oxygen partial pressure such as in high temperature humidified hydrogen. However, there is a problem in that the electrical conductivity and mechanical properties are remarkably deteriorated, and the various properties such as the deformation of the sintered body are lacking in stability. It was hard to say the material.
【０００４】[0004]
【発明が解決しようとする課題】本発明は、高温の大気
中や加湿水素中などの低酸素分圧下において、公知の材
料に比べて安定な耐熱導電性材料を提供することを目的
とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat resistant conductive material which is more stable than known materials under a low oxygen partial pressure such as high temperature atmosphere or humidified hydrogen.
【０００５】[0005]
【課題を解決するための手段】本発明者は、上記のよう
な従来技術の問題点に留意しつつ鋭意研究を重ねた結
果、化学式Ｌａ1-x Ａx Ｃｒ1-y Ｍy Ｏ3 で表わされる
セラミックスに関して、Ａの種類とｘ量及びＭの種類と
ｙ量を特定範囲に制御し、焼結体のかさ密度、平均結晶
粒径、導電率、曲げ強さを適正範囲とすることによっ
て、高温の大気中や加湿水素中などの低酸素分圧下での
導電性と強度を兼ね備え、しかも耐久性が大幅に改善さ
れた焼結体を得ることができることを見出した。本発明
は、このような新規な知見に基づいて完成されたもので
ある。The present inventor has conducted intensive studies while paying attention to the problems of the prior art as described above. As a result, the chemical formula La 1-x A x Cr 1- y My O 3 By controlling the types of A and the amount of x and the types of M and the amount of y with respect to the represented ceramics within a specific range, the bulk density, the average crystal grain size, the electrical conductivity, and the bending strength of the sintered body are controlled within appropriate ranges. It has been found that it is possible to obtain a sintered body that has both conductivity and strength under a low oxygen partial pressure such as in a high temperature atmosphere or humidified hydrogen, and that has a significantly improved durability. The present invention has been completed based on such new findings.
【０００６】即ち、本発明は下記の耐熱導電性セラミッ
クスを提供するものである。That is, the present invention provides the following heat resistant conductive ceramics.
【０００７】１． （１）化学式Ｌａ1-x Ａx Ｃｒ1-y Ｍy Ｏ3 （式中、Ａ
はＣａ及びＳｒの少なくとも一種を示し、０＜ｘ≦０．
２であり、ＭはＣｏ及びＮｉの少なくとも一種を示し、
０＜ｙ＜０．１である）で表わされるペロブスカイト型
結晶構造を有する焼結体であり、（２）焼結体のかさ密
度が理論密度の９２％以上、（３）焼結体の平均結晶粒
径が２〜３０μｍ、（４）１０００℃での酸素分圧が１
０-16 atm となる加湿水素雰囲気中１０００℃における
導電率が１Ｓ／ｃｍ以上、（５）室温曲げ強さが１０ｋ
ｇｆ／ｍｍ2 以上であり、１０００℃での酸素分圧が１
０-16 atm となる加湿水素雰囲気中１０００℃で１０時
間熱処理した後の焼結体の室温曲げ強さが８ｋｇｆ／ｍ
ｍ2 以上であることを特徴とする耐熱導電性セラミック
ス。1. (1) Chemical formula La 1-x A x Cr 1- y My O 3 (wherein A
Represents at least one of Ca and Sr, and 0 <x ≦ 0.
2, M represents at least one of Co and Ni,
0 <y <0.1), which is a sintered body having a perovskite crystal structure represented by (2) the bulk density of the sintered body is 92% or more of the theoretical density, and (3) the average of the sintered bodies. Crystal grain size is 2 to 30 μm, (4) oxygen partial pressure at 1000 ° C. is 1
Conductivity of 1 S / cm or more at 1000 ° C. in a humidified hydrogen atmosphere of 0 −16 atm, (5) Room temperature bending strength of 10 k
gf / mm 2 or more and oxygen partial pressure at 1000 ° C is 1
Room temperature bending strength of the sintered body after heat treatment at 1000 ° C. for 10 hours in a humidified hydrogen atmosphere of 0 −16 atm is 8 kgf / m
A heat-resistant conductive ceramics characterized by having a size of m 2 or more.
【０００８】２．化学式Ｌａ1-x Ａx Ｃｒ1-y Ｍy Ｏ3
で表わされる焼結体であって、０．１２＜ｘ≦０．２、
０．０５≦ｙ＜０．１、且つ０．１５≦ｘ＋ｙ≦０．２
５であり、平均結晶粒径が２〜２０μｍである項１に記
載の耐熱導電性セラミックス。2. Chemical formula La 1-x A x Cr 1- y My O 3
A sintered body represented by the formula: 0.12 <x ≦ 0.2,
0.05 ≦ y <0.1 and 0.15 ≦ x + y ≦ 0.2
Item 5. The heat-resistant conductive ceramics according to Item 1, having an average crystal grain size of 2 to 20 µm.
【０００９】３．化学式Ｌａ1-x Ａx Ｃｒ1-y Ｍy Ｏ3
で表わされる焼結体であって、０＜ｘ≦０．１２、０＜
ｙ≦０．０５、且つ０＜ｘ＋ｙ≦０．１５であり、平均
結晶粒径が２〜３０μｍである項１に記載の耐熱導電性
セラミックス。3. Chemical formula La 1-x A x Cr 1- y My O 3
Which is a sintered body represented by 0 <x ≦ 0.12, 0 <
Item 2. The heat-resistant conductive ceramic according to Item 1, wherein y ≦ 0.05 and 0 <x + y ≦ 0.15, and the average crystal grain size is 2 to 30 μm.
【００１０】４．化学式Ｌａ1-x Ａx Ｃｒ1-y Ｍy Ｏ3
で表わされる焼結体のＬａの５０モル％以下をイットリ
ウム及び原子番号５８から７１の希土類元素の少なくと
も一種で置換したものである項１乃至項３のいずれかに
記載の耐熱導電性セラミックス。4. Chemical formula La 1-x A x Cr 1- y My O 3
Item 5. The heat resistant conductive ceramic according to any one of Items 1 to 3, wherein 50 mol% or less of La of the sintered body represented by is substituted with at least one of yttrium and a rare earth element having an atomic number of 58 to 71.
