JP2642644B2 - Method for producing oxide-based superconducting wire - Google Patents
Method for producing oxide-based superconducting wireInfo
- Publication number
- JP2642644B2 JP2642644B2 JP62280450A JP28045087A JP2642644B2 JP 2642644 B2 JP2642644 B2 JP 2642644B2 JP 62280450 A JP62280450 A JP 62280450A JP 28045087 A JP28045087 A JP 28045087A JP 2642644 B2 JP2642644 B2 JP 2642644B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- sintered body
- oxide
- composite
- wire
- 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
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/60—Superconducting electric elements or equipment; Power systems integrating superconducting elements or equipment
Description
【発明の詳細な説明】 「産業上の利用分野」 この発明は、超電導マグネットコイルや電力輸送線通
の超電導機器に用いられる超電導線の製造方法に関す
る。Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a superconducting wire used for a superconducting magnet coil and a superconducting device through a power transport line.
「従来の技術」 最近に至り、常電導状態から超電導状態へ遷移する臨
界温度（Tc）が液体窒素温度以上の値を示す酸化物系の
超電導材料が種々発見されている。"Prior art" Recently, various oxide-based superconducting materials having a critical temperature (Tc) at which a transition from a normal conducting state to a superconducting state has a value equal to or higher than the liquid nitrogen temperature have been discovered.
この種の酸化物系超電導材料は、一般式Ａ−Ｂ−Cu−
Ｏ（ただし、ＡはLa,Ce,Yb,Sc,Er等の周期率表第III a
族元素の１種以上を示し、ＢはBa,Sr等の周期率表第II
a族元素の１種以上を示す）で示されるものである。そ
して、この種の酸化物系超電導体を製造するには、前記
第III a族元素を含む粉末と第II a族元素を含む粉末と
酸化銅粉末とを混合して混合粉末を作製し、この混合体
を所定の形状に成形した後に、得られた成形体に熱処理
を施し、各元素を固相反応させて超電導物質を生成せし
めることにより製造するようにしている。This type of oxide-based superconducting material has the general formula AB-Cu-
O (where A is the periodic table of La, Ce, Yb, Sc, Er, etc., IIIa
B represents one or more group elements, and B is the periodic table of Ba, Sr, etc.
which represents at least one group a element). Then, in order to manufacture this type of oxide superconductor, a powder containing the group IIIa element, a powder containing the group IIa element, and a copper oxide powder were mixed to prepare a mixed powder. After the mixture is formed into a predetermined shape, the resulting formed body is subjected to a heat treatment to cause a solid-phase reaction of each element to produce a superconducting material.
また、前記Ａ−Ｂ−Ｃ−Ｄ系の超電導体を具備する超
電導線を製造する方法として、従来前記混合粉末を金属
管に充填するか、あるいは混合粉末に熱処理を施して得
た超電導粉末を金属管に充填し、充填後にダイスなどを
用いて金属管を引抜加工して所望の直径の線材を得、こ
の線材に熱処理を施して内部の圧粉成形体の各元素を固
相反応させ、金属管の内部に超電導物質を生成させるこ
とにより超電導線を得る方法が知られている。Further, as a method for manufacturing a superconducting wire having the ABCD-based superconductor, a superconducting powder obtained by conventionally filling a metal tube with the mixed powder or subjecting the mixed powder to a heat treatment is used. Filling the metal tube, after filling the metal tube using a die or the like to obtain a wire having a desired diameter, performing a heat treatment on this wire to cause a solid-phase reaction of each element of the compacting body inside, There is known a method of obtaining a superconducting wire by generating a superconducting substance inside a metal tube.
「発明が解決しようとする問題点」 ところで、前記超電導線の製造方法にあっては、ダイ
スを用いた引抜加工により金属管を縮径して混合粉末を
圧粉する関係から、引抜加工に際し断線しない程度に加
工を施す必要があり、よって加工率に限界を生じること
から粉末の圧密度を十分に高めることができないという
問題がある。そして、これにより圧密度が十分でない圧
粉成形体に熱処理を施して焼結することになるため、得
られた超電導線にあっては、各元素の固相反応が十分に
なされていない傾向があり、よって優れた臨界電流特性
を有する超電導線が得られないという問題がある。"Problems to be Solved by the Invention" By the way, in the method for manufacturing a superconducting wire, since the diameter of the metal tube is reduced by drawing using a die and the mixed powder is compacted, the wire is disconnected at the time of drawing. Therefore, there is a problem that it is not possible to sufficiently increase the compaction density of the powder because the working rate must be reduced to such an extent that the working rate is limited. Then, since the green compact having insufficient compaction density is subjected to heat treatment and sintered, the obtained superconducting wire has a tendency that the solid-state reaction of each element is not sufficiently performed. Therefore, there is a problem that a superconducting wire having excellent critical current characteristics cannot be obtained.
また、前述のように圧密度が十分でない圧粉成形体を
焼結して超電導線を製造した場合、超電導体内部の気孔
率が比較的大きいため、超電導線の曲げ強度が不足する
など、強度面での不満が大きいという問題がある。そし
て、これにより前記超電導線超電導マグネットの巻線用
などとして巻胴に巻回しようとする場合、超電導線中の
超電導体にクラックが入り易くなり、よって超電導特性
が著しく低下する恐れを生ずる。In addition, when a superconducting wire is manufactured by sintering a green compact having insufficient compaction density as described above, since the porosity inside the superconductor is relatively large, the bending strength of the superconducting wire is insufficient. There is a problem that dissatisfaction in terms of size is large. Thus, when the superconducting wire is to be wound around a winding drum for use in winding the superconducting magnet, the superconductor in the superconducting wire is liable to crack, and the superconducting properties may be significantly reduced.
この発明は前記問題に鑑みてなされたもので、その目
的とするところは、焼結密度が十分に高く、よって優れ
た臨界電流密度を発揮するとともに高い機械強度を示す
酸化物系超電導線の製造方法を提供することにある。The present invention has been made in view of the above problems, and an object thereof is to produce an oxide-based superconducting wire having a sufficiently high sintering density and thus exhibiting an excellent critical current density and exhibiting high mechanical strength. It is to provide a method.
