JPH0193403A - Production of ceramic-based superconducting material and apparatus therefor - Google Patents
Production of ceramic-based superconducting material and apparatus thereforInfo
- Publication number
- JPH0193403A JPH0193403A JP62249921A JP24992187A JPH0193403A JP H0193403 A JPH0193403 A JP H0193403A JP 62249921 A JP62249921 A JP 62249921A JP 24992187 A JP24992187 A JP 24992187A JP H0193403 A JPH0193403 A JP H0193403A
- Authority
- JP
- Japan
- Prior art keywords
- plasma
- raw material
- ceramic
- ceramic superconducting
- superconducting material
- 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
- 239000000463 material Substances 0.000 title claims abstract description 51
- 239000000919 ceramic Substances 0.000 title claims abstract description 33
- 238000004519 manufacturing process Methods 0.000 title claims description 15
- 239000000843 powder Substances 0.000 claims abstract description 56
- 239000002994 raw material Substances 0.000 claims abstract description 31
- 239000002245 particle Substances 0.000 claims abstract description 29
- 238000010438 heat treatment Methods 0.000 claims abstract description 13
- 238000001816 cooling Methods 0.000 claims abstract description 5
- 238000001704 evaporation Methods 0.000 claims abstract 3
- 210000002381 plasma Anatomy 0.000 claims description 65
- 238000000034 method Methods 0.000 claims description 20
- 238000005245 sintering Methods 0.000 claims description 16
- 238000000465 moulding Methods 0.000 claims description 5
- 230000008016 vaporization Effects 0.000 claims description 5
- 238000012545 processing Methods 0.000 claims description 4
- 238000005520 cutting process Methods 0.000 claims description 2
- 239000000126 substance Substances 0.000 abstract description 6
- 229910052761 rare earth metal Inorganic materials 0.000 abstract description 5
- 238000005516 engineering process Methods 0.000 abstract description 4
- 238000011084 recovery Methods 0.000 abstract description 2
- 239000007789 gas Substances 0.000 description 23
- 239000000203 mixture Substances 0.000 description 9
- 238000007796 conventional method Methods 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 235000013339 cereals Nutrition 0.000 description 5
- 239000010949 copper Substances 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 238000009826 distribution Methods 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- 238000002844 melting Methods 0.000 description 5
- 230000008018 melting Effects 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 238000010298 pulverizing process Methods 0.000 description 5
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 4
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000005204 segregation Methods 0.000 description 4
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 3
- 150000001342 alkaline earth metals Chemical class 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010419 fine particle Substances 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910052788 barium Inorganic materials 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 238000000280 densification Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 150000002823 nitrates Chemical class 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910052691 Erbium Inorganic materials 0.000 description 1
- 206010021143 Hypoxia Diseases 0.000 description 1
- 238000005481 NMR spectroscopy Methods 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 240000007594 Oryza sativa Species 0.000 description 1
- 235000007164 Oryza sativa Nutrition 0.000 description 1
- 229910052775 Thulium Inorganic materials 0.000 description 1
- 229910052769 Ytterbium Inorganic materials 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 229910001422 barium ion Inorganic materials 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000000112 cooling gas Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 150000004678 hydrides Chemical class 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 150000003891 oxalate salts Chemical class 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 238000009832 plasma treatment Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 229910052705 radium Inorganic materials 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 235000009566 rice Nutrition 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000011163 secondary particle Substances 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 210000002784 stomach Anatomy 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052712 strontium Inorganic materials 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 239000013077 target material Substances 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- 238000003325 tomography Methods 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は酸化物系高温超電導材料等を製造する方法およ
び装置に関するもので、この発明によって臨界電流密度
が大きい超電導材料の製造が容易となる。Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method and apparatus for producing oxide-based high-temperature superconducting materials, etc. The present invention facilitates producing superconducting materials with high critical current density. .
（従来の技術）
最近、Ｙ、Ｂａ２Ｃｕ３０．−、ｌ（Ｘは酸素欠損度）
の組成に代表される各種の酸化物系セラミックスがその
超電導臨界温度（Ｔｃ）が液体窒素温度を越すところの
いわゆる高温超電導物質として発見され、その実用化へ
の研究・開発が各方面で推進されている。そしてこれを
磁気浮上列車、核磁気共鳴断層撮影装置、超電導推進船
等への応用を図る場合には、単位断面積あたりの回通電
流量の大きい導体（例えば線材、テープ）すなわち臨界
電流密度（Ｊｃ）の大きい超電導材料が必須のものとし
て製造技術確立が要請される。(Prior art) Recently, Y, Ba2Cu30. -, l (X is degree of oxygen deficiency)
Various oxide-based ceramics, represented by the composition of ing. When applying this to magnetically levitated trains, nuclear magnetic resonance tomography devices, superconducting propulsion ships, etc., conductors (e.g. wires, tapes) with a large amount of circulating current per unit cross-sectional area, i.e. critical current density (Jc ) is essential, and the establishment of manufacturing technology is required.
しかしながら、これら酸化物系セラミックスの超電導特
性に関して、Ｔｃについては９０に以上の高温領域とな
し得ることが基礎物質すなわち該種セラミックスの粉体
等において確認されているものの大きなＪｃの達成は困
難性大とされており、実用化の研究開発の実績の蓄積が
ないこともあり、Ｊｃ改善のための有効かつ具体的な提
案等はほとんど報告されていない。However, regarding the superconducting properties of these oxide-based ceramics, although it has been confirmed that Tc can be achieved in the high temperature range of 90 or higher in the basic material, ie, the powder of such ceramics, it is extremely difficult to achieve a large Jc. Partly because there is no accumulation of research and development results for practical application, very few effective and specific proposals for improving Jc have been reported.