【００１１】以下に、本発明の耐熱導電性セラミックス
が満足すべき（１）〜（５）の要件について詳細に説明
する。The requirements (1) to (5) to be satisfied by the heat resistant conductive ceramics of the present invention will be described in detail below.
【００１２】（１）化学式Ｌａ1-x Ａx Ｃｒ1-y Ｍy Ｏ
3 （式中、ＡはＣａ及びＳｒの少なくとも一種を示し、
０＜ｘ≦０．２であり、ＭはＣｏ及びＮｉの少なくとも
一種を示し、０＜ｙ＜０．１である。）で表わされる組
成を有し、ペロブスカイト型結晶構造であること。(1) Chemical formula La 1-x A x Cr 1- y My O
3 (In the formula, A represents at least one of Ca and Sr,
0 <x ≦ 0.2, M represents at least one of Co and Ni, and 0 <y <0.1. ), And a perovskite type crystal structure.
【００１３】本発明の耐熱導電性セラミックスは、導電
性の点からは、ＬａＣｒＯ3 を基本組成とし、Ｌａの一
部をＣａ及びＳｒ（以下この両者をまとめてＡと記すこ
とがある）の少なくとも一種で固溶置換し、Ｃｒの一部
をＣｏ及びＮｉ（以下これらをまとめてＭと記すことが
ある）の少なくとも一種で固溶置換したものであり、ペ
ロブスカイト型結晶構造を有するものであることが必要
である。この様なセラミックスは、３価のＬａの一部を
２価のＡで固溶置換することによって生じる正の電荷の
不足分をＣｒの３価から一部４価への原子価移動により
補う構造となる。その結果、隣接するＣｒイオンの３価
と４価との間に電子の速やかな移動が生じて導電性が大
幅に向上し、優れた導電性を示すものとなり、また耐熱
性も良好である。From the viewpoint of conductivity, the heat-resistant conductive ceramics of the present invention have LaCrO 3 as a basic composition, and a part of La contains at least Ca and Sr (hereinafter, both may be collectively referred to as A). Solid solution substitution with one type, and part of Cr with solid solution substitution with at least one of Co and Ni (hereinafter collectively referred to as M), and having a perovskite type crystal structure. is necessary. Such a ceramic has a structure in which a shortage of positive charges caused by solid solution substitution of a part of trivalent La with divalent A is compensated by valence transfer of Cr from trivalent to part tetravalent. Becomes As a result, electrons rapidly move between trivalent and tetravalent Cr ions adjacent to each other, conductivity is greatly improved, excellent conductivity is exhibited, and heat resistance is also good.
【００１４】更に、低酸素分圧下における耐熱性の点か
らは上記化学式のｘの値がモル比で０＜ｘ≦０．２であ
り、ｙの値がモル比で０＜ｙ＜０．１であることが必要
である。（ＬａＡ）（ＣｒＭ）Ｏ3 焼結体を高温の低酸
素分圧下にさらした場合、焼結体から酸素イオンが系外
に抜け出た後に酸素空格子が生成する。酸素空格子は、
陽イオンとの間に引力作用が働かないので、酸素空格子
数が増え過ぎると、陽イオンと酸素イオンの間に働く引
力作用の総和が小さくなり、逆に異種の陽イオン間の斥
力作用が強く現れ、結晶格子間の拡張が生じて、焼結体
が伸張するものと考えられ、このことが低酸素分圧下で
の諸特性の安定性を左右する一因でもあると推定され
る。本発明者の研究によれば、このような焼結体の挙動
は上記化学式の中のＡの種類とｘ量及びＭの種類とｙ量
に大きく依存するものであることが明らかとなり、ｘの
許容範囲はモル比で０＜ｘ≦０．２であり、ｙの許容範
囲はモル比で０＜ｙ＜０．１である。Further, from the viewpoint of heat resistance under low oxygen partial pressure, the value of x in the above chemical formula is 0 <x ≦ 0.2 in a molar ratio, and the value of y is 0 <y <0.1 in a molar ratio. It is necessary to be. When the (LaA) (CrM) O 3 sintered body is exposed to high temperature and low oxygen partial pressure, oxygen vacancies are formed after oxygen ions escape from the sintered body. The oxygen vacancies are
Since the attractive force does not work with cations, if the number of oxygen vacancies increases too much, the total attractive force between cations and oxygen ions will decrease, and on the contrary, the repulsive force between different cations will decrease. It is considered that it appears strongly, expansion of the crystal lattice occurs, and the sintered body expands. This is also considered to be one of the factors that influence the stability of various properties under a low oxygen partial pressure. According to the research conducted by the present inventor, it has become clear that the behavior of such a sintered body largely depends on the type of A and the amount of x and the type of M and the amount of y in the above chemical formula. The allowable range is 0 <x ≦ 0.2 in molar ratio, and the allowable range of y is 0 <y <0.1 in molar ratio.
【００１５】また、上記の組成において、Ｌａの５０モ
ル％以下をイットリウム及び原子番号５８から７１の希
土類元素の少なくとも一種（複数元素でも可）で固溶置
換してもよく、この様な組成の焼結体も優れた焼結性を
示し、耐熱性と導電性の著しい低下も認められない。元
素源としては、酸化物、水酸化物、炭酸塩、硝酸塩ある
いは金属アルコキシドなどセラミックス製造に通常使用
される化合物が使用され、化合物の種類やその形態は、
特に限定されない。In the above composition, 50 mol% or less of La may be solid-solution-substituted with yttrium and at least one rare earth element having atomic numbers 58 to 71 (a plurality of elements may be used). The sintered body also exhibits excellent sinterability, and no remarkable decrease in heat resistance and conductivity is observed. As the element source, compounds usually used in the production of ceramics such as oxides, hydroxides, carbonates, nitrates or metal alkoxides are used.
There is no particular limitation.
【００１６】（２）焼結体のかさ密度は理論密度の９２
％以上とする。(2) The bulk density of the sintered body is 92 which is the theoretical density.
% Or more.