「問題点を解決するための手段」 この発明の酸化物系超電導線の製造方法では、酸化物
系超電導粉末と酸化物系超電導体の前駆体粉末の少なく
とも一方を圧分成形して理論密度が60％以上の圧密度の
圧粉成形体を得、次いでこの圧粉成形体を焼結して理論
度が70％以上の圧密度の中間焼結体を得、その後この中
間焼結体を圧密する際に、この中間焼結体を金属シース
内に充填して複合体を形成し、次いで、複数のダイスを
ダイスの加工面どうしを対向させてそれらのダイス間の
間隙を拡げるか縮小する方向に相互に接近または離間自
在に設け、かつ、各ダイスを前記ダイス間の間隙まわり
に回転自在に設けたロータリースウェージング装置を用
い、このロータリースウェージング装置の間隙に沿って
前記複合体を通過させて前記ダイスを複合体に打ち付け
て複合体を鍛造して縮径加工し、その後に焼結して理論
密度が90％以上の圧密度の焼結体を得ることを前記問題
点の解決手段とした。[Means for Solving the Problems] In the method for manufacturing an oxide-based superconducting wire of the present invention, at least one of the oxide-based superconducting powder and the precursor powder of the oxide-based superconductor is pressure-molded to obtain a theoretical density. Obtain a green compact with a compaction density of 60% or more, and then sinter this compact to obtain an intermediate sintered body with a theoretical density of 70% or more, and then compact the intermediate sintered body. In this case, the intermediate sintered body is filled in a metal sheath to form a composite, and then, a plurality of dies are made to face each other with the processing surfaces of the dies facing each other to increase or decrease the gap between the dies. Are provided so as to be close to or separated from each other, and each die is rotatably provided around a gap between the dies using a rotary swaging apparatus, and the composite is passed along the gap of the rotary swaging apparatus. Composite the above dies Forged complex was diameter reduction nailed in, then the theoretical density by sintering is a solution of the above problems to obtain a sintered body of 90% or more compaction degree.
以下、この発明の酸化物系超電導線の製造方法の一例
を図面を利用して詳しく説明する。Hereinafter, an example of a method for manufacturing an oxide superconducting wire of the present invention will be described in detail with reference to the drawings.
まず、出発物を調製して原料粉末を得る。この出発物
としては、酸化物系超電導粉末か、酸化物系超電導体の
前駆体粉末が用いられ、さらにはこれらの混合物も用い
られる。そして、超電導粉末を用いた場合にはこの粒径
等が調整されて原料粉末とされ、また前駆体粉末が用い
られた場合には後述するように各材料粉末が所定比に混
合され、かつ粒径等が調整されて原料粉末とされる。First, a starting material is prepared to obtain a raw material powder. As the starting material, an oxide-based superconducting powder or a precursor powder of an oxide-based superconductor is used, and a mixture thereof is also used. When the superconducting powder is used, the particle size and the like are adjusted to be a raw material powder, and when the precursor powder is used, each material powder is mixed at a predetermined ratio as described later, The diameter and the like are adjusted to obtain a raw material powder.
ここで、前記酸化物系超電導体とは、一般式Ａ−Ｂ−
Ｃ−Ｄ系（ただしＡは、Y,Sc,La,Ce,Pr,Nd,Pm,Sm,Eu,G
d,Tb,Dy,Ho,Er,Tm,Yb,Luなどの周期律表第III a族元素
のうち１種あるいは２種以上を示し、ＢはSr,Ba,Ca,Be,
Mg,Raなどの周期律表第II a族元素のうち１種あるいは
２種以上を示し、ＣはCu,Ag,Auの周期律表第I b族元素
とNbのうちCuあるいはCuを含む２種以上を示し、ＤはO,
S,Se,Te,Poなどの周期律表第VI b族元素およびF,Cl,Br
等の周期律表第VII b元素のうちＯあるいはＯを含む２
種以上を示す）として示されるものとされる。Here, the oxide-based superconductor has the general formula AB-
CD system (A is Y, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, G
d, Tb, Dy, Ho, Er, Tm, Yb, Lu, etc., represents one or more of the Group IIIa elements of the Periodic Table, and B represents Sr, Ba, Ca, Be,
One or more of the Group IIa elements of the periodic table, such as Mg and Ra, and C represents Cu, Cu, Ag, and Au of the Periodic Table of the Group Ib and Nb containing Cu or Cu among Nb. More than species, D is O,
S, Se, Te, Po, and other Group VIb elements of the periodic table and F, Cl, Br
Or 2 containing O in the elements of the periodic table VIIb
Species or more).
また、酸化物系超電導体の前駆体粉末とは、前記の酸
化物系超電導体を構成する元素を含む材料粉末を示すも
のとされ、この酸化物系超電導体の形成元素を含む材料
粉末としては、周期律表第II a族元素を含む粉末と周期
律表第III a族元素を含む粉末と酸化銅粉末などからな
る混合粉末、あるいはこの混合粉末を仮焼した後粉砕し
て得た粉末、さらには前記混合分粉末と仮焼粉末との混
合粉末などが用いられる。そして、ここで用いられる周
期律表第II a族元素粉末としては、Be,Sr,Mg,Ba,Raの各
元素の炭酸塩粉末、酸化物粉末、塩化物粉末、硫化物粉
末、フッ化物粉末などの化合物粉末あるいは合金粉末な
どがあり、なかでも粒径が３μｍ程度以下に調整された
炭酸塩粉末が好適に用いられる。また、周期律表第III
a族元素粉末としては、Sc,Y,La,Ce,Pr,Nd,Pm,Sm,Eu,Gd,
Tb,Dy,Ho,Er,Tm,Yb,Luの各元素が酸化物粉末、炭酸塩粉
末、塩化物粉末、硫化物粉末、フッ化物粉末などの化合
物粉末あるいは合金粉末などが用いられ、粒径５μｍ程
度以下に調整された酸化物粉末がより好適に用いられ
る。さらに、酸化銅粉末としては、CuO,Cu2O,Cu3O2,Cu4
O3などが用いられ、粒径３μｍ程度以下に調整されたCu
Oがより好適に用いられる。Further, the precursor powder of the oxide-based superconductor refers to a material powder containing the element constituting the oxide-based superconductor, and the material powder including the element forming the oxide-based superconductor includes: A powder containing a powder containing a Group IIa element of the Periodic Table and a powder containing a Group IIIa element of the Periodic Table and a copper oxide powder, or a powder obtained by calcining and then pulverizing this mixed powder, Further, a mixed powder of the mixed powder and the calcined powder is used. The powders of Group IIa elements of the periodic table used herein include carbonate powders, oxide powders, chloride powders, sulfide powders, and fluoride powders of the respective elements Be, Sr, Mg, Ba, and Ra. Among them, there is a compound powder or an alloy powder, and among them, a carbonate powder having a particle diameter adjusted to about 3 μm or less is suitably used. In addition, Periodic Table III
Group a element powders include Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd,
Each element of Tb, Dy, Ho, Er, Tm, Yb, Lu is a compound powder such as an oxide powder, a carbonate powder, a chloride powder, a sulfide powder, a fluoride powder, or an alloy powder, or the like. An oxide powder adjusted to about 5 μm or less is more preferably used. Further, as the copper oxide powder, CuO, Cu 2 O, Cu 3 O 2 , Cu 4
Cu with O 3 etc. adjusted to a particle size of about 3 μm or less
O is more preferably used.
