JP2008240059A - Method for producing metal powder - Google Patents

Method for producing metal powder Download PDF

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JP2008240059A
JP2008240059A JP2007081520A JP2007081520A JP2008240059A JP 2008240059 A JP2008240059 A JP 2008240059A JP 2007081520 A JP2007081520 A JP 2007081520A JP 2007081520 A JP2007081520 A JP 2007081520A JP 2008240059 A JP2008240059 A JP 2008240059A
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disk
metal powder
powder
rotational speed
coarse powder
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Takayuki Araki
隆之 荒木
Makoto Horiguchi
誠 堀口
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Mitsui Mining and Smelting Co Ltd
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Mitsui Mining and Smelting Co Ltd
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<P>PROBLEM TO BE SOLVED: To provide a method for producing metal powder, in which the metal powder having desired grain size distribution and average grain diameter can be stably obtained. <P>SOLUTION: In the method for producing metal powder where a molten metal is continuously fed to the surface of a disk rotating at a high speed, and is atomized by centrifugal force, so as to be powdered, in the process where the disk is rotated at a prescribed speed of revolution for obtaining metal powder with the desired average grain diameter, so as to continuously produce the metal powder, on the condition that the speed of revolution of the disk is within the range of ±10% of the prescribed speed of revolution, control is performed either the speed of revolution of the disk is lowered in accordance with the lowering of the rate of coarse powder in the obtained metal powder or the speed of revolution of the disk is raised in accordance with the raise of the rate of the coarse powder in the obtained metal powder. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、金属粉の製造方法に関し、より詳しくは、粒度分布や平均粒径が安定した金属粉を継続的に製造できる製造方法に関する。   The present invention relates to a method for producing metal powder, and more particularly to a production method capable of continuously producing metal powder having a stable particle size distribution and average particle size.

電子部品の接合等に使用されているはんだ粉などの金属粉の代表的な製造方法として、金属溶融物(以下「熔湯」という)を細孔から流出させこれに窒素ガス等を作用させて飛散させ粉末化するガス噴霧法や、高速度で回転するディスク上に熔湯を供給し遠心力により噴霧させて粉末化する遠心噴霧法などが挙げられる。前者のガス噴霧法は粒度分布が広くなりがちであり、後者の遠心噴霧法のほうが粒度分布は狭くなるため、遠心噴霧法が金属粉の製造には適している(特許文献1参照)。この遠心噴霧法では、所望の平均粒径の金属粉を製造するために、通常、毎分当たりのディスクの回転数(以下、単に「回転数」と称する)や材質等の製造条件を所定のものに固定して製造される。しかしながら、所望の平均粒径の金属粉を得るためにディスク回転数等の製造条件を所定のものにしても、所望の粒度分布を有する金属粉を安定した状態で継続的に得ることが困難であった。   As a typical manufacturing method of metal powder such as solder powder used for joining electronic parts, etc., a metal melt (hereinafter referred to as “molten metal”) flows out from the pores and nitrogen gas or the like is allowed to act on it. Examples thereof include a gas spraying method in which powder is dispersed and powdered, and a centrifugal spraying method in which molten metal is supplied onto a disk rotating at a high speed and sprayed by centrifugal force to be powdered. The former gas spraying method tends to have a wide particle size distribution, and the latter centrifugal spraying method has a narrower particle size distribution, so the centrifugal spraying method is suitable for the production of metal powder (see Patent Document 1). In this centrifugal spraying method, in order to produce a metal powder having a desired average particle diameter, the production conditions such as the number of revolutions of the disk per minute (hereinafter simply referred to as “the number of revolutions”) and the material are usually determined. Manufactured by fixing to things. However, it is difficult to continuously obtain a metal powder having a desired particle size distribution in a stable state even if the manufacturing conditions such as the rotational speed of the disk are set to a predetermined value in order to obtain a metal powder having a desired average particle diameter. there were.

特開平6−340905号公報(段落番号[0002]、[0003]等)JP-A-6-340905 (paragraph numbers [0002], [0003], etc.)

本発明は上述した事情に鑑み、所望の粒度分布を有し、特に粗粉の少ない金属粉を安定して得ることができる金属粉の製造方法を提供することを目的とする。   An object of this invention is to provide the manufacturing method of the metal powder which has the desired particle size distribution and can obtain the metal powder with few coarse powders stably in view of the situation mentioned above.

本発明者らは上記目的を達成するために鋭意検討した結果、遠心噴霧法において、得られる金属粉の粗粉率の変化に応じて製造途中でディスクの回転数を制御することにより上記目的が達成されることを見いだし、本発明を完成した。   As a result of intensive studies to achieve the above object, the present inventors have found that the above object is achieved by controlling the number of revolutions of the disk during the production according to the change in the coarse powder rate of the obtained metal powder in the centrifugal spray method. It has been found that this has been achieved, and the present invention has been completed.

即ち、本発明の金属粉の製造方法は、高速度で回転するディスク上に熔湯を連続的に供給し遠心力により噴霧させて粉末化する金属粉の製造方法において、前記ディスクを所望の平均粒径の金属粉を得るための所定の回転数で回転させて連続的に金属粉を製造する途中で、前記ディスクの回転数を前記所定の回転数に対して±10%以内の範囲内を条件として、得られる金属粉の粗粉率の下降に応じてディスクの回転数を下降させるか、得られる金属粉の粗粉率の上昇に応じてディスクの回転数を上昇させるかする制御をすることを特徴とする。   That is, the metal powder production method of the present invention is a metal powder production method in which molten metal is continuously supplied onto a disk rotating at a high speed and sprayed by centrifugal force to form powder. In the course of continuously producing metal powder by rotating at a predetermined rotational speed to obtain a metal powder having a particle diameter, the rotational speed of the disk is within ± 10% of the predetermined rotational speed. As a condition, control is performed to lower the rotational speed of the disk according to the decrease in the coarse powder rate of the obtained metal powder, or to increase the rotational speed of the disk according to the increase of the coarse powder ratio of the obtained metal powder. It is characterized by that.