【００１７】かさ密度が理論密度の９２％未満では、気
孔量の増加により、導電性、気密性、機械的強度等が著
しく低下する。従って、かさ密度は理論密度の９２％以
上であることが必要であり、９３％以上であることが好
ましく、固体電解質型燃料電池のセパレータのように、
使用時に材料の片側が高温の空気等の高酸素分圧下にさ
らされ、他の片側が高温の水素等の低酸素分圧下にさら
される場合には、水素ガスに対する気密性を維持するた
めに、かさ密度は理論密度の９４％以上であることが更
に好ましい。When the bulk density is less than 92% of the theoretical density, the conductivity, airtightness, mechanical strength, etc. are remarkably lowered due to the increase in the amount of pores. Therefore, the bulk density needs to be 92% or more of the theoretical density, and is preferably 93% or more, like the separator of the solid oxide fuel cell.
When one side of the material is exposed to high oxygen partial pressure such as hot air during use, and the other side is exposed to low oxygen partial pressure such as high temperature hydrogen, in order to maintain airtightness against hydrogen gas, The bulk density is more preferably 94% or more of the theoretical density.
【００１８】（３）焼結体の平均結晶粒径は、２〜３０
μｍとする。(3) The average crystal grain size of the sintered body is 2 to 30.
μm.
【００１９】本発明者の研究によれば、高温の低酸素下
での強度やその他の特性は、焼結体の結晶粒径の影響を
大きく受けるために、焼結体の平均結晶粒径を２〜３０
μｍの範囲とすることが必要であることが明らかとなっ
た。焼結体の平均結晶粒径が２μｍ未満の場合には、高
温で応力がかかった際に、機械的特性、特に強度及び耐
クリープ性が低下して高温での使用時の耐久性が不十分
となり、また高温で水蒸気が存在する雰囲気下で使用す
る際の安定性及び耐久性が劣化し、更に、本発明焼結体
を固体電解質型燃料電池のセパレーターとして使用する
場合に、焼結体と接触するランタンマンガネート系酸化
物、ニッケルサーメットなどとの反応が生じやすくなる
ので好ましくない。一方、焼結体の平均結晶粒径が３０
μｍを上回る場合には、耐クリープ性は良好となるが、
機械的強度、特に高温の低酸素分圧下に長時間さらされ
た場合の強度が低下するために好ましくない。この様に
高温の低酸素下での強度が焼結体の結晶粒径の影響を受
ける原因は明らかではないが、結晶粒径が大きくなるに
従って、結晶粒成長過程において粒内や粒界に空孔が生
じ易くなることや、粒内や粒界の組成の不均質化が生じ
易くなること等に起因しているものと推考される。According to the research conducted by the present inventor, the strength and other characteristics under high temperature and low oxygen are greatly influenced by the crystal grain size of the sintered body. 2-30
It has become clear that it is necessary to set the thickness in the range of μm. When the average crystal grain size of the sintered body is less than 2 μm, mechanical properties, especially strength and creep resistance are deteriorated when stress is applied at high temperature, resulting in insufficient durability when used at high temperature. In addition, the stability and durability when used in an atmosphere where water vapor is present at high temperature deteriorates, and when the sintered body of the present invention is used as a separator of a solid oxide fuel cell, It is not preferable because reaction with the lanthanum manganate-based oxide, nickel cermet, etc. that come into contact with each other easily occurs. On the other hand, the average crystal grain size of the sintered body is 30
If it exceeds μm, the creep resistance is good, but
It is not preferable because the mechanical strength, especially the strength when exposed to a high temperature and low oxygen partial pressure for a long time, decreases. The cause of the influence of the grain size of the sintered body on the strength under high temperature and low oxygen is not clear, but as the grain size increases, voids are formed in the grains and grain boundaries during the grain growth process. It is presumed that this is due to the fact that pores are likely to occur and that the composition within the grains and the grain boundaries is likely to become inhomogeneous.
【００２０】また、焼結体の平均結晶粒径の好ましい範
囲は、焼結体の化学組成の影響を受け、上記化学式にお
いて、０．１２＜ｘ≦０．２、０．０５≦ｙ＜０．１、
且つ０．１５≦ｘ＋ｙ≦０．２５の場合には平均結晶粒
径が２〜２０μｍであることが好ましく、０＜ｘ≦０．
１２、０＜ｙ≦０．０５、且つ０＜ｘ＋ｙ≦０．１５の
場合には平均結晶粒径が２〜３０μｍであることが好ま
しい。この様に、焼結体の平均結晶粒径の好ましい範囲
が、化学組成の影響を受ける理由は、前述したように、
高温の低酸素下での強度は、平均結晶粒径の他に、高温
の低酸素下での結晶格子の伸張の影響を受け、結晶格子
の伸張は焼結体の組成に大きく依存するために、焼結体
を高温の低酸素下で高強度とするためには、焼結体の化
学組成と平均結晶粒径との間に一定の関係が生じるから
であると考えられる。尚、焼結体の伸張が強度に影響す
ることについては、焼結体の伸張が大きいほどマイクロ
クラックが生じ易くなること等に起因するものと考えら
れる。The preferable range of the average crystal grain size of the sintered body is influenced by the chemical composition of the sintered body, and in the above chemical formula, 0.12 <x ≦ 0.2 and 0.05 ≦ y <0. .1,
When 0.15 ≦ x + y ≦ 0.25, the average crystal grain size is preferably 2 to 20 μm, and 0 <x ≦ 0.
When 12, 0 <y ≦ 0.05 and 0 <x + y ≦ 0.15, the average crystal grain size is preferably 2 to 30 μm. As described above, the reason why the preferable range of the average crystal grain size of the sintered body is affected by the chemical composition is as follows.
The strength under high temperature and low oxygen is affected by the extension of the crystal lattice under high temperature and low oxygen in addition to the average crystal grain size, and the extension of the crystal lattice greatly depends on the composition of the sintered body. In order to make the sintered body have high strength under high temperature and low oxygen, it is considered that a certain relationship is generated between the chemical composition of the sintered body and the average crystal grain size. It is considered that the elongation of the sintered body affects the strength because the larger the elongation of the sintered body, the more easily microcracks are generated.