（発明が解決しようとする問題点）
Ｙ１Ｂａ２Ｃｕ３Ｏ７−Ｈやこわと類似の形態の酸化物
等のセラミックス系超電導材料の製造は、 Ｌａ２０．
。(Problems to be Solved by the Invention) Ceramic superconducting materials such as Y1Ba2Cu3O7-H and oxides having a similar form to stiffness can be manufactured using La20.
.
Ｙ２Ｏ，、５ｒＣ０３，ｌ１ａＣＯ，、、ＣｕＯなとの
原料粉末を超電導物質組成となる所定の割合で配合し、
これを仮焼して炭酸等の目的外の成分の揮発除去を図り
、ついで粉砕していったん中間材料としてのセラミック
ス系超電導物質の粉体とし、この粉体を加圧成形して所
望の材料の形状としたあと熱処理（仕上げ焼結）すると
いう方法によって行うことが一般的である。Blending raw material powders such as Y2O, 5rC03, l1aCO, and CuO in a predetermined ratio to form a superconducting material composition,
This is calcined to volatilize and remove unintended components such as carbonic acid, and then pulverized to produce ceramic superconducting material powder as an intermediate material, and this powder is pressure-molded to form the desired material. This is generally done by heat treatment (finish sintering) after shaping.
ところで、セラミツスス系超電導物質の粉体は、粒度が
小さく、かつ分散性が高いほど緻密かつ成分的に均一な
焼結体すなわち超電導材料が得られる。超電導材料が緻
密であれば粒界の影響が小さくなるため臨界温度Ｔｃ、
臨界電流密度Ｊｃおよび臨界磁場Ｈｃは高くなる。これ
により、電気機器の高性能かつ小型化を図ることができ
る。また微細かつ複雑な加工が可能となり電子デバイス
に応用することが可能となる。したがって、超電導材料
の緻密化が電気機器および電子デバイスの性能向上にも
たらす効果は極めて大きい。Incidentally, the smaller the particle size and the higher the dispersibility of the powder of the ceramitsu-based superconducting material, the more dense and compositionally uniform a sintered body, ie, the superconducting material, can be obtained. If the superconducting material is dense, the influence of grain boundaries will be reduced, so the critical temperature Tc,
Critical current density Jc and critical magnetic field Hc become higher. Thereby, it is possible to achieve high performance and miniaturization of electrical equipment. Furthermore, it becomes possible to perform fine and complicated processing, making it possible to apply it to electronic devices. Therefore, the densification of superconducting materials has an extremely large effect on improving the performance of electrical equipment and electronic devices.
しかるに上記従来の製造方法において得られるセラミッ
クス系超電導物質粉は、Ｌａ２Ｏ５＋ Ｙ２Ｏ３＊Ｓｒ
ＣＯ３，ＢａＣＯ３，ＣｕＯ等の形態の複数種の成分原
料をボットミル等で機械的に粉砕・分散しているだけで
あるので粒度は数μｍから数１０ｕｍにわたり分布する
。このような粉体を加圧成形したものは、複数種の組成
の、かつ粗粒細粒が入り混った状態を呈するので、部分
的（セミマクロ的）な成分の不均一はさけがたく、その
上、（：ｕＯ（融点： １０２６℃）のような低融点物
質とＹ２Ｏ３（融点： ２４１０℃）のような高融点物
質の混合物であるため上記のようなセミマクロ的な成分
の不均一がある場合には仕上げ焼結による成分の均一拡
散の達成は極めて難かしい。すなわち、従来法では均質
で緻密な焼結体から形成される超電導材料（バルク）が
なかなか得られない。これが臨界温度Ｔｃ、臨界電流密
度Ｊｃおよび臨界磁場ｔｉｃの向上に対して製造技術面
での大きな障害となっている。すなわち、別の角度から
言うならば、極めて微細なセラミックス系超電導物質の
粉体が工業的に製造入手できれば、セラミックス系超電
導材料の実用特性（例えばＴｃ、 Ｊｃ）の向上・安定
に供するところ甚大ということになり、その実現が要請
されていた。However, the ceramic superconducting material powder obtained by the above conventional manufacturing method is La2O5+ Y2O3*Sr
Since a plurality of raw materials in the form of CO3, BaCO3, CuO, etc. are simply ground and dispersed mechanically using a bot mill or the like, the particle size ranges from several μm to several tens of μm. Pressure-molded products of this type have multiple types of composition and a mixture of coarse and fine particles, so partial (semi-macro) non-uniformity of the components is unavoidable. Furthermore, since it is a mixture of a low melting point substance such as (:uO (melting point: 1026°C)) and a high melting point substance such as Y2O3 (melting point: 2410°C), there is semi-macroscopic non-uniformity of the components as described above. In some cases, it is extremely difficult to achieve uniform diffusion of components by final sintering. In other words, with conventional methods, it is difficult to obtain a superconducting material (bulk) formed from a homogeneous and dense sintered body. This is due to the critical temperature Tc, This is a major obstacle in terms of manufacturing technology for improving the critical current density Jc and critical magnetic field tic.In other words, from a different perspective, it is difficult to industrially manufacture extremely fine ceramic superconducting material powder. If it could be obtained, it would greatly contribute to improving and stabilizing the practical characteristics (eg, Tc, Jc) of ceramic superconducting materials, and there was a demand for its realization.
