Electron-Beam Atomic Spectroscopy for In Situ Measurements of Melt Composition for Refractory Metals: Analysis of Fundamental Physics and Plasma Models
Electron-Beam Atomic Spectroscopy for In Situ Measurements of Melt Composition for Refractory Metals: Analysis of Fundamental Physics and Plasma Models
复制标题
用于难熔金属熔体成分原位测量的电子束原子光谱：基础物理和等离子体模型的分析
DOI：
10.1007/s11663-014-0229-2
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
D. Apelian
中科院分区：
文献类型：
--
作者：
Paul Gasper;D. Apelian
电子束 (EB) 熔炼用于加工 Ta、Nb、Mo 和 W 等难熔金属。这些金属具有很高的价值，对许多行业至关重要，包括半导体、航空航天和核工业。电子束熔炼还可以净化二次原料，从而实现这些材料的回收和再循环。目前，还没有在 EB 熔化过程中现场测量熔体成分的方法。 EB 与熔体上方的蒸气碰撞产生的等离子体的光学发射光谱（此处称为电子束原子光谱技术）可用于原位测量熔体成分，从而分析熔体动力学，促进 EB 熔炼工艺的改进，并帮助回收和回收这些关键和高价值金属。本文通过表征电子、离子和中性粒子的密度和能量，并描述它们之间的相互作用，回顾了 EB 撞击产生等离子体的物理原理。然后介绍了几种等离子体模型并分析了它们对此应用的适用性。最后，描述了一种免校准成分测量的潜在方法，并解决了实施的挑战。
Electron-beam (EB) melting is used for the processing of refractory metals, such as Ta, Nb, Mo, and W. These metals have high value and are critical to many industries, including the semiconductor, aerospace, and nuclear industries. EB melting can also purify secondary feedstock, enabling the recovery and recycling of these materials. Currently, there is no method for measuring melt composition in situ during EB melting. Optical emission spectroscopy of the plasma generated by EB impact with vapor above the melt, a technique here termed electron-beam atomic spectroscopy, can be used to measure melt composition in situ, allowing for analysis of melt dynamics, facilitating improvement of EB melting processes and aiding recycling and recovery of these critical and high-value metals. This paper reviews the physics of the plasma generation by EB impact by characterizing the densities and energies of electrons, ions, and neutrals, and describing the interactions between them. Then several plasma models are introduced and their suitability to this application analyzed. Lastly, a potential method for calibration-free composition measurement is described and the challenges for implementation addressed.