【００２１】本発明において、焼結体の平均結晶粒径の
測定方法は、焼結体表面を鏡面にまで研磨し、熱エッチ
ングまたは化学エッチングした後、走査電子顕微鏡で観
察してインターセプト法により、１０点の平均値から求
める。算出式は、Ｄ＝１．５×ｎ／Ｌである（但し、Ｌ
は測定長さ、Ｄは平均結晶粒径、ｎは長さＬ当たりの結
晶の数である。）。In the present invention, the average crystal grain size of the sintered body is measured by polishing the surface of the sintered body to a mirror surface, thermal etching or chemical etching, and then observing with a scanning electron microscope to determine by an intercept method. Obtained from the average value of 10 points. The calculation formula is D = 1.5 × n / L (where L is
Is the measured length, D is the average crystal grain size, and n is the number of crystals per length L. ).
【００２２】（４）１０００℃での酸素分圧が１０-16
atm となる加湿水素雰囲気中１０００℃における導電率
は１Ｓ／ｃｍ以上とする。(4) The oxygen partial pressure at 1000 ° C. is 10 -16
The electrical conductivity at 1000 ° C. in a humidified hydrogen atmosphere of atm is 1 S / cm or more.
【００２３】本セラミックスが固体電解質型燃料電池の
セパレータとして使用される場合には、低酸素分圧下に
さらされる側の導電率は、主として４価Ｃｒの３価Ｃｒ
への還元により低下すので、低酸素分圧下において良好
な導電率を維持することが必要である。よって、１００
０℃での酸素分圧が１０-16 atm となる加湿水素雰囲気
中１０００℃における導電率は１Ｓ／ｃｍ以上であるこ
とが必要であり、２Ｓ／ｃｍ以上であることが好まし
い。When the present ceramic is used as a separator for a solid oxide fuel cell, the conductivity on the side exposed to low oxygen partial pressure is mainly trivalent Cr, which is tetravalent Cr.
It is necessary to maintain a good conductivity under a low oxygen partial pressure, since it is reduced by the reduction to. Therefore, 100
The electrical conductivity at 1000 ° C. in a humidified hydrogen atmosphere where the oxygen partial pressure at 0 ° C. is 10 −16 atm must be 1 S / cm or more, and preferably 2 S / cm or more.
【００２４】（５）室温曲げ強さが１０ｋｇｆ／ｍｍ2
以上であり、１０００℃での酸素分圧が１０-16 atm と
なる加湿水素雰囲気中１０００℃で１０時間熱処理した
後の焼結体の室温曲げ強さが８ｋｇｆ／ｍｍ2 以上であ
ること。(5) Room temperature bending strength is 10 kgf / mm 2
Above, the room temperature bending strength of the sintered body after heat treatment at 1000 ° C. for 10 hours in a humidified hydrogen atmosphere where the oxygen partial pressure at 1000 ° C. is 10 −16 atm is 8 kgf / mm 2 or more.
【００２５】本発明のセラミックスは、例えば、固体電
解質型燃料電池部材、発熱体素子、耐熱電極などの高温
導電性材料として使用されるものであり、十分な強度を
有するために焼結体の室温曲げ強さが１０ｋｇｆ／ｍｍ
2 以上であることが必要であり、１５ｋｇｆ／ｍｍ2 以
上であることが好ましい。The ceramic of the present invention is used as a high temperature conductive material such as a solid oxide fuel cell member, a heating element, and a heat resistant electrode. Bending strength is 10 kgf / mm
Must be at least two, it is preferably 15 kgf / mm 2 or more.
【００２６】また、この焼結体を、固体電解質型燃料電
池のセパレータのように使用時に材料が高温の加湿水素
等の低酸素分圧下にさらされるような用途に用いる場合
には、この様な雰囲気下でも十分な強度を有する必要が
あり、この焼結体を１０００℃での酸素分圧が１０-16
atm となる加湿水素雰囲気中１０００℃で１０時間還元
処理した後の室温曲げ強さは８ｋｇｆ／ｍｍ2 以上であ
ることが必要であり、１０ｋｇｆ／ｍｍ2 以上であるこ
とが好ましい。When the sintered body is used for applications such as a separator of a solid oxide fuel cell in which the material is exposed to a low oxygen partial pressure such as high temperature humidified hydrogen at the time of use, it is possible to obtain It is necessary that the sintered body has sufficient strength even in an atmosphere, and the oxygen partial pressure at 1000 ° C. of this sintered body is 10 −16.
The room temperature bending strength after reduction treatment at 1000 ° C. for 10 hours in a humidified hydrogen atmosphere of atm is required to be 8 kgf / mm 2 or more, and preferably 10 kgf / mm 2 or more.
【００２７】尚、還元処理後の室温曲げ強さは、上述の
通り、焼結体の平均結晶粒径と還元処理後の焼結体の伸
張にも依存しており、還元処理後も十分な強度を保つた
めには、焼結体の組成、平均結晶粒径等を上記範囲内に
すると共に、焼結体に含有される６価Ｃｒ量が１．５重
量％以下であることが望ましい。The room-temperature bending strength after the reduction treatment depends on the average crystal grain size of the sintered body and the elongation of the sintered body after the reduction treatment as described above, and is sufficient even after the reduction treatment. In order to maintain the strength, it is desirable that the composition of the sintered body, the average crystal grain size, etc. be within the above ranges and the amount of hexavalent Cr contained in the sintered body be 1.5% by weight or less.
【００２８】また、本発明の焼結体は、導電性及び耐久
性の観点からは、焼結助剤としてのアルカリ金属酸化物
及びＳｉＯ2 の含有量はそれぞれ０．２重量％以下、Ａ
ｌ2Ｏ3 の含有量は０．３重量％以下であることが好ま
しい。From the viewpoint of conductivity and durability, the sintered body of the present invention has an alkali metal oxide content of SiO 2 and a SiO 2 content of 0.2 wt% or less, respectively, as a sintering aid, and A
The content of l 2 O 3 is preferably 0.3% by weight or less.
【００２９】本発明による焼結体は、通常以下のように
して製造される。The sintered body according to the present invention is usually manufactured as follows.