（問題点を解決するための手段）
本発明は臨界電流密度Ｊｃの大きいセラミックス系超電
導材料を提供することを目的とするもので、その要旨は
、「セラミックス系超電導物質の原料を高温加熱してい
ったん蒸発させてからこれを冷却・凝固させて平均粒径
１ミクロン以下の微粉として回収すること、およびこの
ようにし、て得られた微粉をそのまま成形した後に、も
しくは中空容器に充填して所要の加工および／もしくは
熱処理を行った後に仕上げ焼結を行ってセラミックス系
Ｍ電導材料とすること」にある。(Means for Solving the Problems) The purpose of the present invention is to provide a ceramic superconducting material with a large critical current density Jc. Once evaporated, it is cooled and solidified to recover a fine powder with an average particle size of 1 micron or less, and the fine powder obtained in this way can be molded as it is or filled into a hollow container to form the desired shape. After processing and/or heat treatment, finish sintering is performed to obtain a ceramic M conductive material.
（作用）
こ発明の方法は熱プラズマ等の高温加熱手段を用いてセ
ラミックス系超電導物質の原料を全部−旦気化せしめ、
ついで気体から粒子を析出させることを基本としてるの
で、次のような数々の特徴をもっている。(Function) The method of the present invention uses high-temperature heating means such as thermal plasma to vaporize all of the raw materials of the ceramic superconducting material,
Since the method is basically to precipitate particles from a gas, it has the following characteristics.
■原料の種類、形態によらず、気化された状態で一旦理
想的な均一性が確保される。■Ideal uniformity is ensured once the material is vaporized, regardless of the type or form of the raw material.
■空間において気体から析出して得られる粒子から出発
するものであるため、目的物としての粉体は充分に微細
となる。(2) Since it starts from particles obtained by precipitation from gas in space, the target powder is sufficiently fine.
■気体から液体を経て固体となる過程において、液体状
態のときに粒子同士が衝突・合体して適度の大きさに成
長できる。この粒子の寸法は原料供給ｆｆｌ（ｇ／ｍ１
ｎ） 、プラズマへの電力供給量、プラズマガス量、プ
ラズマガスの冷却速度（液体状態での滞留時間）等によ
って制御できる。■In the process of changing from gas to liquid to solid, particles collide and coalesce while in the liquid state, allowing them to grow to an appropriate size. The size of this particle is the raw material supply ffl (g/m1
n) It can be controlled by the amount of power supplied to the plasma, the amount of plasma gas, the cooling rate of the plasma gas (residence time in a liquid state), etc.
■液体の表面張力の作用により粒子は球形になるで得ら
れる固体も、球形あるいは球に近い形をした緻密な粒子
となる。また、末法による粒子は粉砕、あるいは粉砕分
級により得られる従来法によるものと比べて粒度分布範
囲が狭く分散性が優れる。■The particles become spherical due to the action of the surface tension of the liquid, and the resulting solid also becomes dense particles that are spherical or nearly spherical. Furthermore, the particles obtained by the powder method have a narrower particle size distribution range and excellent dispersibility than those obtained by the conventional method, which are obtained by pulverization or pulverization and classification.
■直流プラズマ、高周波プラズマ、直流プラズマと高周
波プラズマから成るハイブリッドプラズマ等におけるプ
ラズマガス流は充分に急速な冷却ができるので析出する
粒子間に成分の偏析は少く均質である。■The plasma gas flow in direct current plasma, high frequency plasma, hybrid plasma consisting of direct current plasma and high frequency plasma, etc. can be cooled sufficiently rapidly, so that there is little segregation of components between the precipitated particles and they are homogeneous.
■得られる超電導物質粉は結晶水、炭酸塩、硝酸塩等の
揮発成分を含まない。■The superconducting material powder obtained does not contain volatile components such as crystal water, carbonates, and nitrates.
上記のような特徴を有する本発明の方法によって得られ
るセラミックス系超電導物質粉体は、従来の技術では必
須とされている仮焼した後の粉砕という工程をまったく
要することなしに、超電導材料製造のための加圧成形用
に使うことができる。そして、このような粉体を成形し
て仕上げ焼結することにより成分の均質な緻密な焼結体
すなわちＪｃ、 Ｔｃの高い超電導材料を得るとができ
る。The ceramic superconducting material powder obtained by the method of the present invention having the above-mentioned characteristics can be used in the production of superconducting materials without requiring any steps of pulverization after calcination, which are essential in conventional techniques. Can be used for pressure molding. By molding such powder and final sintering, it is possible to obtain a dense sintered body with homogeneous components, that is, a superconducting material with high Jc and Tc.
さて、成分の均質な緻密な焼結体は基本的には細かい粒
子を、均一に混合し、緻密に成形した後、仕上げ焼結す
ることにより得られるが、あまり細かい粒子は粒子同士
が凝集し二次粒子の形成を起こし、均質で緻密な成形体
は得られなくなる。発明者らの得た知見では、平均粒子
径が０．１〜１．０μｍの範囲にあって粒度分布幅の狭
い粉体が得られ、好結果をもたらす。すなわち、前記の
ような粉体を用いると、より低い焼結温度で、より短い
焼結時間で緻密化する。この場合、焼結体の結晶粒度は
焼結温度が低い程、細かくなるので、焼結温度の選択に
より結晶粒度の制御も可能となる。Now, a dense sintered body with homogeneous ingredients can basically be obtained by uniformly mixing fine particles, forming them into a dense shape, and then final sintering them. This causes the formation of secondary particles, making it impossible to obtain a homogeneous and dense molded body. According to the knowledge obtained by the inventors, a powder having an average particle diameter in the range of 0.1 to 1.0 μm and a narrow particle size distribution can be obtained, and good results can be obtained. That is, when the above-mentioned powder is used, densification can be achieved at a lower sintering temperature and in a shorter sintering time. In this case, the lower the sintering temperature is, the finer the crystal grain size of the sintered body becomes, so the crystal grain size can be controlled by selecting the sintering temperature.