なお、前記酸化物系超電導体の構成元素を含む材料粉
末を所定比に混合調整して原料粉末とするには、通常各
材料粉末を所定比に秤量混合する方法が取られるが、こ
の方法に限定されるものではなく、各元素をシュウ酸塩
として共沈せしめ、その沈殿物を加熱乾燥して粉末状の
混合物とし、これを原料粉末とする共沈法を用いてもよ
く、その場合には各元素の混合比をより正確に調整する
ことができる。また、前記必要な元素のアルコキシド化
合物、オキシケトン化合物、シクロペンタジエニル化合
物などを所定の比率で混合して混合液とし、この混合液
に水を加えて加水分解などしてゾル状にするとともに、
このゾル状の物質を加熱してゲル化し、このゲルをさら
に加熱して固相とした上で粉砕して混合粉末を得、これ
を原料粉末とするゾルゲル法を適用してもよい。In addition, in order to mix and adjust the material powder containing the constituent elements of the oxide-based superconductor at a predetermined ratio to obtain a raw material powder, a method of weighing and mixing the respective material powders at a predetermined ratio is generally employed. It is not limited, and each element may be coprecipitated as oxalate, and the precipitate may be heated and dried to form a powdery mixture, and a coprecipitation method using this as a raw material powder may be used. Can more accurately adjust the mixing ratio of each element. In addition, an alkoxide compound of the necessary element, an oxyketone compound, a cyclopentadienyl compound, and the like are mixed at a predetermined ratio to form a mixed solution, and water is added to the mixed solution to form a sol by hydrolysis and the like.
The sol-like substance may be heated to gel, and the gel may be further heated to a solid phase and pulverized to obtain a mixed powder, and the sol-gel method using the mixed powder as a raw material powder may be applied.
次に、前記原料粉末を500〜1000℃の温度で１〜100時
間、必要回数加熱して仮焼する。この仮焼処理が終了し
たならば、仮焼物をさらに粉砕して粒径を揃え、ラバー
プレス法などの静水圧により棒状に圧粉成形し、圧密度
が気孔率ゼロの理論密度に対し60％以上、好ましくは70
％近くの圧粉成形を得る。ここで、圧粉成形体の圧密度
を60％以上としたが、60％未満になると、後述する焼結
において得られる中間焼結体の圧密度が十分なものとな
らず、よって所望する特性を備えた超電導線を作製する
ことが困難となるからである。Next, the raw material powder is heated and calcined at a temperature of 500 to 1000 ° C. for 1 to 100 hours as needed. When this calcining process is completed, the calcined product is further pulverized to uniform particle size, and compacted into a rod by hydrostatic pressure such as a rubber press method, and the compact density is 60% of the theoretical density of zero porosity. Above, preferably 70
% Compaction is obtained. Here, the compaction density of the green compact is set to 60% or more. However, if the compaction density is less than 60%, the compaction density of the intermediate sintered body obtained in the sintering described later will not be sufficient, and the desired characteristics will be obtained. This is because it becomes difficult to produce a superconducting wire having
また、この場合に成形圧力は、仮焼物の種類、目的の
圧密度などに応じて定められるが、通常は1.5〜10ton/c
m2程度の範囲で定められる。なお、ここで行う粉砕物の
圧粉法は、前述の方法に限るものではなく、前記粉砕物
を所望の圧密度の圧粉成形体に加圧成形できる方法であ
れば、いかなる方法でも使用可能である。また、仮焼処
理と粉砕処理と圧粉処理などからなる一連の工程を１回
以上繰り返し行っても差し支えない。ここで、前記仮焼
処理は、混合粉末中に炭酸塩や炭素などの不純物が含ま
れている場合に、後工程の熱処理時に不要ガスが発生す
ることを阻止するためなどの処理とされる。In this case, the molding pressure is determined according to the type of the calcined material, the target pressure density, and the like.
defined by m 2 range of about. The compacting method of the pulverized material performed here is not limited to the method described above, and any method can be used as long as the method can press-mold the pulverized material into a green compact having a desired compaction density. It is. In addition, a series of steps including a calcination process, a pulverization process, a compacting process, and the like may be repeatedly performed once or more. Here, the calcination treatment is a treatment for preventing generation of unnecessary gas during a heat treatment in a later step when impurities such as carbonate and carbon are contained in the mixed powder.