【００３０】まず、焼結体を構成する各成分の原料（Ｌ
ａ源、Ａ源、Ｃｒ源及びＭ源）を所定の割合に配合し、
必要に応じて、焼結助剤としてのアルカリ金属酸化物、
ＳｉＯ2 、Ａｌ2 Ｏ3 を含有させて均一に混合、分散し
て、粉末混合物を得る。各原料としては、酸化物、水酸
化物、炭酸塩、硝酸塩、金属アルコキシド等を使用でき
る。粉末の粒度は特に限定されないが、通常は１０μｍ
以下程度とすることが望ましい。なお、Ｃｒ源には６価
Ｃｒ量の少ない原料を使用することが望ましい。混合
は、粉末の湿式混合又は乾式混合のいずれの方法によっ
ても良く、また、各元素を含む水溶液などの混合でも良
い。尚、湿式混合の場合は有機溶媒を使用することが好
ましく、水を使用する場合にはアルカリ成分やＳｉＯ2
分などの含有量が上記範囲を上回らないようにイオン交
換水若しくは蒸留水を使用することが望ましい。First, the raw materials (L
a source, A source, Cr source and M source) in a predetermined ratio,
If necessary, an alkali metal oxide as a sintering aid,
SiO 2 and Al 2 O 3 are contained and uniformly mixed and dispersed to obtain a powder mixture. As each raw material, oxides, hydroxides, carbonates, nitrates, metal alkoxides and the like can be used. The particle size of the powder is not particularly limited, but usually 10 μm
It is desirable to set it to about In addition, it is desirable to use a raw material having a small amount of hexavalent Cr for the Cr source. The mixing may be either a wet mixing method or a dry mixing method of powders, or may be an aqueous solution containing each element. In the case of wet mixing, it is preferable to use an organic solvent, and when water is used, an alkaline component or SiO 2 is used.
It is desirable to use ion-exchanged water or distilled water so that the content such as the minutes does not exceed the above range.
【００３１】次いで、上記で得られた粉末混合物を、そ
の７０％以上がペロブスカイト型結晶構造となる温度以
上で熱処理し、合成粉末とする。合成温度は通常８００
〜１４００℃程度の範囲にあり、より好ましくは９００
〜１３５０℃程度の範囲にある。合成時間は合成温度と
も関係するが、通常０．５〜１０時間程度である。合成
雰囲気は大気中など酸素含有雰囲気が好ましい。更にこ
の合成粉末を粉砕後、上記の熱処理を数回繰返して組成
の均一化を図ることが望ましい。Next, the powder mixture obtained above is heat-treated at a temperature at which 70% or more of the powder mixture has a perovskite type crystal structure or higher to obtain a synthetic powder. Synthesis temperature is usually 800
Is in the range of about 1400 ° C, more preferably 900
It is in the range of about 1350 ° C. Although the synthesis time is related to the synthesis temperature, it is usually about 0.5 to 10 hours. The synthesis atmosphere is preferably an oxygen-containing atmosphere such as air. Further, after crushing this synthetic powder, it is desirable to repeat the above heat treatment several times to make the composition uniform.
【００３２】次いで、上記で得られた合成粉末を粉砕、
分散する。この工程は前記混合処理と同様に有機溶剤の
存在下で行なうことが好ましいが、水の存在下で行なう
場合には、アルカリ成分やＳｉＯ2 分などの含有量が上
記範囲を上回ることがないように、イオン交換水若しく
は蒸留水を用いることが望ましい。粉砕、分散後の合成
粉末は、平均粒径が３μｍ以下で比表面積が２ｍ2 ／ｇ
以上とすることが好ましく、平均粒径が１μｍ以下で比
表面積が３ｍ2 ／ｇ以上とすることがより好ましい。こ
の粉砕により、焼結体中の組成と構成粒子径の均一化が
実現できる。Next, the synthetic powder obtained above is crushed,
Spread. This step is preferably carried out in the presence of an organic solvent as in the case of the above-mentioned mixing treatment, but when carried out in the presence of water, the contents of alkali components, SiO 2 content, etc. should not exceed the above range. It is desirable to use ion exchanged water or distilled water. The crushed and dispersed synthetic powder has an average particle size of 3 μm or less and a specific surface area of 2 m 2 / g.
The average particle diameter is preferably 1 μm or less and the specific surface area is more preferably 3 m 2 / g or more. By this pulverization, it is possible to realize uniform composition and constituent particle diameter in the sintered body.
【００３３】次いで、所定の粒度に粉砕された粉末をプ
レス成形、ＣＩＰ成形、鋳込み成形、テープ成形、押し
出し成形、ホットプレス成形等のセラミックス成形の常
法により成形する。この際、アクリル系など公知の成形
助剤を適当量添加しても良いことは言うまでもない。Then, the powder pulverized to a predetermined particle size is molded by a usual method of ceramics molding such as press molding, CIP molding, cast molding, tape molding, extrusion molding, hot press molding and the like. At this time, needless to say, a known molding aid such as acrylic may be added in an appropriate amount.
【００３４】次いで、得られた成形体を焼成する。焼成
雰囲気は減圧、常圧及び加圧のいずれであっても良い。
焼成温度は通常１５００〜１９００℃程度の範囲とし、
好ましくは１６００〜１８００℃程度の範囲とする。
尚、具体的な焼成温度、保持時間等は、焼結体のかさ密
度、平均結晶粒径等の特性値が要求される範囲となるよ
うに適宜設定すればよい。Then, the obtained molded body is fired. The firing atmosphere may be any of reduced pressure, normal pressure and increased pressure.
The firing temperature is usually in the range of 1500 to 1900 ° C,
The temperature is preferably in the range of about 1600 to 1800 ° C.
Incidentally, the specific firing temperature, holding time, etc. may be appropriately set so that the characteristic values such as the bulk density and average crystal grain size of the sintered body fall within the required range.