さて、本発明において、高温加熱する手段としては高融
点の希土類元素あるいはその化合物を蒸発させることか
ら４０００〜５０００℃以上の超高温度が必要となるこ
とより熱プラズマ例えば直流プラズマ、高周波プラズマ
、直流プラズマと高周波プラズマからなるハイブリッド
、移行プラズマおよび炭素電極マークプラズマ等が使わ
れる。Now, in the present invention, as means for high-temperature heating, an ultra-high temperature of 4000 to 5000°C or more is required to evaporate a rare earth element or its compound with a high melting point, so thermal plasma such as direct current plasma, high frequency plasma, direct current Hybrids consisting of plasma and high-frequency plasma, transitional plasma, carbon electrode mark plasma, etc. are used.
セラミックス系超電導物質の原料には目的とする物質の
組成に応じて適正なものが選ばれるが、ＬＩＡ２（：ｕ
＋０７−ｘ型の酸化物系高温超電導物質の製造において
は希土類元素（Ｌ）、アルカリ土類金属（Ａ）および銅
が用いられる。希土類から選ばれるものは例えば、Ｌａ
、 Ｅｎ、 Ｄｙ、 ）ｌｏ、 Ｅｒ、 Ｔｍ、 Ｙｂ
またはＹであり、アルカリ土類金属から選ばれるものは
Ｃａ、 Ｓｒ、 ＲａまたはＢａである。これらの原料
は元素単体である必要はなく、気体状態もしくは溶融状
態で酸素雰囲気下において、酸化物を生成し、他の成分
と分離できるものであわばよい。すなわち、単体以外の
形態としては、例えば、硫化物、炭化物、窒化物、水酸
化物、水素化物、硝酸塩、しゆう酸塩、炭酸塩、硫酸塩
、および当然のことながら酸化物等がある。Appropriate raw materials for ceramic superconducting materials are selected depending on the composition of the target material, but LIA2 (:u
In the production of +07-x type oxide-based high temperature superconducting materials, rare earth elements (L), alkaline earth metals (A) and copper are used. Examples of rare earth elements include La
, En, Dy, )lo, Er, Tm, Yb
or Y, and those selected from alkaline earth metals are Ca, Sr, Ra or Ba. These raw materials do not need to be single elements, but may be any material that can generate oxides and be separated from other components in an oxygen atmosphere in a gaseous or molten state. That is, forms other than simple substances include, for example, sulfides, carbides, nitrides, hydroxides, hydrides, nitrates, oxalates, carbonates, sulfates, and, of course, oxides.
プラズマガスとしては不活性ガス、 ０２＋Ｎ２＋Ｈ２
＋およびＮ２０ガスが使用可能である。通常Ａｒガスあ
るいは（Ａｒ＋０２）ガスを用いるがプラズマの熱出力
の調整等のためＮ２．Ｎ２．Ｈ，０の混入も可能である
。しかしいずれの場合においてもプラズマガス流の温度
低下にしたがいそのガス流から凝固析出してくる希土類
元素、アルカリ土類金属および銅元素に充分に酸素に付
与できるように、初めからプラズマガスに充分０□を含
ませておくか、もしくはプラズマガス自身が０２を全く
含まないか、もしくは０２が少ない場合には、プラズマ
ガス流に外部から０２ガスを添加するか、または周囲を
充分に０２雰囲気にしておくか、いずれかの手法を請す
る必要がある。Inert gas as plasma gas, 02+N2+H2
+ and N20 gases are available. Usually, Ar gas or (Ar+02) gas is used, but N2 gas is used to adjust the thermal output of the plasma. N2. It is also possible to mix H,0. However, in either case, the plasma gas is sufficiently 00000 from the beginning so that sufficient oxygen can be added to the rare earth elements, alkaline earth metals, and copper elements that solidify and precipitate from the gas flow as the temperature of the plasma gas flow decreases. □, or if the plasma gas itself does not contain 02 at all or has a small amount of 02, add 02 gas to the plasma gas flow from the outside, or create a sufficient 02 atmosphere around it. You need to either leave it or ask for one of these methods.
このようにして熱プラズマガス流から凝固析出した微粉
はサイクロンあるいはバグフィルタ−で補集する。かく
して得られるセラミックス系超電導物質粉を成形−焼結
することにより高密度で均質な超電導材料をつくること
ができる。The fine powder thus solidified and precipitated from the hot plasma gas stream is collected by a cyclone or bag filter. By molding and sintering the ceramic superconducting powder thus obtained, a high-density and homogeneous superconducting material can be produced.
以下、実施例によってさらに詳細に説明する。Hereinafter, the present invention will be explained in more detail with reference to Examples.
