JPH0355523B2 - - Google Patents
Info
- Publication number
- JPH0355523B2 JPH0355523B2 JP8371584A JP8371584A JPH0355523B2 JP H0355523 B2 JPH0355523 B2 JP H0355523B2 JP 8371584 A JP8371584 A JP 8371584A JP 8371584 A JP8371584 A JP 8371584A JP H0355523 B2 JPH0355523 B2 JP H0355523B2
- Authority
- JP
- Japan
- Prior art keywords
- arc
- ultrafine particles
- generated
- base material
- electrode
- 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
Links
- 239000011882 ultra-fine particle Substances 0.000 claims description 24
- 239000000463 material Substances 0.000 claims description 13
- 239000002994 raw material Substances 0.000 claims description 13
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 239000007789 gas Substances 0.000 description 16
- 229910052751 metal Inorganic materials 0.000 description 15
- 239000002184 metal Substances 0.000 description 15
- 238000000034 method Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 239000002923 metal particle Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
Landscapes
- Manufacture Of Metal Powder And Suspensions Thereof (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は超微粒子の製造方法に係り、特にアー
クを利用して超微粒子を効率よく製造する方法に
関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing ultrafine particles, and particularly to a method for efficiently producing ultrafine particles using an arc.
従来アークにより超微粒子を製造するには、例
えば特公昭57−44725号公報に記載のように、水
素を含有するガスを用い、このガスが溶融金属中
に溶解、対流、放出する機構を利用している。ま
た特開昭58−130205号公報に記載のように、金属
超微粒子が放電用電極に付着するのを防止すべく
アーク柱を磁石で傾斜させ或いは電極自体を傾斜
させる提案があつた。
Conventionally, in order to produce ultrafine particles using an arc, as described in Japanese Patent Publication No. 57-44725, a hydrogen-containing gas is used, and a mechanism in which this gas is dissolved in molten metal, convected, and released is utilized. ing. Furthermore, as described in Japanese Patent Application Laid-Open No. 130205/1983, there has been a proposal to tilt the arc column with a magnet or to tilt the electrode itself in order to prevent ultrafine metal particles from adhering to the discharge electrode.
上気従来の技術の内、前者は、製造効率につい
ての配慮を欠いていた。また後者は電極への生成
物付着を抑制するに止まり、これとても生成効率
の大幅向上は図れなかつた。
Among the conventional techniques, the former lacks consideration for manufacturing efficiency. Moreover, the latter only suppressed the adhesion of the product to the electrode, and it was not possible to significantly improve the production efficiency.
本発明は上気に鑑みてなしたもので、超微粒子
を効率よく製造することができる方法を提供する
ことを目的とする。 The present invention was made in consideration of the environment, and an object of the present invention is to provide a method that can efficiently produce ultrafine particles.
本発明は上記目的を達成すべく次の手段を講じ
るものである。即ち、棒状の電極先端部１と該電
極とは反対極の超微粒子原料となる母材３との間
にアーク７を発生させて超微粒子を製造するに際
し、該アーク７の断面形状が前記電極先端部１と
前記母材３表面との最短距離を底辺とし、かつ該
底辺に対する頂点７′が前記母材表面よりも上方
に突出する略三角形となるように該母材の蒸気炎
をプラズマ気流で搬送させることを特徴とする。
The present invention takes the following means to achieve the above object. That is, when producing ultrafine particles by generating an arc 7 between the rod-shaped electrode tip 1 and the base material 3, which is the raw material for ultrafine particles and is opposite to the electrode, the cross-sectional shape of the arc 7 is similar to that of the electrode. The steam flame of the base material is passed through the plasma air stream so that the shortest distance between the tip 1 and the surface of the base material 3 forms a substantially triangular shape with the base being the shortest distance and the apex 7' relative to the base protruding above the surface of the base material. It is characterized by being transported by.