また、本発明の金属粉の製造方法は、前記ディスクの回転数の制御において、噴霧開始時のディスクの回転数を前記所定の回転数よりも速い回転数とし、得られる金属粉の粗粉率の下降に応じて前記ディスクの回転数を前記噴霧開始時のディスクの回転数よりも下降させて、その後、得られる金属粉の粗粉率の上昇に応じて前記ディスクの回転数を上昇させるのが好ましい。   Further, in the method for producing metal powder of the present invention, in controlling the number of revolutions of the disk, the number of revolutions of the disk at the start of spraying is set to a number of revolutions faster than the predetermined number of revolutions, and the coarse powder rate of the obtained metal powder The rotational speed of the disk is lowered below the rotational speed of the disk at the start of spraying, and then the rotational speed of the disk is increased according to the increase in the coarse powder rate of the obtained metal powder. Is preferred.

また、噴霧開始後、前記粗粉率が所定値未満となったら前記ディスクの回転数を前記噴霧開始時のディスクの回転数よりも下降させて、その後、前記粗粉率が前記所定値を超えたら前記ディスクの回転数を上昇させてもよい。   Further, after the spraying starts, when the coarse powder ratio becomes less than a predetermined value, the rotational speed of the disk is lowered below the rotational speed of the disk at the start of spraying, and then the coarse powder ratio exceeds the predetermined value. Then, the rotational speed of the disk may be increased.

さらに、前記ディスクを前記所定の回転数で回転させた製造条件で予め粗粉率の経時変化を測定しておき、その測定結果に応じて噴霧開始後所定のタイミングで前記ディスクの回転数を制御してもよい。   Further, the change over time in the coarse powder ratio is measured in advance under the manufacturing conditions in which the disk is rotated at the predetermined rotation speed, and the rotation speed of the disk is controlled at a predetermined timing after the start of spraying according to the measurement result. May be.

本発明の金属粉の製造方法によれば、粗粉率が安定化し、粒度分布や平均粒径が安定した金属粉を継続的に製造することができるという効果を奏する。   According to the method for producing metal powder of the present invention, it is possible to continuously produce metal powder having a stable coarse powder rate and a stable particle size distribution and average particle size.

以下、本発明を実施形態に基づいて詳細に説明する。
本発明の金属粉の製造方法は、高速度で回転するディスク上に金属溶融物(熔湯)を供給し遠心力により噴霧させて粉末化して金属粉を得る遠心噴霧法に関するものである。
Hereinafter, the present invention will be described in detail based on embodiments.
The metal powder production method of the present invention relates to a centrifugal spray method in which a metal melt (molten metal) is supplied onto a disk rotating at a high speed and sprayed by centrifugal force to obtain a metal powder.

遠心噴霧法ではディスクの回転数に応じて得られる金属粉の粒径が変化する。特開2002−317212号公報(段落[0009])等に記載されるように、ディスクの回転数が大きいほど得られる金属粉の粒径は小さくなり、ディスクの回転数が小さいほど得られる金属粉の粒径は大きくなる。したがって、通常、所望の金属粉の平均粒径に応じて、ディスクの回転数は所定の数値に設定される。   In the centrifugal spraying method, the particle size of the obtained metal powder changes according to the rotational speed of the disk. As described in Japanese Patent Application Laid-Open No. 2002-317212 (paragraph [0009]) and the like, the larger the number of revolutions of the disk, the smaller the particle size of the obtained metal powder, and the smaller the number of revolutions of the disk, the more obtainable metal powder. The particle size of becomes larger. Therefore, the number of rotations of the disk is usually set to a predetermined value according to the desired average particle diameter of the metal powder.

そして、従来の金属粉の製造においては、ディスクの回転数を一定にすれば所望の平均粒径の金属粉が安定的に得られると考えられていたが、このような製造方法では、経時的に粗粉率が変化し、その結果、安定した金属粉は得られなかった。   In the conventional production of metal powder, it has been considered that a metal powder having a desired average particle diameter can be stably obtained if the number of revolutions of the disk is kept constant. As a result, a stable metal powder was not obtained.

これに対し本発明の金属粉の製造方法は、所望の粒径の金属粉を得るためにディスクを所定の回転数で回転させて連続的に金属粉を製造する途中で、得られる金属粉の粗粉率の変化に応じて、ディスクの回転数を上記所定の回転数に対して±10%以内の範囲内で制御するものである。   On the other hand, in the method for producing metal powder of the present invention, in order to obtain metal powder having a desired particle size, the disk is rotated at a predetermined rotational speed to continuously produce metal powder. According to the change in the coarse powder rate, the rotational speed of the disk is controlled within a range of ± 10% with respect to the predetermined rotational speed.

具体的には、ディスクの回転数を、上記所定の回転数に対して±10%以内の範囲内を条件として、得られる金属粉の粗粉率の下降に応じてディスクの回転数を下降させるか、得られる金属粉の粗粉率の上昇に応じてディスクの回転数を上昇させるかする制御を行う。   Specifically, the number of revolutions of the disk is decreased in accordance with the decrease in the coarse powder rate of the obtained metal powder, on condition that the number of revolutions of the disk is within ± 10% of the predetermined number of revolutions. Alternatively, control is performed to increase the rotational speed of the disk in accordance with the increase in the coarse powder rate of the obtained metal powder.