（実施例）
（１）実施例１［セラミックス系超電導物質粉体の製造
］
粒度が１０（１〜４４ｕｔｎのＹ２Ｏ３，ＢａＣＯ３，
ＣｕＯ粉末を原子数比でＹ：Ｂａ：Ｃｕ ＝ １ ：
２ ： ３の割合となるように配合してボットミルに入
れて１２ｈｒ処理して均一に混合した。この混合原料を
第１図に示すハイブリッドプラズマの３木の直流プラズ
マ流の合流点に４ｇ／ｍｉｎの割合で連続的に供給した
。このハイブリッドプラズマは大気から遮断されている
。３本の直流プラズマ出力は１５に胃×３、プラズマガ
スはＡｒガスで１５１７ｍ１ｎｘ ３ 、高周波プラズ
マは出力８０ｋｗ、高周波プラズマガスはＡｒ＋ １０
９６０２になるよう高周波プラズマ上部から０２ガスを
添加している。(Example) (1) Example 1 [Production of ceramic superconducting material powder] Particle size is 10 (1 to 44 utn Y2O3, BaCO3,
The atomic ratio of CuO powder is Y:Ba:Cu = 1:
The mixture was blended at a ratio of 2:3 and placed in a bot mill for 12 hours to mix uniformly. This mixed raw material was continuously supplied at a rate of 4 g/min to the confluence of three DC plasma streams of the hybrid plasma shown in FIG. This hybrid plasma is shielded from the atmosphere. The output of the three DC plasmas is 15 and 3 stomachs, the plasma gas is Ar gas, 1517m1nx 3, the high frequency plasma is 80kw, the high frequency plasma gas is Ar+ 10
02 gas is added from the top of the high-frequency plasma so that the temperature becomes 9602.
ハイブリッドプラズマの反応容器の内径は７５ ｍｍφ
で高周波プラズマの下方で反応容器の内壁から中心に向
かって０２を１００１／ｍｉｎ吹込んでいる。このプラ
ズマによって上記の混合原料は瞬時に高温加熱されて全
量が一旦蒸発したが、ひき続いて急冷されて析出し、凝
固して微細な粉体となった。これらの生成した粉体は反
応容器に接続されたバグフィルタ−で捕獲した。The inner diameter of the hybrid plasma reaction vessel is 75 mmφ
02 was blown at 1001/min from the inner wall of the reaction vessel toward the center below the high-frequency plasma. The above-mentioned mixed raw material was instantaneously heated to a high temperature by this plasma and the entire amount evaporated once, but it was subsequently rapidly cooled, precipitated, and solidified into fine powder. These generated powders were captured by a bag filter connected to the reaction vessel.
この粉体は比表面積が１０〜２０ｍ＋２７ｇで、粒径は
０．１〜１．０ＪＪＯＩゆで透過型電子顕微鏡で観察し
たところほぼ球形であった。この電子顕微鏡での粒子形
状の観察と同時にエネルギー分散型Ｘ線分析計により無
作為に抽出した数個の粒子の構成成分の分析を行ったが
粒子の大小をとわず全粒子はぼ同じ組成（ＹＢａ２Ｃｕ
３０ｙ−ｘ）を示した。This powder had a specific surface area of 10 to 20 m + 27 g, and a particle size of 0.1 to 1.0 JJOI. When observed under a transmission electron microscope after boiling, it was found to be approximately spherical. At the same time as the particle shape was observed using an electron microscope, the constituent components of several randomly selected particles were analyzed using an energy dispersive (YBa2Cu
30y-x).
ここで、従来法によるセラミックス粉体の性状を示して
前記の本発明法のものと比較する。本例上記の配合粉末
原料に成形（造粒）−仮焼（９５０℃×２時間）−粉砕
（通常のボールミル処理）を施して得られた粉体は、粒
径が０．１μｍ〜３０ｕｍに広く分布し、大きい粒はど
粒内においての成分の偏析が観察された。Here, the properties of ceramic powder obtained by the conventional method will be shown and compared with those obtained by the method of the present invention. In this example, the powder obtained by molding (granulating), calcining (950°C x 2 hours) and pulverizing (normal ball milling) the above blended powder raw materials has a particle size of 0.1 μm to 30 μm. Wide distribution and segregation of components within large grains was observed.
（２）実施例２［超電導材料の製造■］実施例１の本発
明法による粉体を直径２５＋ｓｍのダイスにとり１００
ｋｇ／ｃ＋ｓ”の−軸プレスしたあと７ｔｏｎ／ｃｍ”
の静水圧プレス（（：ＩＰ）を行い直径２０ｍｍ厚さ５
１ＩＩｆｌ＋の円板状のバルクとした。この円板につい
て、１００に酸素雰囲気下で９００℃ｘ８ｈｒの焼結を
行った。この焼結体は １．０〜２．０μｍの整った結
晶粒を呈した。この焼結体の電気抵抗を測定したところ
再現性よく超電導特性（Ｔｃ＝９３に、Ｊｃ −１２０
０Ａ／ｃｍ２）を示した。(2) Example 2 [Manufacture of superconducting material ■] The powder produced by the method of the present invention in Example 1 was put into a die with a diameter of 25+sm, and 100
7ton/cm” after negative axis pressing of “kg/c+s”
Perform isostatic press ((:IP) of 20 mm in diameter and 5 in thickness.
It was made into a disc-shaped bulk of 1IIfl+. This disk was sintered at 900° C. for 8 hours in an oxygen atmosphere. This sintered body exhibited regular crystal grains of 1.0 to 2.0 μm. When the electrical resistance of this sintered body was measured, it had superconducting properties with good reproducibility (Tc = 93, Jc -120
0A/cm2).