上記本発明は新規な現象の発見に基づくもので
ある。すなわち、超微粒子となる原材料表面でア
ークにより母材蒸気を発生させ、さらにそこにプ
ラズマ気流を発生させるアーク電流条件で電磁力
Ｆによりアークを断面略三角形に維持すると、プ
ラズマ気流により発生した超微粒子Ｐを三角形の
頂点７′に向けてアーク流（蒸気炎）が引き込む
ので効率よく搬送できるという現象及び、この搬
送に電磁力を積極的に利用することにより多量の
超微粒子を効率よく製造することができるという
現象に基づくものである。
The present invention described above is based on the discovery of a novel phenomenon. In other words, if the arc is maintained in a substantially triangular cross-section by electromagnetic force F under arc current conditions in which base material vapor is generated by an arc on the surface of the raw material that will become ultrafine particles, and then a plasma airflow is generated there, the ultrafine particles generated by the plasma airflow A phenomenon in which P is drawn in by an arc flow (steam flame) toward the apex 7' of the triangle, allowing it to be transported efficiently, and a large amount of ultrafine particles can be efficiently produced by actively utilizing electromagnetic force for this transport. This is based on the phenomenon that .
以下本発明の実施例について説明する。 Examples of the present invention will be described below.
アークを利用して金属超微粒子を製造するにあ
たり、第１図ａ，ｂに示すように、電極１と保持
台２上にある原材料３の間にAr＋50％H2ガス４
を流してアークを発生させると、電極１がマイナ
スの場合、小電流ではｂ図、大電流域ではａ図に
示すアーク形態をとり、この時の超微粒子の生成
量は第２図に示すようにアーク形態の変化域で大
きく変化する。すなわち、アーク形態がａ図から
ｂ図に変化すると超微粒子の生成量は曲線ｉから
曲線に顕著に向上する。従つてアーク形態の変
化域に近い図ｂの条件で超微粒子を生成する。こ
の時の現象は原材料の表面に陽極点が発生する
と、高温のために金属蒸気が発生し、かつその電
離電圧が低いので電流がこの点に集中的に流入
し、金属蒸気の発生が助長される。さらに電極１
の陰極部及び原材料３の陽極点部では電流密度が
高いので、この部分の圧力が上昇し、電極間の中
央部のアーク圧力より高くなるので、両極部より
中央部に向つてガス気流が発生する。このガス気
流が発生すると両極点でのガスを補うためにまわ
りから矢示５のようにプラズマ気流が発生する。
従つて陽極部に発生した金属蒸気はこのプラズマ
気流（陽極炎）によつて搬送され、連続的に生成
される。 When producing ultrafine metal particles using an arc, as shown in Figure 1 a and b, Ar + 50% H 2 gas 4 is placed between the electrode 1 and the raw material 3 on the holding table 2.
When an arc is generated by flowing a It changes greatly in the changing region of the arc form. That is, when the arc form changes from figure a to figure b, the amount of ultrafine particles produced increases markedly from curve i to curve i. Therefore, ultrafine particles are generated under the conditions shown in Figure b, which are close to the arc form change region. The phenomenon at this time is that when an anode point is generated on the surface of the raw material, metal vapor is generated due to the high temperature, and since the ionization voltage is low, current flows intensively to this point, promoting the generation of metal vapor. Ru. Furthermore, electrode 1
Since the current density is high at the cathode part and the anode point part of raw material 3, the pressure in these parts increases and becomes higher than the arc pressure in the center between the electrodes, so a gas flow is generated from the both poles towards the center. do. When this gas stream is generated, a plasma stream is generated from the surrounding area as shown by arrow 5 to supplement the gas at both poles.
Therefore, the metal vapor generated at the anode portion is transported by this plasma stream (anodic flame) and is continuously generated.
なお電流が増大すると陽極点の面積が増大し、
電流密度が減少するので陽極炎は減少する。反面
陰極部の電流密度が増大するため、陰極炎は増大
し、ａ図に示すアーク形態となり、金属蒸気の生
成量が少なくなる。 Note that as the current increases, the area of the anode point increases,
The anodic flame is reduced because the current density is reduced. On the other hand, since the current density in the cathode section increases, the cathode flame increases, resulting in the arc form shown in Figure a, and the amount of metal vapor produced decreases.