次いで、前記棒状に成形体を酸素雰囲気中において80
0〜1100℃で１〜100時間加熱するとともに、加熱後に徐
冷する中間熱処理を行い、気孔率ゼロを理論密度に対し
70％以上、好ましくは85％近くの圧密度を有する棒状の
中間焼結体を得る。ここで、中間焼結体の圧密度を70％
以上としたが、70％未満になると、後述するロータリー
スウェージング装置による縮径加工を行っても十分な圧
密度が得られず、よって所望する特性を備えた超電導線
を作製することが困難となるからである。Next, the molded body in the shape of a rod is
While heating at 0 to 1100 ° C for 1 to 100 hours, perform an intermediate heat treatment of gradually cooling after heating, and set the porosity to zero with respect to the theoretical density.
A rod-shaped intermediate sintered body having a consolidation density of 70% or more, preferably close to 85% is obtained. Here, the pressure density of the intermediate sintered body is 70%
However, if it is less than 70%, a sufficient pressure density cannot be obtained even if the diameter is reduced by a rotary swaging apparatus described later, and it is difficult to produce a superconducting wire having desired characteristics. Because it becomes.
次いで、第１図に示すように前述の如く作製された中
間焼結体１を金属製の管体２に充填して複合体３を作成
る。前記管体２は、Cu,Ag,Alあるいはこれらの合金また
はステンレスなどの金属材料から形成されている。な
お、管体２の構成材料は塑性加工可能なものであれば金
属材料に限らないが、熱処理時に中間焼結体１から酸素
を奪わないような非酸化性の材料を選択する必要があ
り、したがって貴金属あるいは貴金属を含有する合金な
どが好適に用いられ、さらには歓管体の内周面に非酸化
性の材料がらなる被覆層を形成したものも使用される。Next, as shown in FIG. 1, the intermediate sintered body 1 produced as described above is filled in a metal tube 2 to form a composite 3. The tube 2 is made of a metal material such as Cu, Ag, Al, an alloy thereof, or stainless steel. The constituent material of the tube 2 is not limited to a metal material as long as it can be plastically processed. However, it is necessary to select a non-oxidizing material that does not deprive the intermediate sintered body 1 of oxygen during heat treatment. Therefore, a noble metal or an alloy containing a noble metal is suitably used, and further, a material in which a coating layer made of a non-oxidizing material is formed on the inner peripheral surface of the funnel is also used.
次いで、第１図に示したロータリースウェージング装
置Ａにより前記複合体３に縮径加工を施し、管体２を介
して中間焼結体１を圧縮する。ここで、前記ロータリー
スウェージング装置Ａは、図示略の駆動装置によって移
動自在に設けられた複数のダイス４を備えてなるもので
ある。これらダイス４は、複合体３をその長さ方向に移
動させる際の移動空間の周囲に、この移動空間を囲むよ
うに設けられたもので、前記移動空間と直角な方向（第
１図に示す矢印ａ方向）に移動自在に、かつ、移動空間
の周回り方向（第１図に示す矢印ｂ方向）に回転自在に
保持されている。また、各ダイス４の内面には、前記複
合体３を縮径加工するためのテーパ面4aが形成されてい
て、各ダイス４のテーパ面4aで囲む間隙が先窄まり状と
なるようになっている。Next, the composite 3 is subjected to diameter reduction by the rotary swaging apparatus A shown in FIG. 1, and the intermediate sintered body 1 is compressed through the tube 2. Here, the rotary swaging device A includes a plurality of dies 4 movably provided by a drive device (not shown). These dies 4 are provided so as to surround the moving space when moving the complex 3 in the length direction thereof, and surround the moving space, and a direction perpendicular to the moving space (shown in FIG. 1). It is held movably in the direction of arrow a) and rotatable in the circumferential direction of the moving space (direction of arrow b shown in FIG. 1). Further, a tapered surface 4a for reducing the diameter of the composite 3 is formed on the inner surface of each die 4, and the gap surrounded by the tapered surface 4a of each die 4 becomes tapered. ing.
このようなロータリースウェージング装置Ａにより前
記複合体３を縮径するには、装置Ａを作動させるととも
に、第１図に示すように複合体３の一端をダイス４…の
間の間隙に押し込む。ここで、前記ダイス４…第１図の
矢印ａ方向に所定間隔往復移動しつつ回転しているた
め、複合体３は一端側から順次鍛造されて縮径され、第
１図中２点鎖線に示す線径まで縮径されて線材５が得ら
れる。この縮径加工にあっては、回転しつつ往来運動す
る複数のダイスによって複合体３を鍛造しつつ縮径する
ため、縮径加工中の複合体３に断線をもたらすことなく
大きな加工率で縮径加工することができ、さらに中間焼
結体１を圧縮して高度に圧密化することができる。In order to reduce the diameter of the composite 3 by such a rotary swaging apparatus A, the apparatus A is operated and one end of the composite 3 is pushed into the gap between the dies 4 as shown in FIG. Here, the dies 4 are rotating while reciprocating at predetermined intervals in the direction of arrow a in FIG. 1, so that the composite 3 is forged sequentially from one end side and reduced in diameter, and is shown by a two-dot chain line in FIG. The wire is reduced to the wire diameter shown to obtain the wire 5. In this diameter reduction processing, the composite 3 is reduced in diameter while forging the composite 3 by a plurality of dies that rotate and move forward and backward, so that the composite 3 during the diameter reduction is reduced at a large processing rate without causing disconnection. The intermediate sintered body 1 can be worked to a large diameter and can be highly compacted.
前記縮径加工終了後、得られた線材５の線径が未だ所
望する線径に達していない場合には、先のロータリース
ウェージング装置Ａに設けられたダイスＡよりもさらに
小さい成形空隙を有するダイスを用い、前記線材５に再
度ロータリースウェージング装置による縮径加工を施
し、所望する線径の線材を得る。When the wire diameter of the obtained wire 5 has not yet reached the desired wire diameter after the completion of the diameter reduction processing, the wire 5 has a smaller forming gap than the die A provided in the rotary swaging apparatus A. Using a die, the wire 5 is again subjected to a diameter reducing process by a rotary swaging device to obtain a wire having a desired wire diameter.
前記のように、１回あるいは２回以上の縮径加工を行
って複合体３を所望する線径にまで縮径し、中間焼結体
１を圧縮したならば、縮径後の線材に以下に説明する処
理を施して超電導線を製造する。As described above, the diameter of the composite 3 is reduced to a desired wire diameter by performing diameter reduction processing once or twice or more, and the intermediate sintered body 1 is compressed. To produce a superconducting wire.