ここで、比較のため従来法によるセラミックス系超電導
物質粉体を用いての焼結体の製造を行った。すなわち、
前記実施例１において記述した従来法による粉体（平均
粒径：約３μＩ９粒径分布範囲＝０．１〜３０μｍ）に
ついて、本例上記の本発明法粉体の場合と同一の条件に
て成形（円板化）し、この成形体について１００％酸素
雰囲気下で９００℃×８ ｈｒ、ならびに９５０℃Ｘ８
ｈｒの焼結を行った。これらのうち、９００℃処理のも
のは充分な焼結に至らなかった。また、９５０℃処理の
ものは、結晶粒の大多数がｌＯ〜２０ｕｍの大きさであ
り、各部分に気泡が散見され、また粒内の成分偏析が認
められた。この９５０℃処理の焼結体の超電導特性は、
バラツキが太きく Ｔｃ＝ ８０〜９０に、Ｊｃ＝ ５
０〜１５０Ａ／ｃｍ”）と、本発明による粉体から製造
されるものと比べて成績は不良であった。Here, for comparison, a sintered body was manufactured using ceramic superconducting material powder by a conventional method. That is,
The powder produced by the conventional method described in Example 1 (average particle size: approximately 3 μI9 particle size distribution range = 0.1 to 30 μm) was molded under the same conditions as in the case of the powder produced by the present invention method described above in this example. (formed into a disc), and this molded body was heated at 900°C x 8 hr and at 950°C x 8 hr in a 100% oxygen atmosphere.
Sintering was performed for hr. Among these, those treated at 900°C did not lead to sufficient sintering. In addition, in the case of the sample treated at 950°C, the majority of crystal grains had a size of 10 to 20 um, bubbles were found here and there, and segregation of components within the grains was observed. The superconducting properties of the sintered body treated at 950°C are as follows:
Wide variation Tc = 80-90, Jc = 5
0-150 A/cm''), which was poor compared to that produced from the powder according to the invention.
（３）実施例３［超電導材料の製造■コ実施例１の本発
明法による粉体に酸素補給源として少量のＡｇＯ微粉末
を添加して均一に混合し、外径２０ｍｍ厚さ２ ｍｍの
１８−８ステンレス鋼管の中に充填し、孔型圧延および
引抜きにょる縮径加工を施して、最終寸法２＋ｎｍφの
細丸線状の超電導材料とした。この細線に９５０℃Ｘ８
ｈｒの仕上げ焼結、およびそれにひきつづく炉中徐冷の
処理を施した。この処理を行った細線の臨界温度および
臨界電流密度を測定したところ、それぞれ９１ Ｋ、８
００Ａ／ｃｍ２であった。(3) Example 3 [Manufacture of superconducting material] A small amount of AgO fine powder was added as an oxygen supply source to the powder produced by the method of the present invention in Example 1, and mixed uniformly to form a powder with an outer diameter of 20 mm and a thickness of 2 mm. The superconducting material was filled into a 18-8 stainless steel tube and subjected to diameter reduction processing by groove rolling and drawing to obtain a thin round wire-shaped superconducting material with a final dimension of 2+nmφ. 950℃ x 8 on this thin line
Finish sintering for 1 hour and subsequent slow cooling in a furnace were performed. When the critical temperature and critical current density of the thin wire subjected to this treatment were measured, they were 91 K and 8 K, respectively.
00A/cm2.
実施例１に示す比較材（従来法による粉体）につき同様
の実験を行フたところ、臨界温度と臨界電流密度はそれ
ぞれ８５ Ｋ、 １００Ａ／ｃｍ２であった。When a similar experiment was carried out on the comparative material (powder produced by the conventional method) shown in Example 1, the critical temperature and critical current density were 85 K and 100 A/cm2, respectively.
（４）実施例４
Ｙイオン、Ｂａイオン、Ｃｕイオンを原子数比Ｙ：Ｂａ
：Ｃ：ｕ ＝ １ ： ２ ： ３の割合で含む硝酸塩
水溶液にシュウ酸を加えＹ、 Ｂａ、 Ｃｕの均一に混
ざったシュウ酸塩を析出させた。この析出物を乾燥し、
ボールミルにて粉砕し、３２５メツシユのふるいで４４
μの以下の粉体を得た。(4) Example 4 Y ions, Ba ions, and Cu ions at an atomic ratio of Y:Ba
Oxalic acid was added to a nitrate aqueous solution containing a ratio of :C:u=1:2:3 to precipitate an oxalate containing a uniform mixture of Y, Ba, and Cu. Dry this precipitate,
Grind with a ball mill and pass through a 325 mesh sieve to 44
A powder of μ below was obtained.
この４４μｍ以下の粉体を第１図に示すハイブリッドプ
ラズマ装置の高周波プラズマだけを稼動させた反応炉に
、３ｇ／ｍｉｎの割合で連続投入した。高周波プラズマ
の出力は８０ｋｗでプラズマガスは（＾ｒ＋ｔｏ！ｋ
０２）ガステ５０ ｉ／ｍｉｎテある。以下、実ｈ’６
例１と同様に反応容器下部から０□を１００２７ｍ１ｎ
吹込み、このような熱プラズマ処理条件下で生成した粉
体をバグフィルタ−で捕獲した。捕獲した粉体の粒度は
１〜１００μｍに分布し、細かいものから凝集し大きい
ものまで混ざっていた。これは実施例１の場合に比べて
高周波プラズマの熱出力が足りないこと、投入した原料
がプラズマの高温部を通らず低い温度を通過してきたこ
と等により投入原料の気化が必ずしも完全ではなく、液
体状態で合体したこと等に起因する。This powder of 44 μm or less was continuously charged at a rate of 3 g/min into a reactor in which only high-frequency plasma of a hybrid plasma device shown in FIG. 1 was operated. The output of high-frequency plasma is 80kW, and the plasma gas is (^r+to!k
02) Gaste 50 i/min. Below, actual h'6
As in Example 1, 0□ is 10027 m1n from the bottom of the reaction vessel.