本明細書において、「ディスクを所望の平均粒径の金属粉を得るための所定の回転数で回転させる」という操作は、前述のとおり、所望の金属粉の平均粒径に応じて、ディスクの回転数を所定の数値に設定し、金属粉を連続的に製造することを指すが、この所定の回転数は、製造する金属粉に応じて定めることができる。例えば、平均粒径10〜70μmのはんだ粉を製造する場合は所定のディスク回転数を20000〜100000rpmの範囲内とし、平均粒径20〜40μmの銅粉を製造する場合は所定のディスク回転数を70000〜100000rpmの範囲内とし、いずれの場合も、熔湯の温度や組成等に応じて調整すればよい。   In the present specification, as described above, the operation of “rotating the disk at a predetermined rotational speed for obtaining metal powder having a desired average particle diameter” is performed according to the average particle diameter of the desired metal powder. Although the rotational speed is set to a predetermined numerical value and the metal powder is continuously manufactured, the predetermined rotational speed can be determined according to the metal powder to be manufactured. For example, when producing solder powder having an average particle diameter of 10 to 70 μm, the predetermined disk rotation speed is set within the range of 20000 to 100000 rpm, and when producing copper powder having an average particle diameter of 20 to 40 μm, the predetermined disk rotation speed is set to It may be within the range of 70000-100,000 rpm, and in any case, it may be adjusted according to the temperature, composition, etc. of the molten metal.

本発明の金属粉の製造方法においては、上記所定の回転数を基準として連続製造するものの、その回転数を特定の条件下で制御することにより、連続製造を続けた際に生じる粗粉率の変化を抑制でき、また、平均粒径よりも小さい微粉の量はほとんど変化しないため、粒度分布や平均粒径が安定した金属粉を継続的に製造することができる。   In the method for producing metal powder of the present invention, although the continuous production is based on the predetermined rotational speed, the coarse powder rate generated when continuous production is continued by controlling the rotational speed under specific conditions. Since the change can be suppressed and the amount of fine powder smaller than the average particle diameter hardly changes, metal powder having a stable particle size distribution and average particle diameter can be continuously produced.

なお、本発明でいう粗粉率とは、粒径が所定値以上の粒子(粗粉)の粒子全体に占める重量割合であり、金属粉がはんだ粉であれば、JIS Z 3284に定められている各サイズレベルにおいて1質量%以下の含有量が認められる限界粒径以上の粒子を粗粉粒子と捉える。具体的にはサイズに応じて適切なふるいを用い、例えばサイズレベル3では63μm以上、サイズレベル4では45μm以上、サイズレベル5では38μm以上のふるい上分を計量し、粒子全体量中の比率を算出すればよい。また、はんだ粉を上記規格外の平均粒径に制御する場合や、はんだ粉以外の金属粉を制御する場合は、平均粒径の1.5倍以上の粒子を粗粉粒子と捉え、上記はんだ粉の事例同様に粗粉率を算出する。   In addition, the coarse powder rate as used in the field of this invention is a weight ratio which occupies the whole particle | grains of a particle | grain (coarse powder) whose particle size is a predetermined value or more, and if metal powder is solder powder, it is prescribed in JIS Z 3284. Particles having a particle size equal to or larger than the limit particle size at which a content of 1% by mass or less is recognized at each size level are regarded as coarse powder particles. Specifically, an appropriate sieve is used according to the size. For example, the size above 3 μm is measured at 63 μm at size level 3, 45 μm at size level 4 and 38 μm at size level 5, and the ratio in the total amount of particles is determined. What is necessary is just to calculate. In addition, when controlling the solder powder to an average particle size other than the above standard, or when controlling a metal powder other than the solder powder, the particles of 1.5 times or more the average particle size are regarded as coarse powder particles, The coarse powder rate is calculated in the same manner as the powder example.

粗粉率と経過時間の関係について、従来一般的に行われていた遠心噴霧法による金属粉の製造方法においては、噴霧初期では熔湯温度に対してディスク温度が低く熔湯に対する濡れ性が悪いため粗粉率が高いが、その後、時間の経過と共にディスク温度が上昇するので、熔湯に対する濡れ性が向上して経時的に粗粉率が下降することを、本発明者らは知見した。   Regarding the relationship between the coarse powder rate and the elapsed time, in the conventional metal powder production method by centrifugal spraying, the disk temperature is low with respect to the melt temperature and the wettability to the melt is poor at the initial stage of spraying. Therefore, although the coarse powder rate is high, the present inventors have found that since the disk temperature rises with time, the wettability to the molten metal is improved and the coarse powder rate decreases with time.

また、このように経時的に粗粉率が下降した後は、粗粉率はしばらくほぼ一定となるが、その後時間の経過と共に粗粉率が上昇していくことも本発明者らは知見した。この現象は、熔湯によるディスクのエロージョンに起因するディスクの摩耗劣化や、ディスク材質と熔湯間で生じる生成物の形成により、熔湯がディスク末端まで行き亘らずにディスクの途中から飛散すること等が原因と推測される。   In addition, after the coarse powder rate has decreased over time in this way, the coarse powder rate becomes almost constant for a while, but the present inventors have also found that the coarse powder rate increases with the passage of time thereafter. . This phenomenon is caused by the deterioration of the disk due to the erosion of the disk due to the molten metal and the formation of a product generated between the disk material and the molten metal, and the molten metal scatters from the middle of the disk without reaching the end of the disk. This is presumed to be the cause.