【００３５】尚、加圧焼結の場合には、より低温で焼結
体を緻密化させることができる。また、Ａ及びＭ成分が
少ない場合には、焼成温度を高める必要がある。低酸素
分圧下で焼成した焼結体は導電性が低下しているので、
この焼結体を大気中１０００℃以上の温度で熱処理する
ことにより、導電性の向上を図ることが望ましい。この
熱処理は必ずしも前記の焼成工程に引き続いて行う必要
はなく、上記の条件を充足する限り、焼結体の使用過程
において行っても良い。In the case of pressure sintering, the sintered body can be densified at a lower temperature. When the A and M components are small, it is necessary to raise the firing temperature. Since the sintered body sintered under low oxygen partial pressure has reduced conductivity,
It is desirable to improve the conductivity by heat-treating this sintered body at a temperature of 1000 ° C. or higher in the atmosphere. This heat treatment does not necessarily have to be performed subsequent to the firing step, and may be performed in the process of using the sintered body as long as the above conditions are satisfied.
【００３６】[0036]
【発明の効果】本発明によれば、下記のような顕著な効
果が達成される。According to the present invention, the following remarkable effects are achieved.
【００３７】（１）焼結体の耐熱性、導電性及びかさ密
度を従来技術では達成できなかった程度まで高めること
ができる。(1) The heat resistance, conductivity, and bulk density of the sintered body can be increased to a level that cannot be achieved by the prior art.
【００３８】（２）特に高温の低酸素分圧下に長時間さ
らされても強度低下、導電率低下が少ない焼結体が得ら
れ、酸素分圧の異なる条件下で焼結体を使用しても伸び
などの変形が少なく、破壊等が生じず耐久性に優れたも
のとなる。(2) In particular, even if the sintered body is exposed to a high temperature and a low oxygen partial pressure for a long time, a sintered body having a reduced strength and a reduced conductivity is obtained, and the sintered body is used under different oxygen partial pressures. Also, there is little deformation such as elongation, breakage does not occur, and the durability is excellent.
【００３９】（３）本発明による焼結体は、水蒸気が存
在する酸化性あるいは還元性雰囲気においても気密性を
保持し、かつ導電性、機械的強度及び形状安定性を長時
間維持できるので、固体電解質型燃料電池のセパレータ
やインターコネクター、発熱体素子、耐熱電極などの実
用材料として有用である。(3) Since the sintered body according to the present invention maintains airtightness even in an oxidizing or reducing atmosphere in which water vapor exists, and can maintain electrical conductivity, mechanical strength and shape stability for a long time. It is useful as a practical material for separators, interconnectors, heating elements, heat-resistant electrodes, etc. of solid oxide fuel cells.
【００４０】[0040]
【実施例】以下に実施例及び比較例を示し、本発明の特
徴とするところを更に明確にする。EXAMPLES Examples and comparative examples will be shown below to further clarify the features of the present invention.
【００４１】実施例１〜７ 表１に示す各組成式の配合となるように、原料粉末を秤
量、配合し、アルコール存在下で湿式で混合、分散を行
った後、乾燥し、大気中１２７０℃で５時間加熱して、
９５％以上がペロブスカイト型構造に合成された粉末を
得た。尚、原料粉末は、組成式に応じて、純度９９．５
％以上のＬａ2 Ｏ3 、ＳｒＣＯ3 、ＣａＣＯ3 、Ｃｒ2
Ｏ3 、ＣｏＯ及びＮｉＯの各酸化物及び炭酸塩から選択
して用いた。得られた合成粉末を媒体攪拌ミルによりア
ルミナ製メディアを用いてアルコール存在下で１２時間
湿式で粉砕、分散し、平均粒径０．６μｍのスラリーを
得た。次いで、これに成形助剤を加えた後、スプレード
ライヤーにより成形用顆粒粉体（平均粒径６０μｍ）を
調製した。この顆粒粉体を成形圧力３ｔｏｎ／ｃｍ2 で
ＣＩＰ成形し、１２０×１２０×４ｍｍの成形体を得た
後、大気中において、表１に記載の温度で４時間焼成し
た。得られた焼結体をダイアモンド砥石により研削加工
して表面を仕上げた試料について特性を測定した。作製
した実施例１〜７の各試料の組成式と焼成温度を表１に
示し、上記した方法で得られた焼結体について測定した
特性を表２に示す。尚、導電率は、１０００℃での酸素
分圧が１０-16 atm となる加湿水素雰囲気中１０００℃
において測定した値であり、曲げ強さは１０００℃での
酸素分圧が１０-16 atm となる加湿水素雰囲気中１００
０℃で１０時間熱処理を行ない、熱処理の前後において
室温で測定した値である。Examples 1 to 7 Raw material powders were weighed and blended so as to have the composition formulas shown in Table 1, wet-mixed and dispersed in the presence of alcohol, dried, and then dried in air 1270. Heat at ℃ for 5 hours,
A powder was obtained in which 95% or more was synthesized in a perovskite structure. The raw material powder has a purity of 99.5 according to the composition formula.
% Or more of La 2 O 3 , SrCO 3 , CaCO 3 , Cr 2
The oxides and carbonates of O 3 , CoO and NiO were selected and used. The obtained synthetic powder was wet pulverized and dispersed for 12 hours in the presence of alcohol using an alumina medium with a medium stirring mill to obtain a slurry having an average particle size of 0.6 μm. Next, a molding aid was added thereto, and then a granule powder for molding (average particle size 60 μm) was prepared by a spray dryer. This granular powder was subjected to CIP molding at a molding pressure of 3 ton / cm 2 to obtain a molded body of 120 × 120 × 4 mm, which was then calcined in the atmosphere at the temperature shown in Table 1 for 4 hours. The characteristics of a sample whose surface was finished by grinding the obtained sintered body with a diamond grindstone were measured. The composition formulas and firing temperatures of the produced samples of Examples 1 to 7 are shown in Table 1, and the properties measured for the sintered bodies obtained by the above-described method are shown in Table 2. The conductivity is 1000 ° C in a humidified hydrogen atmosphere where the oxygen partial pressure at 1000 ° C is 10 -16 atm.
The bending strength is 100 in a humidified hydrogen atmosphere at an oxygen partial pressure of 10 -16 atm at 1000 ° C.
It is a value obtained by performing heat treatment at 0 ° C. for 10 hours and measuring at room temperature before and after the heat treatment.