The powder produced under such thermal plasma treatment conditions was captured by a bag filter. The particle size of the captured powder was distributed in the range of 1 to 100 μm, and was a mixture of fine particles to agglomerated large particles. This is because the heat output of the high-frequency plasma is insufficient compared to the case of Example 1, and the input raw material does not pass through the high-temperature part of the plasma but passes through a low temperature, so the vaporization of the input raw material is not necessarily complete. This is due to the fact that they were combined in a liquid state.
この捕獲した粉体を、■そのままの粒度分布のもの、０
１０μｍ以下のものく粉砕・分級して得る）、■５μｍ
以下のもの（粉砕・分級して得る）、３種の粉体とした
。This captured powder is divided into ■ those with the same particle size distribution, 0
10μm or less (obtained by crushing and classifying), ■5μm
The following three types of powders (obtained by pulverization and classification) were prepared.
この３種の粉体について、実施例２と同様の処理（たた
し、仕上げ焼結は、９５０℃Ｘ８ｈｒ）を施し、バルク
（円板）の超電導特性を測定したころ、■については、
Ｔｃ＝ ８３に、 Ｊｃ＝ ４０Ａ／ｃｍ２．■につい
ては、Ｔｃ＝８８８． Ｊｃ＝ １５０Ａ／ｃｍ２、■
については、Ｔｃ＝ ９２８． Ｊｃ＝ ４００Ａ／ｃ
ｍ２を示した。すなわち、本例の結果は実施例１の本発
明法による粉体からの焼結体の特性には及ばないものの
、同側中の従来法粉体からの焼結体の特性よりははるか
に優れたものてあった。これは、本例のような手法、換
言すればハイブリッドプラズマを用いず高周波プラズマ
のみの使用によっても優秀な焼結体を製造するための粉
体が得られることを示す。この理由は、本例のようなや
やパワーの小さい熱プラズマては極めて微細な粉体を得
るには至らないが、そうであっても高温加熱された後の
凝固時間が非常に短いために粒間ならびに粒内の成分偏
析が極めて小さくなり、従ってこの粉体を分級もしくは
再粉砕等の手法にて微細粉体側を選択的に取り出すこと
によって焼結体の均一・緻密化が図られることによる。These three types of powder were subjected to the same treatment as in Example 2 (sintering and final sintering at 950°C for 8 hours) and the superconducting properties of the bulk (disk) were measured.
Tc=83, Jc=40A/cm2. For ■, Tc=888. Jc = 150A/cm2, ■
For, Tc=928. Jc=400A/c
m2 was shown. In other words, although the results of this example are not as good as the properties of the sintered body made from the powder produced by the method of the present invention in Example 1, they are far superior to the properties of the sintered body made from the powder produced by the conventional method on the same side. There was something there. This shows that powder for producing an excellent sintered body can be obtained even by the method of this example, in other words, by using only high-frequency plasma without using hybrid plasma. The reason for this is that although it is not possible to obtain extremely fine powder using a thermal plasma with a rather low power as in this example, even if it is, the solidification time after being heated to a high temperature is very short, so it is difficult to obtain particles. This is due to the fact that the segregation of components between and within the grains is extremely small, and by selectively extracting the fine powder side using methods such as classification or re-grinding, the sintered body can be made uniform and dense. .
本例の方法は、プラズマ装置が簡便なものでよいため、
工業的には充分採用され得るものである。The method of this example requires only a simple plasma device;
It can be fully adopted industrially.
（発明の効果）
本発明によれば
■原料に関し従来技術より制限が少ないので、多種類の
原料選択ができるので製造そのものが容易になる。また
、製造コスト低減ができる。(Effects of the Invention) According to the present invention, (1) There are fewer restrictions on raw materials than in the prior art, and a wide variety of raw materials can be selected, making production itself easier. Furthermore, manufacturing costs can be reduced.
■安定した高い臨界温度と高い臨界電流密度とを兼備す
る超電導物質の製造が可能となるので超電導技術の広範
囲の実用の途を開くものであり、産業上益するところ多
大である。■Since it becomes possible to produce superconducting materials that have both stable and high critical temperatures and high critical current densities, this opens the door to a wide range of practical applications of superconducting technology, and has great industrial benefits.
第１図は本発明に用いられたセラミックス系超電導物質
微粉製造装置の一例を示す装置構成図である。
！・・・原料貯蔵箱、２・・・原料切出し装置、３・・
・原籾投入装置、４・・・直流プラズマガン、５・・・
直流プラズマ、６・・・直流プラズマ合体流、７・・・
高周波プラズマワークコイル、８・・・高周波プラズマ
、９・・・ハイブリッド炉、ｌＯ・・・冷却または反応
ガス吹込み孔、１１−・・粉体回収装置。FIG. 1 is an apparatus configuration diagram showing an example of an apparatus for producing fine ceramic superconducting material powder used in the present invention. ! ...raw material storage box, 2...raw material cutting device, 3...