まず、前記線材５から外側の金属シースとなっている
管体部分を除去し、これにより圧縮された中間焼結体１
を露出させる。ここで、金属シースを除去する方法とし
ては、酸、アルカリなどの処理液中に線材５を浸漬さ
せ、金属シースのみを上記処理液中に溶解せしめる化成
処理法が好適に採用される。すなわち、金属シースに
銅、銀あるいはこれらの合金を用いた場合には希硝酸等
の酸を、またアルミニウムを用いた場合には苛性ソーダ
等のアルカリ、さらにステンレスを用いた場合には王水
を用い、これにより金属シースを溶解して線材５から除
去し、中間焼結体１を露出せしめる。そして、このよう
な除去操作の後には、速やかに中間焼結体１を水洗する
か、あるいは中和処理を施した後水洗するのが、作製す
る超電導体への不純物の混入を防止するとともに、作業
上設備等の腐食を防止するうえで望ましい。なお、この
ような化成処理に用いられる処理液としては前記種類に
限られることなく、金属シースに材質に応じて例えば塩
酸、硫酸、リン酸などや、これらの希釈液などが適宜さ
れる。First, the tubular portion serving as the outer metal sheath is removed from the wire 5, and the compressed intermediate sintered body 1 is thereby removed.
To expose. Here, as a method for removing the metal sheath, a chemical conversion treatment method in which the wire 5 is immersed in a treatment liquid such as an acid or an alkali and only the metal sheath is dissolved in the treatment liquid is suitably employed. In other words, when copper, silver or their alloys are used for the metal sheath, an acid such as dilute nitric acid is used, when aluminum is used, an alkali such as caustic soda is used, and when stainless steel is used, aqua regia is used. Thus, the metal sheath is melted and removed from the wire 5 to expose the intermediate sintered body 1. After such a removing operation, immediately washing the intermediate sintered body 1 with water, or performing a neutralization treatment and then washing with water, prevents impurities from being mixed into the superconductor to be manufactured, and It is desirable in order to prevent corrosion of facilities and the like in operation. In addition, the treatment liquid used in such a chemical conversion treatment is not limited to the above-described type, and for example, hydrochloric acid, sulfuric acid, phosphoric acid, or the like, or a diluent thereof, may be appropriately used depending on the material of the metal sheath.
また、前記金属シースの除去には、切削加工法を用い
る方法も考えられるが、中間焼結体１が細径の場合、こ
の切削加工法を用いると除去操作時に中間焼結体１が断
線してしまうことなどの不都合を生じるおそれがあるた
め、この例では、中間焼結体１に前述の不都合が生じに
くい化成処理法を採用した。しかし、折曲のおそれが少
ない場合には、切削加工法を行って金属シースを除去し
ても差し支えなく、さらには切削加工で金属シースを除
去する方法と金属シースを化学的に除去する方法を併用
しても良い。In order to remove the metal sheath, a method using a cutting method is also conceivable. However, when the intermediate sintered body 1 has a small diameter, the intermediate sintered body 1 is disconnected during the removing operation by using the cutting method. Therefore, in this example, a chemical conversion treatment method is used for the intermediate sintered body 1 in which the above-mentioned inconvenience is unlikely to occur. However, when there is little risk of bending, the metal sheath can be removed by performing a cutting method.Furthermore, a method of removing the metal sheath by cutting and a method of chemically removing the metal sheath are available. You may use together.
次に、このように露出せしめられた中間焼結体１を加
熱して焼結処理を施し、この中間焼結体１を酸化物系超
電導体とするともに、気孔率ゼロの理論密度に対し90％
以上、好ましくは95％近くの圧密度を有する焼結体とす
る。ここで、得られる焼結体の圧密度が90％未満である
と、酸化物系超電導体としての臨界電流密度の向上効果
が十分でなく、さらには機械的強度も十分でないなどの
理由により、本発明によって得られる超電導体（超電導
線）としてはい不適なものとされる。Next, the exposed intermediate sintered body 1 is heated and subjected to a sintering treatment to make the intermediate sintered body 1 an oxide-based superconductor and a 90% porosity theoretical density. %
As described above, the sintered body preferably has a pressure density of about 95%. Here, when the pressure density of the obtained sintered body is less than 90%, the effect of improving the critical current density as an oxide-based superconductor is not sufficient, and further, the mechanical strength is not sufficient. The superconductor (superconducting wire) obtained by the present invention is considered to be unsuitable.
そして、前記焼結処理の条件としては、酸素雰囲気中
にて800〜1100℃で１〜100時間程度加熱し、その後50〜
500℃/H程度の冷却速度で徐冷するものとされる。なお
ここで、徐冷処理の途中に400〜600℃の温度範囲で所定
時間保持する処理を行い、酸化物系超電導体の結晶構造
が正方晶から斜方晶に変態することを促進するようにし
ても良い。And the conditions of the sintering treatment are as follows: heating in an oxygen atmosphere at 800 to 1100 ° C. for about 1 to 100 hours;
Slow cooling is performed at a cooling rate of about 500 ° C / H. Here, during the slow cooling process, a process of holding for a predetermined time in a temperature range of 400 to 600 ° C. is performed so as to promote the transformation of the crystal structure of the oxide superconductor from tetragonal to orthorhombic. May be.
このような焼結処理により、上記中間焼結体中１の各
構成元素どうしが互いに十分固相反応を起こすととも
に、中間焼結体１の表面が露出せしめられていることに
よってこの表面全体から中間焼結体１内部に酸素が効率
よく拡散され、これにより中間焼結体１は、その全長に
亘って良好な結晶構造を有し、よって均一な超電導特性
を示す超電導線となる。また、超電導体とされた焼結体
が90％以上の圧密度を有していることから、全体として
高い臨界電流密度を示すとともに、機械的強度にも優れ
た酸化物系超電導線が得られる。By such a sintering process, the respective constituent elements in the intermediate sintered body 1 cause a sufficient solid-phase reaction with each other, and since the surface of the intermediate sintered body 1 is exposed, the intermediate surface Oxygen is efficiently diffused into the sintered body 1, whereby the intermediate sintered body 1 has a good crystal structure over its entire length, and thus becomes a superconducting wire exhibiting uniform superconducting characteristics. In addition, since the superconductor has a sintered body having a pressure density of 90% or more, an oxide superconducting wire having a high critical current density as a whole and excellent mechanical strength can be obtained. .
なお、このような酸化物系超電導線には、必要に応じ
コーティング処理を施して保護コート層を形成してもよ
い、この保護コート層の形成材料としては、例えば錫、
鉛等の低融点金属、あるいは半田等の合金などが好適に
用いられる。そして、この保護コート層の形成方法とし
ては、例えば電気メッキ、溶融メッキ、半田メッキなど
の方法が好適に用いられる。また、他の方法として、前
記低融点金属の粉末あるいは前記合金粉末を酸化物系超
電導線の表面に所定の厚さで付着させた後、前記粉末を
焼結させる方法も用いることができる。このようにして
保護コート層を形成すれば、酸化物系超電導線の良好な
超電導特性を長期間に亘って安定化させることが可能と
なる。In addition, such an oxide-based superconducting wire may be subjected to a coating treatment as necessary to form a protective coat layer. Examples of a material for forming the protective coat layer include tin,
A low melting point metal such as lead or an alloy such as solder is preferably used. As a method for forming the protective coat layer, for example, a method such as electroplating, hot-dip plating, or solder plating is suitably used. Further, as another method, a method of attaching the powder of the low melting point metal or the alloy powder to a surface of the oxide-based superconducting wire at a predetermined thickness, and then sintering the powder can also be used. By forming the protective coating layer in this manner, it becomes possible to stabilize the good superconducting characteristics of the oxide superconducting wire over a long period of time.
このような超電導線の製造方法によれば、圧密度60％
以上とした圧粉成形体を鍛造法による縮径加工により十
分に圧縮して圧密度70％以上の中間焼結体とし、さらに
この中間焼結体を焼結せしめて圧密度が90％以上の焼結
体とするため、得られた超電導線は圧密度が高く、気孔
率が低く、機械強度も高いものとなる。したがって、こ
の超電導線は、その全長に亘って良好な結晶構造を示す
とともに均一な超電導特性を呈し、よって高い臨界電流
密度を示すとともに優れた機械的強度を示すものとな
る。そして、これにより前記超電導線は、例えば超電導
あマグネット用の巻線とした場合でもクラックを生じる
ことなく巻回することができるものとなる。According to such a method of manufacturing a superconducting wire, the pressure density is 60%
The green compact formed as described above is sufficiently compressed by a diameter reduction process using a forging method to form an intermediate sintered body having a compaction density of 70% or more. The intermediate sintered body is further sintered to have a compaction density of 90% or more. Since it is a sintered body, the obtained superconducting wire has high pressure density, low porosity, and high mechanical strength. Therefore, this superconducting wire exhibits a good crystal structure over its entire length and exhibits uniform superconducting properties, and thus exhibits a high critical current density and excellent mechanical strength. Thus, the superconducting wire can be wound without causing cracks even when it is used as, for example, a winding for a superconducting magnet.
「実施例」 純度99.9％以上で粒径４μｍのY2O3粉末と、同じ純度
99.9％以上で粒径１μｍのBaCO3粉末およびCuO粉末を、
Y:Ba:Cu＝1:2:3（モル比）となるように、秤量し混合し
て原料粉末を得るとともに、この原料粉末を酸素気流中
において900℃で24時間加熱する仮焼処理を行った。And Y 2 O 3 powder particle size 4μm in "Examples" purity of 99.9% or more, the same purity
BaCO 3 powder and CuO powder with a particle size of 1 μm with 99.9% or more,
Y: Ba: Cu = 1: 2: 3 (molar ratio) and weighed and mixed to obtain a raw material powder, and a calcining treatment of heating this raw material powder at 900 ° C for 24 hours in an oxygen stream. went.
次に、この仮焼体を粉砕して粉末を得、この粉末をラ
バープレス法により2500Kg/cm2の成形圧で圧粉し、圧密
度約62％の圧粉成形体を得た。Next, the calcined body was pulverized to obtain a powder, and the powder was compacted by a rubber press method at a molding pressure of 2500 kg / cm 2 to obtain a compact having a compact density of about 62%.
次いで、この圧粉成形体を酸素気流中において900℃
で24時間加熱し、その後徐冷してY1Ba2Cu3O7-X（ただ
し、０≦ｘ≦５）の組成からなり、圧密度約72％の丸棒
状の中間終結体を得た。Next, the green compact is heated at 900 ° C. in an oxygen stream.
For 24 hours, and then gradually cooled to obtain a round rod-shaped intermediate end product having a composition of Y 1 Ba 2 Cu 3 O 7-X (where 0 ≦ x ≦ 5) and a pressure density of about 72%. .
次いで、前記中間焼結体を外径10mm、内径7mmの銀製
の管体に充填して複合体とし、さらにこの複合体をロー
タリースウェージング装置により冷間で鍛造しつつ段階
的に縮径加工を施して外径1.5mmの線材とした。なお、
複合体を段階的に縮径するにあたっては、ダイス間の空
隙が異なるダイスを複数用意し、１パスの断面減少率を
約20％に設定するとともに加工速度を1m/分とし、複数
回鍛造操作を行って縮径加工を施した。Next, the intermediate sintered body was filled into a silver tube having an outer diameter of 10 mm and an inner diameter of 7 mm to form a composite, and the composite was further subjected to stepwise diameter reduction while being cold forged by a rotary swaging apparatus. To give a wire rod with an outer diameter of 1.5 mm. In addition,
To reduce the diameter of the composite stepwise, prepare multiple dies with different gaps between dies, set the cross-sectional reduction rate of one pass to about 20%, set the processing speed to 1 m / min, and perform multiple forging operations. To reduce the diameter.
以上の加工においては、所望する線径に至るまで断線
などのトラブルを生じることなく加工することができ
た。In the above processing, processing could be performed without causing troubles such as disconnection up to a desired wire diameter.
次いで、この線材を硝酸中に含侵させて銀製のシース
を溶解除去し、圧縮され小径となった中間焼結体を露出
させ、さらにこの中間焼結体を酸素気流中にて890℃で1
7時間加熱焼結し、圧密度約92％の焼結体を得た。Next, the wire rod was impregnated with nitric acid to dissolve and remove the silver sheath, exposing the compressed intermediate sintered body having a reduced diameter, and further sintering the intermediate sintered body at 890 ° C. in an oxygen stream at 890 ° C.
Heat sintering was performed for 7 hours to obtain a sintered body having a compact density of about 92%.
その後、その焼結体を100℃/H程度で室温まで除冷
し、中間焼結体の全線に亘って酸化物系系超電導体を生
成させ、超電導線を得た。Thereafter, the sintered body was cooled to room temperature at about 100 ° C./H, and an oxide-based superconductor was generated over the entire wire of the intermediate sintered body to obtain a superconducting wire.
このようにして製造された酸化物系超電導線は、 臨界温度 91K 臨界電流密度 約11000A/cm2（77Kにおいて）を示し
た。The oxide-based superconducting wire thus produced exhibited a critical temperature of 91 K, a critical current density of about 11,000 A / cm 2 (at 77 K).
これに対し、原料粉末を圧粉して圧密度を理論密度の
50％、55％に設定した圧粉成形体（比較冷１、２）を作
製した。これらの圧粉成形体を前記実施例と同様にそれ
ぞれ中間焼結体とし、さらに複合体とした後、ロータリ
ースウェージング装置により鍛造し縮径した。次いで、
縮径して得られた線材の金属シースを溶解除去して中間
焼結体を露出させた後、この中間焼結体に前記実施例と
同一条件で熱処理を施して酸化物系超電導線を得た。On the other hand, the raw material powder is compacted
Dust compacts (comparative cold 1 and 2) were set at 50% and 55%. Each of these compacts was formed into an intermediate sintered body in the same manner as in the above example, and further formed into a composite, then forged by a rotary swaging apparatus and reduced in diameter. Then
After dissolving and removing the metal sheath of the wire obtained by reducing the diameter to expose the intermediate sintered body, the intermediate sintered body is subjected to a heat treatment under the same conditions as in the above embodiment to obtain an oxide superconducting wire. Was.
これら酸化物系超電導線の焼結密度（圧密度）と臨界
電流密度を以下の第１表に示す。The sintering density (pressure density) and critical current density of these oxide superconducting wires are shown in Table 1 below.
前記実施例の試料と前記第１表の試料の比較から、本
発明による超電導線は機械強度が高く臨界電流密度も優
れていることが明らかとなった。 From the comparison between the sample of the above example and the sample of Table 1, it became clear that the superconducting wire according to the present invention has high mechanical strength and excellent critical current density.
「発明の効果」 以上説明したように、この発明の酸化物系超電導線の
製造方法は、酸化物系超電導粉末と酸化物超電導体の前
駆体粉末の少なくとも一方を圧粉成形して理論密度が60
％以上の圧密度の圧粉成形体を得、次いでこの圧粉成形
体を焼結して理論度が70％以上の圧密度の中間焼結体を
得、その後この中間焼結体を圧密する際に、中間焼結体
を金属シース内に充填して複合体を形成し、複数のダイ
スをダイスの加工面どうしを対向させてそれらのダイス
間の間隙を拡げるか縮小する方向に相互に接近または離
間自在に設け、かつ、各ダイスを前記ダイス間の間隙ま
わりに回転自在に設けたロータリースウェージング装置
を用い、このロータリースウェージング装置の間隙に沿
って前記複合体を通過させて前記ダイスを複合体に打ち
付けて複合体を鍛造して縮径加工し、その後に焼結して
理論密度が90％以上の圧密度の焼結体を得るものである
から、得られた 超電導線は、その全長に亘って良好な
結晶構造を示すとともに均一な超電導特性を呈し、よっ
て高い臨界電流密度を示すとともに優れた機械強度を示
すものとなる。そして、これにより前記超電導線は、例
えば超電導マグネット用の巻線とした場合でもクラック
を生じることなく巻回することができるなど、線材とし
て優れた特性を示すものとなり、よって各種電導機器に
適用可能なものとなる。[Effects of the Invention] As described above, the method for manufacturing an oxide-based superconducting wire of the present invention provides a method of compacting at least one of an oxide-based superconducting powder and a precursor powder of an oxide superconducting powder to obtain a theoretical density. 60
% Of the green compact, and then sintering the green compact to obtain an intermediate sintered body having a theoretical density of 70% or more, and then compacting the intermediate sintered body At this time, the intermediate sintered body is filled in a metal sheath to form a composite, and multiple dies are brought closer to each other in the direction of expanding or reducing the gap between the dies by facing the processing surfaces of the dies. Alternatively, using a rotary swaging device provided so as to be freely separated and rotatably provided around each gap between the dies, passing the composite along the gap of the rotary swaging device to pass the dies Since the composite is forged, forged and reduced in diameter, and then sintered to obtain a sintered body with a theoretical density of 90% or more, the obtained superconducting wire is If it shows a good crystal structure over the entire length, Exhibit uniform superconductivity in, thus it becomes exhibits excellent mechanical strength with showing high critical current density. Thus, the superconducting wire exhibits excellent characteristics as a wire, such as being able to be wound without generating cracks even when used as a winding for a superconducting magnet, and thus can be applied to various conductive devices. It becomes something.
第１図はこの発明の一例を示す図であって、縮径加工状
態を説明するための側断面図である。 １……中間焼結体、２……管体、３……複合体、４……
ダイス、５……線材、Ａ……ロータリースウェージング
装置。FIG. 1 is a view showing an example of the present invention, and is a side sectional view for explaining a state of diameter reduction processing. 1 ... intermediate sintered body, 2 ... tube, 3 ... composite, 4 ...