【００４２】また、実施例１の焼結体を化学分析した結
果、Ｌａ、Ｓｒ、Ｃａ、Ｃｒ、Ｃｏ及びＮｉ以外の主な
含有物は、６価Ｃｒ＝０．７重量％、Ａｌ2 Ｏ3 ＝０．
１４重量％、ＳｉＯ2 ＝０．１重量％以下、Ｎａ2 Ｏ＝
０．１重量％以下であった。尚、Ａｌ2 Ｏ3 は粉砕用ア
ルミナ製メディアからの混入によるものである。As a result of chemical analysis of the sintered body of Example 1, the main contents other than La, Sr, Ca, Cr, Co and Ni were hexavalent Cr = 0.7% by weight and Al 2 O. 3 = 0.
14% by weight, SiO 2 = 0.1% by weight or less, Na 2 O =
It was 0.1% by weight or less. Al 2 O 3 is due to mixing from the alumina media for grinding.
【００４３】実施例８ 実施例１の組成式においてＬａの１８モル％をＮｄに代
えた以外は、実施例１と同様の操作を行って本発明の焼
結体を得た。その特性を表２に示す。Example 8 A sintered body of the present invention was obtained in the same manner as in Example 1 except that 18 mol% of La was replaced by Nd in the composition formula of Example 1. The characteristics are shown in Table 2.
【００４４】実施例９ 表１に示す組成式の配合となるように、原料を秤量、混
合、分散し、合成した粉末をアルコール中湿式で粉砕、
分散し、スプレードライヤー時に成形助剤を加えない以
外は、実施例１〜７と同様にして成形用顆粒粉体を得
た。この顆粒粉体を圧力２５０ｋｇｆ／ｃｍ2 、温度１
６５０℃にてホットプレス成形し、φ８０×５ｍｍの焼
結体を得た。この焼結体を大気中１２００℃で４時間熱
処理した後、ダイヤモンド砥石により研削加工して表面
を仕上げた試料について特性を測定した。その結果を表
２に示す。Example 9 The raw materials were weighed, mixed and dispersed so that the composition formula shown in Table 1 was obtained, and the synthesized powder was pulverized by wet in alcohol,
Granule powders for molding were obtained in the same manner as in Examples 1 to 7 except that the particles were dispersed and no molding auxiliary was added during the spray dryer. This granular powder is pressure 250 kgf / cm 2 , temperature 1
Hot press molding was performed at 650 ° C. to obtain a sintered body of φ80 × 5 mm. After subjecting this sintered body to a heat treatment at 1200 ° C. for 4 hours in the air, the characteristics of the sample whose surface was finished by grinding with a diamond grindstone were measured. The results are shown in Table 2.
【００４５】比較例１〜４ 表１に示す各組成式の配合となるように原料を秤量、配
合し、その他は実施例１〜７と同様にして作製した焼結
体について、研削加工と表面加工を加えた後、特性を測
定した。その結果を表２に示す。Comparative Examples 1 to 4 The raw materials were weighed and blended so as to have the compositional formulas shown in Table 1, and the other processes were carried out in the same manner as in Examples 1 to 7 except for grinding and surface treatment. After processing, the properties were measured. The results are shown in Table 2.
【００４６】比較例５ 表１に示す組成式の配合となるように原料を秤量、混
合、分散し、合成した粉末を水道水中で１０時間湿式で
粉砕、分散して合成粉末の平均粒径を０．５μｍとし、
アルコールに代えて水道水を使用した以外は実施例１〜
７と同様にして焼結体を作製し、その特性を測定した。
結果を表２に示す。尚、焼結体の化学分析によれば、６
価Ｃｒ量＝３．５重量％、ＳｉＯ2 ＝０．１重量％、Ｎ
ａ2 Ｏ＝０．４重量％であり、６価Ｃｒ量は実施例１の
焼結体中の０．７重量％に比べて多量であった。Comparative Example 5 Raw materials were weighed, mixed and dispersed so as to have the compositional formula shown in Table 1, and the synthesized powder was wet-milled in tap water for 10 hours and dispersed to obtain the average particle diameter of the synthetic powder. 0.5 μm,
Examples 1 to 1 except that tap water was used instead of alcohol
A sintered body was prepared in the same manner as in No. 7, and its characteristics were measured.
The results are shown in Table 2. According to the chemical analysis of the sintered body, 6
Valence Cr amount = 3.5% by weight, SiO 2 = 0.1% by weight, N
a 2 O was 0.4% by weight, and the amount of hexavalent Cr was larger than 0.7% by weight in the sintered body of Example 1.
【００４７】[0047]
【表１】 [Table 1]
【００４８】[0048]
【表２】 [Table 2]
【００４９】上記表２から明らかなように、実施例１〜
９の焼結体は、いずれもかさ密度が高く、平均結晶粒径
が所定の範囲内であり、更に導電性、強度に優れたもの
であった。比較例１の焼結体は、組成は本発明焼結体と
同様であるが、かさ密度が低く通気性があった。同じく
比較例２及び３の焼結体も、組成は本発明焼結体と同様
であるが、平均結晶粒径が許容範囲を超えており、酸素
分圧１０-16 atm の加湿水素雰囲気中１０００℃で１０
時間熱処理した場合に室温での曲げ強さが低い値であっ
た。また、本発明の焼結体とは組成が異なるものである
比較例４の焼結体は、酸素分圧１０-16 atm の加湿水素
雰囲気中１０００℃で１０時間熱処理した後の室温での
曲げ強さが極めて低い値であった。これらの焼結体を固
体電解質型燃料電池のセパレータ（１００×１００×３
ｍｍ）に使用したところ、比較例１の焼結体を用いた場
合にはガスがリークし、比較例２〜４の焼結体を使用し
た場合には、使用後２４０時間程度でセパレータに割れ
が発生する現象が認められた。また、比較例５の焼結体
は、組成は本発明焼結体と同様であるが、水道水に含ま
れるアルカリ成分との反応によりクロム酸塩などの６価
のＣｒの化合物を生成するために耐還元性に劣り、酸素
分圧１０-16 atm の加湿水素雰囲気中１０００℃におけ
る導電率は１Ｓ／ｃｍ以下と低く、また、室温曲げ強さ
も極めて低い値であった。As is clear from Table 2 above, Examples 1 to 1
Each of the sintered bodies of No. 9 had a high bulk density, had an average crystal grain size within a predetermined range, and had excellent conductivity and strength. The sintered body of Comparative Example 1 had the same composition as that of the sintered body of the present invention, but had a low bulk density and air permeability. Similarly, the sintered bodies of Comparative Examples 2 and 3 have the same composition as that of the sintered body of the present invention, but the average crystal grain size exceeds the permissible range, and the sintered body is 1000 in a humidified hydrogen atmosphere with an oxygen partial pressure of 10 −16 atm. 10 at ℃
When heat-treated for a long time, the bending strength at room temperature was low. The sintered body of Comparative Example 4 having a composition different from that of the sintered body of the present invention was bent at room temperature after heat treatment at 1000 ° C. for 10 hours in a humidified hydrogen atmosphere with an oxygen partial pressure of 10 −16 atm. The strength was extremely low. These sintered compacts were used as separators (100 × 100 × 3) for solid oxide fuel cells.