アークを発生する際の雰囲気ガスはアークが容
易に発生しやすAr、Heガス等の不活性ガスに熱
ピンチ力の大きいH2ガス、水蒸気、He、SF6、
フレオン、O2、N2、CH4、CO2ガス等を混合し
たガスを用いたり、電源より十分な電位を得て、
熱ピンチ力の大きいH2ガス、水蒸気、He、SF6、
フレオン、O2、N2、CO2ガス等を用いると能率
良く超微粒子を生成することができる。 Atmospheric gases used to generate an arc include inert gases such as Ar and He gas, which easily generate an arc, H2 gas, water vapor, He, SF6 , and other gases that have a large thermal pinching force.
Using a gas mixture of freon, O 2 , N 2 , CH 4 , CO 2 gas, etc., or obtaining a sufficient potential from a power supply,
H2 gas, water vapor, He, SF6 , which have a large thermal pinch force,
Ultrafine particles can be efficiently generated using freon, O 2 , N 2 , CO 2 gas, or the like.
対となる電極の原材料３は金属蒸気を積極的に
発生させるには小さな形状にして温度上昇により
金属蒸気の発生を助長させたり、第３図に示すよ
うにワイヤ形状にすると同理由により良い。ワイ
ヤ形状にした場合は消耗量が大きいので、連続供
給する機構及びアーク長を一定に制御する機構を
設ける。 In order to actively generate metal vapor, the raw material 3 of the pair of electrodes may be formed into a small shape to promote the generation of metal vapor by increasing the temperature, or may be formed into a wire shape as shown in FIG. 3 for the same reason. If it is made into a wire shape, the amount of consumption is large, so a mechanism for continuous supply and a mechanism for controlling the arc length to be constant are provided.
次に電極の配置を第３図乃至第５図のようにθ
＝０〜170°特に望ましくは40〜45°の角度を与え
ることによつて、アーク電流の増大によるアーク
形態の変化域が生じにくくなる。これは通電電流
による電磁力が電極間のアークを偏向（矢印６）
させ、また陽極炎及び陰極炎が作られるアーク断
面形状を符号７に示すように略三角形となるよう
に発生させ、金属蒸気流をこの炎で搬送する。ア
ーク形状は電極先端部１と原材料（母材）３の表
面とを結ぶ最短距離を底辺として、頂点７が中空
へ突出するような断面略三角形を呈し、第３図乃
至第５図いずれの実施例もこの条件に従う。従つ
て先の第１図より大きい電流を流しても、両極の
プラズマ気流が対向していないので、通電流の増
加に従つて金属蒸気の発生量は増大し、プラズマ
気流で搬送されながら生成される。 Next, arrange the electrodes at θ as shown in Figures 3 to 5.
By providing an angle of 0 to 170 degrees, preferably 40 to 45 degrees, changes in arc form due to increase in arc current are less likely to occur. This is because the electromagnetic force caused by the flowing current deflects the arc between the electrodes (arrow 6).
Further, the cross-sectional shape of the arc where an anodic flame and a cathodic flame are formed is approximately triangular as shown by reference numeral 7, and a metal vapor flow is conveyed by this flame. The arc shape has a substantially triangular cross section with the shortest distance connecting the electrode tip 1 and the surface of the raw material (base material) 3 as the base, and the apex 7 protrudes into the air. The example also follows this condition. Therefore, even if a larger current is applied than in Figure 1 above, the plasma airflows at both poles do not face each other, so the amount of metal vapor generated increases as the applied current increases, and metal vapor is generated while being carried by the plasma airflow. Ru.
