感应等离子体可通过纯净、 热等离子体的焦耳加热作用, 实现不规则粉末颗粒的球化, 感应等离子体球化在航空航天领域具有广阔的应用前景。 气流温度是感应等离子体球化制粉的关键参数, 等离子体发生器内高温流场温度的空间分布测量为感应等离子体制粉研究和相关工艺改进优化提供了定量依据。 在传统接触式测量手段难以应用于感应等离子体高温流场测量的背景下, 该研究发展了非接触式的发射光谱诊断技术, 开展对100kW高频感应等离子体发生器制备球形钛粉过程中高温等离子体气流的诊断。 通过测量氩气(Ar)在高温下的发射光谱谱线, 结合电动位移扫描技术, 获得了等离子体发生器内某一截面温度的径向空间分布。 研究结果表明: 感应等离子体发生器内径向气流温度的变化呈现马鞍形的变化趋势, 不送粉条件下高温流场待测横截面的中心位置有一个低温区, 温度在(10 120±240) K, 气流最大温度值的区域位于测量横截面圆心的两侧, 靠近趋肤层的位置, 两侧最大温度值分别为(10 500±240)和(10 620±240) K; 相比于不送粉条件, 送入钛粉后感应等离子体发生器内高温流场内温度出现明显变化, 钛粉送入区域下方出现一个明显的倒三角的低温区, 送粉与不送粉下圆心低温区的温差在500 K左右, 趋肤层最大温度区的温差在400 K左右, 显示了颗粒送入被加热的过程中, 附近气流温度也随之出现下降。 发展的测量技术为定量了解感应等离子体球化流场温度二维空间分布提供了成熟的非接触式光谱测试手段。

Inductively coupled plasma (ICP) reactor is able to generate pure thermal plasma and realize sphericalization process of irregular powder particles by joule heating, demonstrating great application prospect in the aerospace industry. Gas temperature is a crucial parameter for inductively coupled plasma spheroidization. Spatial resolved temperature measurement of the high-temperature flow field in the plasma reactor provide quantitatively basis and evidence for theoretical study of plasma spheroidization and industrial methodology optimization. It leads to research gap in flow diagnostics for high-temperature inductively plasma flow owing to the inapplicability of conventional diagnostic techniques. This paper presents in-situ and non-intrusive diagnostics for argon plasma flow in the inductively coupled plasma spheroidization based on optical emission spectroscopy. Spatial-resolved gas temperature in the radial coordinate was measured at a cross section under the powder feed gun by combining argon emission spectroscopy and electric-driving scanning technique. The measured results show that gas temperatures in the radial coordinate showed a saddle-shape trend under no powder-in conditions and the temperature value in the center was (10 120±240) K, while the maximum temperature zone was positioned close to the core with specific values of (10 500±240) and (10 620± 240) K, respectively. There existed obvious temperature difference at the measured cross section under powder -in and no powder-in conditions. A maximum temperature difference under the two conditions was observed to be nearly 500 K and 400 K in the core and the maximum temperature zone respectively, indicating temperature drop of plasma flow when the injected particles were heated. The developed technique in this paper provide a mature method to quantitatively understand the two-dimensional spatial distribution of gas temperature in the inductively plasma spheroidization reactor.