mm), gas leaks when the sintered body of Comparative Example 1 is used, and when the sintered bodies of Comparative Examples 2 to 4 are used, the separator cracks in about 240 hours after use. Was observed. The composition of the sintered body of Comparative Example 5 is the same as that of the sintered body of the present invention, but a hexavalent Cr compound such as chromate is generated by the reaction with the alkaline component contained in tap water. However, the electrical conductivity at 1000 ° C. in a humidified hydrogen atmosphere having an oxygen partial pressure of 10 −16 atm was as low as 1 S / cm or less, and the bending strength at room temperature was also extremely low.
───────────────────────────────────────────────────── 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 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Kawanami 3-24 No. 24 Tonosato Onomachi, Sakai City, Osaka Prefecture Nikkato Co., Ltd.
Claims (4)
3 （式中、ＡはＣａ及びＳｒの少なくとも一種を示し、
０＜ｘ≦０．２であり、ＭはＣｏ及びＮｉの少なくとも
一種を示し、０＜ｙ＜０．１である）で表わされるペロ
ブスカイト型結晶構造を有する焼結体であり、（２）焼
結体のかさ密度が理論密度の９２％以上、（３）焼結体
の平均結晶粒径が２〜３０μｍ、（４）１０００℃での
酸素分圧が１０-16 atm となる加湿水素雰囲気中１００
０℃における導電率が１Ｓ／ｃｍ以上、（５）室温曲げ
強さが１０ｋｇｆ／ｍｍ2 以上であり、１０００℃での
酸素分圧が１０-16 atm となる加湿水素雰囲気中１００
０℃で１０時間熱処理した後の焼結体の室温曲げ強さが
８ｋｇｆ／ｍｍ2 以上であることを特徴とする耐熱導電
性セラミックス。(1) Chemical formula La 1-x A x Cr 1- y My O
3 (In the formula, A represents at least one of Ca and Sr,
0 <x ≦ 0.2, M represents at least one of Co and Ni, and 0 <y <0.1), which is a sintered body having a perovskite type crystal structure, and In a humidified hydrogen atmosphere in which the bulk density of the aggregate is 92% or more of the theoretical density, (3) the average crystal grain size of the sintered body is 2 to 30 μm, and (4) the oxygen partial pressure at 1000 ° C. is 10 −16 atm. 100
Conductivity at 0 ° C is 1 S / cm or more, (5) Room temperature bending strength is 10 kgf / mm 2 or more, and oxygen partial pressure at 1000 ° C is 10 -16 atm in a humidified hydrogen atmosphere.
A heat-resistant conductive ceramics characterized in that the room temperature bending strength of the sintered body after heat treatment at 0 ° C. for 10 hours is 8 kgf / mm 2 or more.
わされる焼結体であって、０．１２＜ｘ≦０．２、０．
０５≦ｙ＜０．１、且つ０．１５≦ｘ＋ｙ≦０．２５で
あり、平均結晶粒径が２〜２０μｍである請求項１に記
載の耐熱導電性セラミックス。2. A sintered body represented by the chemical formula La 1-x A x Cr 1-y M y O 3 , wherein 0.12 <x ≦ 0.2, 0.
The heat resistant conductive ceramics according to claim 1, wherein 05 ≦ y <0.1 and 0.15 ≦ x + y ≦ 0.25, and the average crystal grain size is 2 to 20 μm.
わされる焼結体であって、０＜ｘ≦０．１２、０＜ｙ≦
０．０５、且つ０＜ｘ＋ｙ≦０．１５であり、平均結晶
粒径が２〜３０μｍである請求項１に記載の耐熱導電性
セラミックス。3. A sintered body represented by the chemical formula La 1-x A x Cr 1- y My O 3 , wherein 0 <x ≦ 0.12 and 0 <y ≦
The heat resistant conductive ceramics according to claim 1, wherein 0.05 and 0 <x + y ≦ 0.15, and the average crystal grain size is 2 to 30 μm.
表わされる焼結体のＬａの５０モル％以下をイットリウ
ム及び原子番号５８から７１の希土類元素の少なくとも
一種で置換したものである請求項１乃至請求項３のいず
れか一項に記載の耐熱導電性セラミックス。4. Lat in the sintered body represented by the chemical formula La 1-x A x Cr 1-y M y O 3 is replaced by yttrium and at least one rare earth element having an atomic number of 58 to 71 in an amount of 50 mol% or less. The heat-resistant conductive ceramics according to any one of claims 1 to 3, which is a material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5295346A JPH07149564A (en) | 1993-11-25 | 1993-11-25 | Heat resistant and electrically conductive ceramic |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5295346A JPH07149564A (en) | 1993-11-25 | 1993-11-25 | Heat resistant and electrically conductive ceramic |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07149564A true JPH07149564A (en) | 1995-06-13 |
Family
ID=17819427
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5295346A Pending JPH07149564A (en) | 1993-11-25 | 1993-11-25 | Heat resistant and electrically conductive ceramic |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07149564A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5885878B1 (en) * | 2014-12-26 | 2016-03-16 | 日本碍子株式会社 | Interconnector material |
-
1993
- 1993-11-25 JP JP5295346A patent/JPH07149564A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5885878B1 (en) * | 2014-12-26 | 2016-03-16 | 日本碍子株式会社 | Interconnector material |
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