このように、経時的に粒度分布が変化することを知見したので、本発明においては、得られる金属粉の粗粉率の経時変化に応じてディスク回転数を下降、あるいは上昇させるという制御を行うことにより、粗粉率を制御し、粒度分布や平均粒径を安定化させている。したがって、長時間連続して製造しても、所望の粒度分布や平均粒径を有する金属粉を安定して製造することができる。換言すると、得られる金属粉の粗粉率に応じてディスクの回転数を制御することにより、金属粉の粗粉率を所定の範囲内に調整でき、粒度分布を制御して安定化させることができるため、所望の粒度分布や平均粒径を有する金属粉を安定して得ることができる。   Thus, since it has been found that the particle size distribution changes with time, in the present invention, control is performed to lower or increase the disk rotation speed in accordance with the change with time of the coarse powder rate of the obtained metal powder. Thus, the coarse powder rate is controlled, and the particle size distribution and the average particle size are stabilized. Therefore, even if it manufactures continuously for a long time, the metal powder which has a desired particle size distribution and an average particle diameter can be manufactured stably. In other words, by controlling the number of revolutions of the disk according to the coarse powder rate of the obtained metal powder, the coarse powder rate of the metal powder can be adjusted within a predetermined range, and the particle size distribution can be controlled and stabilized. Therefore, metal powder having a desired particle size distribution and average particle size can be stably obtained.

例えば、噴霧開始時は、所望の平均粒径の金属粉を得るための所定の回転数よりも速い回転数でディスクを回転させ、得られる金属粉の粗粉率の下降に応じてディスクの回転数を噴霧開始時のディスクの回転数よりも下降させることにより、粗粉率の下降を抑制する。   For example, at the start of spraying, the disk is rotated at a rotational speed faster than a predetermined rotational speed for obtaining metal powder having a desired average particle diameter, and the disk is rotated according to the decrease in the coarse powder rate of the obtained metal powder. By decreasing the number below the number of rotations of the disk at the start of spraying, the decrease in the coarse powder rate is suppressed.

その後、ディスクの摩耗劣化等による粗粉率の上昇に応じて、ディスクの回転数を上昇させることにより粗粉率の上昇を抑制する。これにより、継続的に粗粉率を安定化させることができ、所望の粒度分布や平均粒径を有する金属粉を安定して得ることができる。   Thereafter, the increase in the coarse powder rate is suppressed by increasing the number of revolutions of the disc in accordance with the increase in the coarse powder rate due to wear deterioration of the disc. Thereby, a coarse powder rate can be stabilized continuously and the metal powder which has a desired particle size distribution and an average particle diameter can be obtained stably.

なお、上記金属粉の粗粉率の下降に応じてディスクの回転数を噴霧開始時のディスクの回転数よりも下降させる際には、所定の回転数にまで下降させるのが好ましい。したがって、その場合、粗粉率の上昇に応じて、ディスクの回転数は所定の回転数を超えた状態まで上昇させることになる。   When the rotational speed of the disk is lowered below the rotational speed of the disk at the start of spraying in accordance with the decrease in the coarse powder rate of the metal powder, it is preferably lowered to a predetermined rotational speed. Therefore, in that case, the rotational speed of the disk is increased to a state exceeding a predetermined rotational speed as the coarse powder rate increases.

また、ディスクの温度が上昇することにより噴霧初期に粗粉率が上昇することに対しては、ディスクの温度を制御するという手段も考えられるが、本発明の製造方法によれば、ディスクの温度に関わらず、所望の粗粉率にすることができる。   Further, for the increase in the coarse powder rate at the initial stage of spraying due to an increase in the temperature of the disk, a means of controlling the temperature of the disk can be considered, but according to the manufacturing method of the present invention, the temperature of the disk is considered. Regardless, the desired coarse powder rate can be achieved.

また、ディスクの摩耗劣化等により粗粉率が上昇することに対しては、ディスクを摩耗劣化させないようにディスクを硬質で耐摩耗性に優れた材質にするという手段も考えられるが、製造に用いられる熔湯の成分によってはディスクの濡れ不良が生じ、得られる金属粉の粒径が粗くなり、粗粉率が低い金属粉を得ることができないという問題が生じる。これに対し、本発明の金属粉の製造方法によれば、このような問題は生じない。   In addition, for the increase in coarse powder rate due to disc wear deterioration, etc., a means of making the disc hard and excellent in wear resistance so as not to cause wear degradation of the disc can be considered, but it is used for manufacturing. Depending on the composition of the molten metal, poor wetting of the disk occurs, the particle size of the obtained metal powder becomes coarse, and there is a problem that metal powder with a low coarse powder rate cannot be obtained. On the other hand, according to the manufacturing method of the metal powder of this invention, such a problem does not arise.

以上述べたように、本発明の金属粉の製造方法によれば、粗粉率の経時変化に応じて製造途中でディスクの回転数を制御することにより、粗粉率を安定化し、粒度分布や平均粒径が安定した金属粉を継続的に製造することができる。   As described above, according to the method for producing metal powder of the present invention, the coarse powder rate is stabilized by controlling the number of revolutions of the disk during the production according to the change in coarse powder rate with time, and the particle size distribution and A metal powder having a stable average particle diameter can be continuously produced.

また、粗粉率が安定するので、長時間連続して金属粉を製造しても、1バッチ当たりの所望の金属粉製造歩留まりが高く、粗粉率が変動する従来の製造方法に比べて、格段に製造効率が優れている。   In addition, since the coarse powder rate is stable, even if metal powder is produced continuously for a long time, the desired metal powder production yield per batch is high, compared to the conventional production method in which the coarse powder rate fluctuates, Production efficiency is remarkably excellent.

ところで、ディスクの回転数を上昇又は下降させる時期や回転数の上昇又は下降割合は、金属粉の粗粉率に応じて適宜決定される。したがって、所望の平均粒径の金属粉を得るための所定のディスク回転数で試験操業を行い、得られる金属粉の粗粉率の経時変化を予め測定しておくことにより、回転数を上昇又は下降する時期や、回転数の上昇又は下降の割合を決定してもよい。   By the way, the timing for increasing or decreasing the rotational speed of the disk and the increasing or decreasing rate of the rotational speed are appropriately determined according to the coarse powder ratio of the metal powder. Therefore, by performing a test operation at a predetermined disk rotation speed for obtaining metal powder having a desired average particle diameter, the rotation speed is increased or increased by measuring the change over time in the coarse powder ratio of the obtained metal powder. You may determine the time to descend | decrease and the ratio of the raise or fall of rotation speed.

なお、回転数の上昇又は下降の割合は、所望の平均粒径の金属粉を得るための所定の回転数に対して±10%以内の範囲内とする。この範囲であれば、得られる金属粉の個々の粒径が所望の平均粒径からかけ離れないようにすることができる。この回転数の上昇又は下降の割合は、さらに好ましくは所定の回転数に対して±3〜8%程度であり、この範囲で行えば、より効果的に粗粉率や粒度分布を調整できる。   The rate of increase or decrease in the rotational speed is within a range of ± 10% with respect to a predetermined rotational speed for obtaining metal powder having a desired average particle diameter. If it is this range, it can prevent that the individual particle size of the metal powder obtained does not deviate from a desired average particle size. The rate of increase or decrease in the rotational speed is more preferably about ± 3 to 8% with respect to the predetermined rotational speed, and the coarse powder rate and the particle size distribution can be adjusted more effectively if performed within this range.

ディスクの回転数を上昇又は下降させる工程は一度でも複数回でもよいが、上述したように、噴霧初期は粗粉率が下降し、その後粗粉率が上昇するため、ディスクの回転数を下降させた後にディスクの回転数を上昇させることが好ましい。また、ディスクの回転数は段階的に上昇又は下降させても、漸次上昇又は下降させてもよい。勿論、粗粉率の経時変化を予め測定しておくのではなく、得られる金属粉の粗粉率を所定のタイミングで測定し、その測定結果に応じて、例えば、噴霧開始後粗粉率が所定値未満となったら、ディスクの回転数を噴霧開始時のディスクの回転数よりも下降させて上記所定の回転数とし、その後、粗粉率が所定値を超えたらディスクの回転数を前記所定の回転数よりも上昇させるようにしてもよい。この回転数を下降又は上昇させる基準となる粗粉率の所定値は、目的とする粗粉率から適宜設定できる。   The process of increasing or decreasing the rotational speed of the disk may be performed once or multiple times. However, as described above, the coarse powder ratio decreases at the initial stage of spraying, and then the coarse powder ratio increases. Therefore, the rotational speed of the disk is decreased. After that, it is preferable to increase the rotational speed of the disk. Further, the rotational speed of the disk may be increased or decreased stepwise, or may be gradually increased or decreased. Of course, rather than measuring the change over time of the coarse powder rate in advance, the coarse powder rate of the obtained metal powder is measured at a predetermined timing, and depending on the measurement result, for example, the coarse powder rate after the start of spraying is If it becomes less than the predetermined value, the rotational speed of the disk is lowered below the rotational speed of the disk at the start of spraying to the above-mentioned predetermined rotational speed, and then the rotational speed of the disk is set to the predetermined speed when the coarse powder ratio exceeds the predetermined value. You may make it raise from the rotation speed of. The predetermined value of the coarse powder rate that serves as a reference for decreasing or increasing the rotational speed can be appropriately set from the target coarse powder rate.

本発明の金属粉の製造方法は、銅をはじめとする様々な金属や合金、例えば、はんだ粉に適用することができる。具体的には、例えば、広く知られているSn−Pb系、Sn−Pb−Ag系等の鉛を含有するはんだ粉や、Sn−Ag系、Sn−Cu−Ag系、Sn−Zn−Bi系、Sn−Bi系、Sn−Sb系等の鉛を含まないはんだ粉(鉛フリーのはんだ粉)等のはんだ粉の製造に適用できる。   The method for producing metal powder of the present invention can be applied to various metals and alloys including copper, for example, solder powder. Specifically, for example, solder powder containing lead such as the widely known Sn—Pb series, Sn—Pb—Ag series, Sn—Ag series, Sn—Cu—Ag series, Sn—Zn—Bi, etc. It can be applied to the production of solder powder such as solder powder (lead-free solder powder) that does not contain lead, such as Sn-based, Sn-Bi-based, and Sn-Sb-based.

製造する金属粉の平均粒径は特に限定されないが、例えば、10〜70μmである。なお、本発明において、平均粒径は、乾式レーザー回折粒度測定装置(日機装株式会社製、エアロトラックSPR)で平均粒子径を測定した数値である。   Although the average particle diameter of the metal powder to manufacture is not specifically limited, For example, it is 10-70 micrometers. In the present invention, the average particle diameter is a numerical value obtained by measuring the average particle diameter with a dry laser diffraction particle size measuring apparatus (manufactured by Nikkiso Co., Ltd., Aerotrack SPR).

製造する際に使用する遠心噴霧装置は、遠心噴霧法に用いられる一般的な装置でよい。ディスクの材質は一般的なものでよく、カーボンや、セラミックス、Ti、Au、Ni又はFe系の合金が例示でき、具体的には、例えば、炭素鋼(SS)やステンレス鋼(SUS)等を使用することができる。また、ディスクの大きさや形状も特に限定されず、例えば直径10〜100mm程度、形状は、円板状、円錐状、V字形など様々な形状のものを使用することができる。   The centrifugal spraying device used for manufacturing may be a general device used for the centrifugal spraying method. The material of the disk may be a general one, and examples thereof include carbon, ceramics, Ti, Au, Ni, and Fe-based alloys. Specifically, for example, carbon steel (SS) and stainless steel (SUS) are used. Can be used. Further, the size and shape of the disc are not particularly limited, and for example, various shapes such as a disk shape, a cone shape, and a V shape can be used.

ディスクへの熔湯の供給方法も特に限定はなく、滴下でも流下でもよい。また、供給量や供給速度にも特に限定はないが、熔湯を5〜100kg/時間で回転するディスクへ滴下することが好ましい。   There is no particular limitation on the method of supplying the molten metal to the disk, and it may be dropped or flowed down. Further, the supply amount and the supply speed are not particularly limited, but the molten metal is preferably dropped onto a disk rotating at 5 to 100 kg / hour.

上記本発明の金属粉の製造方法を適用することができる遠心噴霧装置例を、図1に基づいて説明する。なお、図1は、遠心噴霧装置の概略断面図である。図1に示すように、遠心噴霧装置10は、内部に噴霧室11が形成されたチャンバ12を有し、モーター13に接続されその駆動により高速回転するディスク14がチャンバ12内の上部である天井部近傍に設けられている。そして、チャンバ12の天井部には、熔湯(金属溶融物)15を保持する熔湯保持部16が設けられている。なお、熔湯15は、溶融炉17でインゴット等を溶融し、熔湯保持部16に導入される。熔湯保持部16は、底部に熔湯15をディスク14上に供給するための熔湯供給部18を有する。この熔湯保持部16及び熔湯供給部18は貫通孔19により連通され、この貫通孔19を通って、熔湯15がディスク14に滴下されるように、熔湯保持部16及びディスク14が配置されている。また、チャンバ12の底面には製造された金属粉を回収する金属粉回収部20が配置されている。   An example of a centrifugal spray apparatus to which the method for producing metal powder of the present invention can be applied will be described with reference to FIG. FIG. 1 is a schematic sectional view of a centrifugal spray device. As shown in FIG. 1, the centrifugal spraying apparatus 10 has a chamber 12 in which a spraying chamber 11 is formed. A disk 14 connected to a motor 13 and rotated at a high speed by the drive thereof is an upper portion in the chamber 12. It is provided near the part. A molten metal holding part 16 for holding a molten metal (metal melt) 15 is provided at the ceiling of the chamber 12. The molten metal 15 is melted into an ingot or the like in the melting furnace 17 and introduced into the molten metal holding unit 16. The molten metal holding part 16 has a molten metal supply part 18 for supplying the molten metal 15 onto the disk 14 at the bottom. The molten metal holding part 16 and the molten metal supply part 18 are communicated with each other through a through hole 19, and the molten metal holding part 16 and the disk 14 are dropped through the through hole 19 so that the molten metal 15 is dropped onto the disk 14. Has been placed. A metal powder recovery unit 20 that recovers the manufactured metal powder is disposed on the bottom surface of the chamber 12.

この遠心噴霧装置10により金属粉を製造する方法の一例を以下に説明する。まず、チャンバ12を排気すると共に、チャンバ12内に窒素、アルゴン等の不活性ガスを充填する。そして、金属インゴット等、原材料をその融点より1〜100℃程度高い温度で溶融炉17にて溶解した熔湯15を、熔湯保持部16に保持させる。この熔湯15を、回転するディスク14の中心に滴下する。ディスク14上に滴下された熔湯15は、遠心力によりディスク14の端側から熔滴21となって噴霧され飛散する。飛散した熔滴21は、チャンバ12内の不活性ガスにより冷却されて、粉末22となってチャンバ12底面へ落下して堆積し、金属粉回収部20で回収される。本発明においては、金属粉回収部20で回収された粉末(金属粉)22の粗粉率を経時的に把握し、その粗粉率に応じてディスク14の回転数を制御する。   An example of a method for producing metal powder by the centrifugal spray device 10 will be described below. First, the chamber 12 is evacuated, and the chamber 12 is filled with an inert gas such as nitrogen or argon. And the molten metal 15 which melt | dissolved raw materials, such as a metal ingot, in the melting furnace 17 at the temperature about 1-100 degreeC higher than the melting | fusing point is hold | maintained at the molten metal holding part 16. FIG. The molten metal 15 is dropped on the center of the rotating disk 14. The molten metal 15 dropped on the disk 14 is sprayed and scattered as a molten liquid 21 from the end side of the disk 14 by centrifugal force. The splashed droplets 21 are cooled by the inert gas in the chamber 12, become powder 22, drop and accumulate on the bottom surface of the chamber 12, and are collected by the metal powder collecting unit 20. In the present invention, the coarse powder rate of the powder (metal powder) 22 collected by the metal powder collection unit 20 is grasped over time, and the rotational speed of the disk 14 is controlled according to the coarse powder rate.

以上説明したように、本発明の製造方法においては、製造された金属粉の粗粉率を測定しながら、又は、あらかじめ同条件で測定しておくことにより、粗粉率の変化を経時的に把握しながら、その粗粉率に応じてディスクの回転数を制御するので、得られる金属粉の粗粉率を確実に安定化させることができ、粒度分布や平均粒径が安定した金属粉を継続的に製造することができる。   As described above, in the production method of the present invention, the change in the coarse powder rate is measured over time by measuring the coarse powder rate of the produced metal powder or by measuring in advance under the same conditions. While grasping, the rotational speed of the disk is controlled according to the coarse powder rate, so that the coarse powder rate of the obtained metal powder can be reliably stabilized, and metal powder with stable particle size distribution and average particle size can be obtained. It can be manufactured continuously.

以下、本発明を下記実施例及び比較例に基づいてさらに詳述する。
(実施例1)
図1に示す遠心噴霧装置10を用いて、平均粒径40μmのはんだ粉が製造されるように、以下の製造条件ではんだ粉を製造した。その際、金属粉回収部20に回収されたはんだ粉の粗粉率を経時的に測定した。噴霧開始からの時間(噴霧時間)に対するはんだ粉の粗粉率の測定結果を、図2に示す。なお、はんだ粉の粒径を乾式レーザー回折粒度測定装置(日機装株式会社製、エアロトラックSPR、ガス圧0.05MPa)を用いて測定し、45μm以上の粒径のはんだ粉が、サンプリングしたはんだ粉全量に占める重量割合を、粗粉率とした。
Hereinafter, the present invention will be further described in detail based on the following examples and comparative examples.
Example 1
Using the centrifugal spray device 10 shown in FIG. 1, solder powder was manufactured under the following manufacturing conditions so that solder powder with an average particle diameter of 40 μm was manufactured. At that time, the coarse powder rate of the solder powder recovered in the metal powder recovery unit 20 was measured over time. The measurement result of the coarse powder ratio of the solder powder with respect to the time from the start of spraying (spraying time) is shown in FIG. The solder powder particle size was measured using a dry laser diffraction particle size measuring device (Nikkiso Co., Ltd., Aerotrack SPR, gas pressure 0.05 MPa), and the solder powder having a particle size of 45 μm or more was sampled. The weight ratio in the total amount was defined as the coarse powder ratio.

<製造条件>
はんだ粉組成・・・Sn−8Zn−3Bi
ディスク・・・材質:炭素鋼、直径:32mm、形状:円板状、回転数:44000rpmで噴霧を開始し、噴霧開始から10時間後に42000rpmに下降させ、噴霧開始から40時間後まで42000rpm(請求項1の「所定の回転数」に相当)で噴霧した後、噴霧開始から40時間後に44000rpmに上昇させた
熔湯の供給量・・・65kg/時間で滴下
熔湯温度・・・210℃
雰囲気・・・窒素雰囲気下
<Production conditions>
Solder powder composition: Sn-8Zn-3Bi
Disc: Material: Carbon steel, Diameter: 32 mm, Shape: Disc shape, Number of revolutions: Start spraying at 44000 rpm, descend to 42000 rpm 10 hours after starting spraying, and 42000 rpm until 40 hours after spraying (invoice) (Equivalent to “predetermined number of revolutions” in item 1) After 40 hours from the start of spraying, the molten metal feed rate was increased to 44000 rpm.
Atmosphere ... under nitrogen atmosphere

(比較例1)
ディスク回転数を44000rpmにせず42000rpmで維持した以外は、実施例1と同様の操作を行った。噴霧時間に対するはんだ粉の粗粉率の測定結果を、図2に示す。
(Comparative Example 1)
The same operation as in Example 1 was performed except that the disk rotation speed was not 44,000 rpm but maintained at 42000 rpm. The measurement result of the coarse powder ratio of the solder powder with respect to the spraying time is shown in FIG.

図2に示すように、ディスク回転数を44000rpm→42000rpm→44000rpmと変化させた実施例1では、粗粉率は30〜35%程度の範囲内で安定し、全工程を通して粗粉率が40%以下のはんだ粉が得られた。一方、ディスク回転数を一定にした比較例1では、噴霧初期は時間の経過と共に粗粉率が下降したが、その後粗粉率は上昇して40%を超え、55時間後には55%程度にまでなった。また、上述のように粗粉の量は実施例1と比較例1とで差があったが、粒径が40μmよりも小さい微粉の量は実施例1と比較例1とでほとんど差がなかった。したがって、粗粉率が安定して低かった実施例1では、比較例1よりも、粒度分布の変化が少なく所望の平均粒径の金属粉を安定して製造できたことが分かった。   As shown in FIG. 2, in Example 1 in which the disk rotation speed was changed from 44000 rpm → 42000 rpm → 44000 rpm, the coarse powder rate was stable within a range of about 30 to 35%, and the coarse powder rate was 40% throughout the entire process. The following solder powder was obtained. On the other hand, in Comparative Example 1 in which the disk rotation speed was made constant, the coarse powder rate decreased with the passage of time in the initial stage of spraying, but then the coarse powder rate increased and exceeded 40%, and after 55 hours, it became about 55%. Until now. Further, as described above, the amount of coarse powder was different between Example 1 and Comparative Example 1, but the amount of fine powder having a particle size smaller than 40 μm was hardly different between Example 1 and Comparative Example 1. It was. Therefore, it was found that in Example 1 in which the coarse powder rate was stably low, metal powder having a desired average particle diameter could be stably produced with less change in particle size distribution than in Comparative Example 1.

また、実施例1及び比較例1とも、55時間経過後は、ディスク削れ、化合物の形成や堆積物の生成が生じ、ディスクが摩耗劣化していた。この結果から、本発明の製造方法によれば、ディスクが摩耗劣化等しても粗粉率が安定しているので、粒度分布を安定化できることが分かった。   In both Example 1 and Comparative Example 1, after 55 hours had elapsed, the disk was scraped, compound formation and deposit formation occurred, and the disk was worn out. From this result, according to the production method of the present invention, it was found that the particle size distribution can be stabilized because the coarse powder rate is stable even if the disk is worn and deteriorated.

遠心噴霧機の概略を示す図である。It is a figure which shows the outline of a centrifugal sprayer. 実施例1及び比較例1のはんだ粉の粗粉率の経時変化を示すグラフである。It is a graph which shows the time-dependent change of the coarse powder rate of the solder powder of Example 1 and Comparative Example 1.

符号の説明Explanation of symbols

10 遠心噴霧装置
11 噴霧室
12 チャンバ
13 モーター
14 ディスク
15 熔湯
16 熔湯保持部
17 溶融炉
18 熔湯供給部
19 貫通孔
20 金属粉回収部
21 熔滴
22 粉末
DESCRIPTION OF SYMBOLS 10 Centrifugal spray apparatus 11 Spraying chamber 12 Chamber 13 Motor 14 Disk 15 Molten metal 16 Molten metal holding | maintenance part 17 Melting furnace 18 Molten metal supply part 19 Through-hole 20 Metal powder collection | recovery part 21 Molten droplet 22 Powder

Claims (4)

高速度で回転するディスク上に熔湯を連続的に供給し遠心力により噴霧させて粉末化する金属粉の製造方法において、前記ディスクを所望の平均粒径の金属粉を得るための所定の回転数で回転させて連続的に金属粉を製造する途中で、前記ディスクの回転数を前記所定の回転数に対して±10%以内の範囲内を条件として、得られる金属粉の粗粉率の下降に応じてディスクの回転数を下降させるか、得られる金属粉の粗粉率の上昇に応じてディスクの回転数を上昇させるかする制御をすることを特徴とする金属粉の製造方法。   In a method for producing a metal powder in which molten metal is continuously supplied onto a disk rotating at a high speed and sprayed by centrifugal force to form powder, the disk is rotated at a predetermined speed to obtain a metal powder having a desired average particle diameter. In the course of continuously producing metal powder by rotating the number, the rotational speed of the disk is within the range of ± 10% of the predetermined rotational speed, the coarse powder rate of the obtained metal powder A method for producing metal powder, characterized in that control is performed to lower the number of rotations of the disk in accordance with the lowering or to increase the number of rotations of the disk in accordance with an increase in the coarse powder rate of the obtained metal powder. 前記ディスクの回転数の制御は、噴霧開始時のディスクの回転数を前記所定の回転数よりも速い回転数とし、得られる金属粉の粗粉率の下降に応じて前記ディスクの回転数を前記噴霧開始時のディスクの回転数よりも下降させて、その後、得られる金属粉の粗粉率の上昇に応じて前記ディスクの回転数を上昇させる制御であることを特徴とする請求項1に記載の金属粉の製造方法。   The control of the number of revolutions of the disk is such that the number of revolutions of the disk at the start of spraying is faster than the predetermined number of revolutions, and the number of revolutions of the disk is set according to the decrease in the coarse powder rate of the obtained metal powder. 2. The control according to claim 1, wherein the control is performed such that the rotational speed of the disk is decreased below the rotational speed of the disk at the start of spraying, and then the rotational speed of the disk is increased in accordance with an increase in the coarse powder rate of the obtained metal powder. Metal powder manufacturing method. 噴霧開始後、前記粗粉率が所定値未満となったら前記ディスクの回転数を前記噴霧開始時のディスクの回転数よりも下降させて、その後、前記粗粉率が前記所定値を超えたら前記ディスクの回転数を上昇させることを特徴とする請求項2に記載の金属粉の製造方法。   After the start of spraying, when the coarse powder ratio becomes less than a predetermined value, the rotational speed of the disk is lowered below the rotational speed of the disk at the start of spraying, and then when the coarse powder ratio exceeds the predetermined value, 3. The method for producing metal powder according to claim 2, wherein the rotational speed of the disk is increased. 前記ディスクを前記所定の回転数で回転させた製造条件で予め粗粉率の経時変化を測定しておき、その測定結果に応じて噴霧開始後所定のタイミングで前記ディスクの回転数を制御することを特徴とする請求項2に記載の金属粉の製造方法。   The change over time in the coarse powder ratio is measured in advance under the manufacturing conditions in which the disk is rotated at the predetermined rotation speed, and the rotation speed of the disk is controlled at a predetermined timing after the start of spraying according to the measurement result. The method for producing metal powder according to claim 2.
JP2007081520A 2007-03-27 2007-03-27 Method for producing metal powder Pending JP2008240059A (en)

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Cited By (3)

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Publication number Priority date Publication date Assignee Title
CN112045197A (en) * 2020-09-15 2020-12-08 湖南天际智慧材料科技有限公司 Rotating disc granulation equipment and production process thereof
JP2021004393A (en) * 2019-06-26 2021-01-14 シンフォニアテクノロジー株式会社 Centrifugal spray device and method of producing fine powder
CN113547127A (en) * 2021-07-20 2021-10-26 成都先进金属材料产业技术研究院股份有限公司 Device and method for preparing spherical metal powder for 3D printing at low cost

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021004393A (en) * 2019-06-26 2021-01-14 シンフォニアテクノロジー株式会社 Centrifugal spray device and method of producing fine powder
JP7319530B2 (en) 2019-06-26 2023-08-02 シンフォニアテクノロジー株式会社 Centrifugal atomizer and method for producing fine powder
CN112045197A (en) * 2020-09-15 2020-12-08 湖南天际智慧材料科技有限公司 Rotating disc granulation equipment and production process thereof
CN113547127A (en) * 2021-07-20 2021-10-26 成都先进金属材料产业技术研究院股份有限公司 Device and method for preparing spherical metal powder for 3D printing at low cost

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