・Raw rice charging device, 4...DC plasma gun, 5...
DC plasma, 6... DC plasma combined flow, 7...
High frequency plasma work coil, 8... High frequency plasma, 9... Hybrid furnace, lO... Cooling or reaction gas blowing hole, 11-... Powder recovery device.
Claims (7)
蒸発させる工程と、前記蒸発した原料を冷却して凝固さ
せて平均粒径１ミクロン以下の微粉として回収する工程
とから構成されることを特徴とするセラミックス系超電
導材料の製造方法。(1) It is characterized by comprising a step of heating the raw material of the ceramic superconducting material to high temperature and evaporating it, and a step of cooling and solidifying the evaporated raw material and recovering it as a fine powder with an average particle size of 1 micron or less. A method for manufacturing a ceramic superconducting material.
蒸発させる工程が、熱プラズマを用いることを特徴とす
る特許請求の範囲第１項記載の方法。(2) The method according to claim 1, wherein the step of heating and vaporizing the raw material of the ceramic superconducting material at a high temperature uses thermal plasma.
蒸発させる工程が、直流プラズマおよび高周波プラズマ
を組み合わせたハイブリッドプラズマを用いることを特
徴とする特許請求の範囲第１項記載の方法。(3) The method according to claim 1, wherein the step of heating and vaporizing the raw material of the ceramic superconducting material at a high temperature uses a hybrid plasma that is a combination of direct current plasma and high frequency plasma.
蒸発させる工程と、前記蒸発した原料を冷却して凝固さ
せて平均粒径１ミクロン以下の微粉として回収する工程
と、前記微粉をそのまま成形するかあるいは中空容器に
充填して所要の加工および／もしくは熱処理を行う工程
と、仕上げ焼結を行う工程とから構成されることを特徴
とするセラミックス系超電導材料の製造方法。(4) A step of heating the raw material of the ceramic superconducting material to a high temperature and evaporating it; a step of cooling and solidifying the evaporated raw material and recovering it as a fine powder with an average particle size of 1 micron or less; and molding the fine powder as it is. A method for producing a ceramic superconducting material, comprising the steps of: filling the material into a hollow container and subjecting it to necessary processing and/or heat treatment; and finishing sintering.
蒸発させる工程が、熱プラズマを用いることを特徴とす
る特許請求の範囲第４項記載の方法。(5) The method according to claim 4, wherein the step of heating and vaporizing the raw material of the ceramic superconducting material at a high temperature uses thermal plasma.
蒸発させる工程が、直流プラズマおよび高周波プラズマ
を組み合わせたハイブリッドプラズマを用いることを特
徴とする特許請求の範囲第４項記載の方法。(6) The method according to claim 4, wherein the step of heating and vaporizing the raw material of the ceramic superconducting material at a high temperature uses a hybrid plasma that is a combination of direct current plasma and high frequency plasma.
し装置と、高周波プラズマ発生装置と、前記高周波プラ
ズマ発生装置のワークコイルの中心軸と複数の直流プラ
ズマ流の合流部が一致するように配設した複数の直流プ
ラズマ発生装置と、前記セラミックス系超電導物質の原
料を前記複数の直流プラズマの合流部に送給する装置と
、プラズマ加熱により蒸発した前記原料を冷却凝固せし
めて回収する装置とから構成されることを特徴とするセ
ラミックス系超電導材料の製造装置。(7) A device for storing and cutting raw materials for ceramic superconducting materials, a high-frequency plasma generator, and a central axis of a work coil of the high-frequency plasma generator arranged so that the confluence of the plurality of DC plasma flows coincides with the central axis of the work coil of the high-frequency plasma generator. It is comprised of a plurality of DC plasma generators, a device that feeds the raw material of the ceramic superconducting material to the confluence of the plurality of DC plasmas, and a device that cools, solidifies, and recovers the raw material evaporated by plasma heating. A manufacturing device for ceramic superconducting materials characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62249921A JPH0193403A (en) | 1987-10-05 | 1987-10-05 | Production of ceramic-based superconducting material and apparatus therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62249921A JPH0193403A (en) | 1987-10-05 | 1987-10-05 | Production of ceramic-based superconducting material and apparatus therefor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0193403A true JPH0193403A (en) | 1989-04-12 |
Family
ID=17200167
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62249921A Pending JPH0193403A (en) | 1987-10-05 | 1987-10-05 | Production of ceramic-based superconducting material and apparatus therefor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0193403A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0397655A (en) * | 1989-09-07 | 1991-04-23 | Dowa Mining Co Ltd | Production of sintered body of perovskite type copper-containing oxide superconductor |
| US5166474A (en) * | 1988-09-02 | 1992-11-24 | Semiconductor Energy Laboratory Co., Ltd. | Superconducting device |
| JP2002347006A (en) * | 2001-05-24 | 2002-12-04 | Koji Yumoto | Arrangement of saw teeth |
-
1987
- 1987-10-05 JP JP62249921A patent/JPH0193403A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5166474A (en) * | 1988-09-02 | 1992-11-24 | Semiconductor Energy Laboratory Co., Ltd. | Superconducting device |
| JPH0397655A (en) * | 1989-09-07 | 1991-04-23 | Dowa Mining Co Ltd | Production of sintered body of perovskite type copper-containing oxide superconductor |
| JP2002347006A (en) * | 2001-05-24 | 2002-12-04 | Koji Yumoto | Arrangement of saw teeth |
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