更に第５図に示すように原材料の保持台２の通
電経路を電極１と平行になるようにすると、通電
電流による電磁力がアークを外側（矢印６）に偏
向させ、陽極炎及び陰極炎をアーク７のように生
じさせる。このため金属蒸気はこの気流に搬送さ
れて生成する。その結果、先の第３図、第４図で
説明した理由により、電流の増大による超微粒子
の生成量増大が可能となる。 Furthermore, as shown in Fig. 5, if the current-carrying path of the raw material holding table 2 is made parallel to the electrode 1, the electromagnetic force caused by the current will deflect the arc outward (arrow 6), causing an anodic flame and a cathodic flame. Create it like arc 7. Therefore, metal vapor is carried by this air flow and generated. As a result, for the reason explained in FIGS. 3 and 4 above, it becomes possible to increase the amount of ultrafine particles produced by increasing the current.
より生成量の増大を計るには第６図に示すよう
に、電極を複数配置し、電極の一方は共通電位に
し、さらに先の第５図に示したように両極炎がア
ーク７のように生じさせるように通電経路を設け
ることにより、電極数に比例した生成量の増大が
計れる。 In order to further increase the production amount, as shown in Figure 6, multiple electrodes are arranged, one of the electrodes is at a common potential, and as shown in Figure 5 above, the bipolar flame is arranged like arc 7. By providing an energizing path so as to cause the generation, the amount of generation can be increased in proportion to the number of electrodes.
電極材料の一方にＷ、Taのように溶融温度の
高いものを用いて超微粒子を生成するのが一般的
であるが、同種材料を両電極に用いるとより純度
の高い超微粒子を得ることもできる。また２種以
上の金属が混合または合金化した超微粒子を得る
には合金原材料の電極を対にし、両電極の材質を
変えることで可能である。蒸発量は極性により変
化するが、直流の場合に前述の極性と逆の極性、
または交流の電流を用いて生成することもでき
る。なお交流の電流を用いる場合は、電極材質及
び雰囲気ガスによつて異なるが、交流電流の周波
数、供給電圧または再点弧時の高電圧印加等の条
件を適正に選定することにより、効率よく超微粒
子を得ることができる。 It is common to generate ultrafine particles by using a material with a high melting temperature, such as W or Ta, for one electrode material, but it is also possible to obtain ultrafine particles with higher purity by using the same material for both electrodes. can. Furthermore, ultrafine particles in which two or more metals are mixed or alloyed can be obtained by pairing electrodes of alloy raw materials and changing the materials of both electrodes. The amount of evaporation changes depending on the polarity, but in the case of direct current, the polarity opposite to the above polarity,
Alternatively, it can also be generated using alternating current. Note that when using alternating current, it depends on the electrode material and atmospheric gas, but by appropriately selecting conditions such as the frequency of the alternating current, the supply voltage, and the application of high voltage at the time of restriking, it is possible to efficiently Fine particles can be obtained.
超微粒子の大きさは、第１図の方法で製造する
場合、金属蒸気がアークにより再加熱され、大き
く生長するため、いく分粒径のバラツキが出る
が、第３図〜第６図の方法では金属蒸気が再加熱
される時間が短かくなり、粒径のバラツキは少な
くなる。 When producing ultrafine particles using the method shown in Figure 1, the metal vapor is reheated by an arc and grows, resulting in some variation in particle size. In this case, the time for reheating the metal vapor is shortened, and the variation in particle size is reduced.
以上説明したように、本発明によれば電極の一
方または両方を超微粒子の製造原料として対向配
置し、プラズマ気流を両極より発生させたり、ア
ーク電流による電磁力又はアーク近傍に設けた金
属、磁石が両極間のアークを偏向させるようにす
ることにより、従来の水素アーク加熱法に比較し
て効率のよい超微粒子の製造方法が得られる。
As explained above, according to the present invention, one or both of the electrodes are arranged facing each other as raw materials for producing ultrafine particles, and a plasma airflow is generated from both poles, and the electromagnetic force generated by the arc current or the metal or magnet provided near the arc By deflecting the arc between the two poles, a method for producing ultrafine particles can be obtained that is more efficient than the conventional hydrogen arc heating method.
