Investigation of the relationship between arc-anode attachment mode and anode temperature for nickel nanoparticle production by a DC arc discharge
Investigation of the relationship between arc-anode attachment mode and anode temperature for nickel nanoparticle production by a DC arc discharge
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DOI：
10.1088/0022-3727/49/12/125201
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发表时间：
2016-03-31
影响因子：
3.4
通讯作者：
Watanabe, Takayuki
中科院分区：
文献类型：
--
作者：
Liang, Feng;Tanaka, Manabu;Watanabe, Takayuki
在氦弧放电法制备纳米镍的过程中，观察到多种缩窄的电弧-阳极附着模式。电子过热不稳定性导致了多种附着模式的形成。研究了氢气浓度和保护气流量对镍纳米颗粒性能的影响。阳极材料的蒸发速率是形成不同电弧阳极附着物的重要因素。采用双色热法结合高速摄像机，采用适当的带通滤波器，测量了电弧放电过程中电极的表面温度。利用两台同步高速摄像机研究了电弧阳极附着方式与阳极表面温度行为的关系。阳极喷射面积随时间变化的波形与阳极表面最高温度随时间变化的波形一致。当电弧阳极连接由多连接变为窄连接时，阳极最高温度的波动增大。电弧的最高温度波动和稳定性影响了纳米颗粒的尺寸分布。通过控制纳米颗粒生长的停留时间，采用保护气可以获得生产率高、粒径分布窄的纳米颗粒。阐述了不同电弧-阳极附着方式的形成机理。
Multiple and constricted arc-anode attachment modes were observed in helium arc discharge to prepare nickel nanoparticles. The electron overheating instability resulted in the formation of multiple attachment modes. The effects of hydrogen concentration and shield gas flow rate on the characteristics of nickel nanoparticles were investigated. The evaporation rate of anode material contributed to forming different arc-anode attachments. The surface temperature of the electrode was measured during the arc discharge by two-color pyrometry combined with a high-speed camera which employs appropriate band-pass filters. The relationship between the arc-anode attachment mode and the temperature behavior of the anode surface was investigated by using two synchronized high-speed cameras. The waveform of anode jet area variation with time follows that of the highest temperature variation of anode surface with time. The fluctuation of the highest anode temperature increased when the arc anode attachment changed from multiple into constricted mode. The highest temperature fluctuation and stability of the arc contributed to nanoparticle size distribution. Nickel nanoparticles with large productivity and narrow size distribution were obtained when shield gas was employed by controlling the residence time of nanoparticle growth. The formation mechanism of different arc-anode attachment modes was explained.