Dies, 5: Wire, A: Rotary swaging device.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 杉本 優 東京都江東区木場１丁目５番１号 藤倉 電線株式会社内 (72)発明者 中川 三紀夫 東京都江東区木場１丁目５番１号 藤倉 電線株式会社内 (72)発明者 青木 伸哉 東京都江東区木場１丁目５番１号 藤倉 電線株式会社内 (72)発明者 臼井 俊雄 東京都江東区木場１丁目５番１号 藤倉 電線株式会社内 (72)発明者 久米 篤 東京都江東区木場１丁目５番１号 藤倉 電線株式会社内 (72)発明者 後藤 謙次 東京都江東区木場１丁目５番１号 藤倉 電線株式会社内 (72)発明者 山口 太一 東京都江東区木場１丁目５番１号 藤倉 電線株式会社内 (56)参考文献 特開 昭63−279523（ＪＰ，Ａ) 特開 昭63−318023（ＪＰ，Ａ) 特開 昭63−285812（ＪＰ，Ａ) ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yu Sugimoto 1-5-1 Kiba, Koto-ku, Tokyo Inside Fujikura Electric Wire Co., Ltd. (72) Inventor Mikio Nakagawa 1-1-5-1 Kiba, Koto-ku, Tokyo Fujikura Electric Wire Inside (72) Inventor Shinya Aoki 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Electric Wire Co., Ltd. (72) Inventor Toshio Usui Inside 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd. ( 72) Inventor Atsushi Kume 1-5-1 Kiba, Koto-ku, Tokyo Inside Fujikura Electric Wire Co., Ltd. (72) Inventor Kenji Goto 1-5-1, Kiba 1-chome, Koto-ku, Tokyo Inside Fujikura Electric Wire Co., Ltd. (72) Inventor Taichi Yamaguchi 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd. (56) References JP-A-63-279523 (JP, A) JP-A-63-318023 (JP, ) Patent Akira 63-285812 (JP, A)
Claims (1)
前駆体粉末の少なくとも一方を圧粉成形して理論密度が
60％以上の圧密度の圧粉成形体を得、次いでこの圧粉成
形体を焼結して理論密度が70％以上の圧密度の中間焼結
体を得、その後この中間焼結体を圧密する際に、この中
間焼結体を金属シース内に充填して複合体を形成し、次
いで複数のダイスをダイスの加工面どうしを対向させて
それらのダイス間の間隙を拡げるか縮小する方向に相互
に接近または離間自在に設け、かつ、各ダイスを前記ダ
イス間の間隙まわりに回転自在に設けたロータリースウ
ェージング装置を用い、このロータリースウェージング
装置の間隙に沿って前記複合体を通過させて前記ダイス
を複合体に打ち付けて複合体を鍛造して縮径加工し、そ
の後に焼結して理論密度が90％以上の圧密度の焼結体を
得ることを特徴とする酸化物系超電導線の製造方法。1. A method of compacting at least one of an oxide-based superconducting powder and a precursor powder of an oxide-based superconductor to obtain a theoretical density.
Obtain a green compact with a compact density of 60% or more, and then sinter this compact to obtain an intermediate sintered body with a theoretical density of 70% or more, and then compact this intermediate sintered body. In doing this, the intermediate sintered body is filled into a metal sheath to form a composite, and then a plurality of dies are arranged in such a manner that the processing surfaces of the dies face each other to expand or reduce the gap between the dies. Using a rotary swaging device provided so as to be able to approach or separate from each other, and each die rotatably around the gap between the dies, passing the composite along the gap of the rotary swaging device The oxide-based superconducting wire characterized in that the composite is forged into a composite by forging the die and the diameter of the composite is reduced, and then sintered to obtain a sintered body having a theoretical density of 90% or more. Manufacturing method.
Priority Applications (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62280450A JP2642644B2 (en) | 1987-11-06 | 1987-11-06 | Method for producing oxide-based superconducting wire |
| EP88309193A EP0310453B2 (en) | 1987-10-02 | 1988-10-03 | Method of producing an oxide superconductor without a sheath and an oxide superconductor produced by the method |
| US07/251,847 US5045527A (en) | 1987-10-02 | 1988-10-03 | Method of producing a superconductive oxide conductor |
| DE19883882871 DE3882871T2 (en) | 1987-10-02 | 1988-10-03 | A method for producing an oxide superconducting conductor and an oxide superconducting conductor produced by this method. |
| EP88309195A EP0311337B1 (en) | 1987-10-02 | 1988-10-03 | Method of producing a superconductive oxide conductor and a superconductive oxide conductor produced by the method |
| CN88107874A CN1035220C (en) | 1987-10-02 | 1988-10-03 | Method of producing a superconductive oxide conductor and a superconductive oxide conductor produced by the method |
| CA000579101A CA1313031C (en) | 1987-10-02 | 1988-10-03 | Method of producing a superconductive oxide conductor and an oxide superconductor produced by the method |
| CA000579107A CA1313032C (en) | 1987-10-02 | 1988-10-03 | Method of producing an oxide superconductor without sheath and an oxide superconductor produced by the method |
| DE3880947T DE3880947T3 (en) | 1987-10-02 | 1988-10-03 | Process for the preparation of an oxide superconductor without sheathing and an oxide superconductor produced by this process. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62280450A JP2642644B2 (en) | 1987-11-06 | 1987-11-06 | Method for producing oxide-based superconducting wire |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01122518A JPH01122518A (en) | 1989-05-15 |
| JP2642644B2 true JP2642644B2 (en) | 1997-08-20 |
Family
ID=17625228
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62280450A Expired - Fee Related JP2642644B2 (en) | 1987-10-02 | 1987-11-06 | Method for producing oxide-based superconducting wire |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2642644B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100416713C (en) * | 2003-08-28 | 2008-09-03 | 住友电气工业株式会社 | Method for producing oxide superconducting wire material, method for modifying oxide superconducting wire material, and oxide superconducting wire material |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63285812A (en) * | 1987-05-19 | 1988-11-22 | Toshiba Corp | Manufacture of oxide superconductive wire material |
-
1987
- 1987-11-06 JP JP62280450A patent/JP2642644B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01122518A (en) | 1989-05-15 |
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