第１図ａ，ｂはアーク発生形態の説明図で、ａ
図は従来の製造方法におけるアーク形態、ｂ図は
本発明の製造方法におけるアーク形態を示す図、
第２図はアーク形態による超微粒子の生成量を示
す特性図で曲線ｉが従来方法による生成量、曲線
が本発明の製造方法による生成量、第３図から
第６図まではいずれも本発明による超微粒子の製
造方法の実施例装置の模式図を示す。
１……電極、２……原材料保持台、３……原材
料（対となる電極）、４……雰囲気ガス、５……
プラズマ気流、６……アークに作用する力の方
向、７……アーク（陰極炎・陽極炎）、７′……頂
点。
Figures 1a and 1b are explanatory diagrams of the form of arc generation, and a
The figure shows the arc form in the conventional manufacturing method, and the figure b shows the arc form in the manufacturing method of the present invention.
FIG. 2 is a characteristic diagram showing the amount of ultrafine particles produced depending on the arc form, where curve i is the amount produced by the conventional method, the curve is the amount produced by the manufacturing method of the present invention, and FIGS. 3 to 6 are the amounts produced by the present invention. 1 shows a schematic diagram of an example apparatus of a method for producing ultrafine particles according to the method of the present invention. 1... Electrode, 2... Raw material holding stand, 3... Raw material (pair electrode), 4... Atmospheric gas, 5...
Plasma airflow, 6... Direction of force acting on the arc, 7... Arc (cathode flame/anodic flame), 7'... Vertex.
Claims (1)
微粒子原料となる母材３との間にアーク７を発生
させて超微粒子を製造するに際し、該アーク７の
断面形状が前記電極先端部１と前記母材３表面と
の最短距離を底辺とし、かつ該底辺に対する頂点
７′が前記母材表面よりも上方へ突出する略三角
形となるように該母材の蒸気炎をプラズマ気流で
搬送させることを特徴とする超微粒子の製造方
法。1 When producing ultrafine particles by generating an arc 7 between a rod-shaped electrode tip 1 and a base material 3 that is an ultrafine particle raw material opposite to the electrode, the cross-sectional shape of the arc 7 is the same as the electrode tip. The steam flame of the base material is heated with a plasma air flow so that the shortest distance between the part 1 and the surface of the base material 3 forms a substantially triangular shape with the base being the shortest distance and the apex 7' relative to the base protruding above the surface of the base material. A method for producing ultrafine particles, characterized by transporting them.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8371584A JPS60228609A (en) | 1984-04-27 | 1984-04-27 | Method for producing ultrafine particles |
| US06/726,651 US4610718A (en) | 1984-04-27 | 1985-04-24 | Method for manufacturing ultra-fine particles |
| EP85105063A EP0161563B1 (en) | 1984-04-27 | 1985-04-25 | Method of and apparatus for manufacturing ultra-fine particles |
| DE8585105063T DE3576782D1 (en) | 1984-04-27 | 1985-04-25 | METHOD AND DEVICE FOR PRODUCING ULTRAFINE PARTICLES. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8371584A JPS60228609A (en) | 1984-04-27 | 1984-04-27 | Method for producing ultrafine particles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60228609A JPS60228609A (en) | 1985-11-13 |
| JPH0355523B2 true JPH0355523B2 (en) | 1991-08-23 |
Family
ID=13810198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8371584A Granted JPS60228609A (en) | 1984-04-27 | 1984-04-27 | Method for producing ultrafine particles |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60228609A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62207802A (en) * | 1986-03-10 | 1987-09-12 | Hitachi Ltd | Apparatus for forming ultrafine particle |
| JP5940441B2 (en) * | 2012-02-16 | 2016-06-29 | 東芝三菱電機産業システム株式会社 | Fine particle generation apparatus and fine particle generation method |
-
1984
- 1984-04-27 JP JP8371584A patent/JPS60228609A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60228609A (en) | 1985-11-13 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |