Spectroscopic studies of conventional and active screen N2–H2 plasma nitriding processes with admixtures of CH4 or CO2
Spectroscopic studies of conventional and active screen N2–H2 plasma nitriding processes with admixtures of CH4 or CO2
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传统和活性屏 N2-H2 等离子渗氮工艺与 CH4 或 CO2 混合物的光谱研究
DOI：
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
J. Röpcke
中科院分区：
文献类型：
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作者：
S. Hamann;K. Börner;I. Burlacov;M. Hübner;H. Spies;J. Röpcke
采用红外吸收光谱和发射光谱（OES）技术研究了用于常规渗氮（CPN）和活性屏渗氮（ASPN）的低气压脉冲直流H2-N2等离子体，其中混合气体为CH 4或CO2。实验在两种模式下进行：（i）内部模型探针处的等离子体，仅由偏置电压驱动，代表CPN方法，以及（ii）仅操作屏幕等离子体，其对应于ASPN实验。结合原位可调谐二极管激光吸收光谱与非原位傅里叶变换红外光谱的甲基自由基和八个稳定的分子，C2 H2，CH 4，C2 H4，CO，CO2，NH 3，HCN和H2O的浓度的演变进行了监测。含碳前体分子的解离度在40%和98%之间变化。甲基自由基的浓度在1011-1012分子cm−3之间。通过分析分子浓度随气体混合物和等离子体功率值变化的发展，发现（i）在甲烷混合物的情况下，C_2H_2、HCN和NH_3是等离子体转化的主要产物;（ii）在二氧化碳的情况下，CO、HCN和NH_3是等离子体转化的主要产物。对于不同的气体混合物和等离子体功率值，测定了甲烷和二氧化碳的裂解效率（RF（CH 4）<$（0.5-4）× 1016分子J−1，RF（CO2）<$（0.5-3.4）× 1016分子J−1）以及各自转化为产物分子的转化效率（RC（product）<$1013 -1015分子J−1）。利用OES测量了屏等离子体的旋转温度，其温度随功率的增加而升高，范围从600 ~ 850 K。同样，随着功率的增加，氮分子的离子成分，即-（0-0）-带的强度，相对于由N2-（0-2）-带表示的中性成分的强度强烈增加。
Low-pressure pulsed dc H2–N2 plasmas with admixtures of CH4 or CO2 used for conventional (CPN) and active screen plasma nitriding (ASPN) were studied by infrared absorption and optical emission spectroscopy (OES) techniques. The experiments were performed in two modes: (i) the plasma at an internal model probe, driven by a bias voltage operated only, representing a CPN approach, and (ii) the screen plasma operated only, which corresponds to an ASPN experiment. Combining in situ tunable diode laser absorption spectroscopy with ex situ Fourier transform infrared spectroscopy the evolution of the concentrations of the methyl radical and of eight stable molecules, C2H2, CH4, C2H4, CO, CO2, NH3, HCN and H2O was monitored. The degree of dissociation of the carbon-containing precursor molecules varied between 40% and 98%. The methyl radical concentration was found to be in the range 1011–1012 molecules cm−3. By analysing the development of molecular concentrations with changes in gas mixtures and plasma power values, it was found that (i) C2H2, HCN and NH3 were the main products of plasma conversion in the case of methane admixture and (ii) CO, HCN and NH3 in the carbon dioxide case. The fragmentation efficiencies of methane and carbon dioxide (RF (CH4) ≈ (0.5–4) × 1016 molecules J−1, RF (CO2) ≈ (0.5–3.4) × 1016 molecules J−1) and the respective conversion efficiencies to the product molecules (RC (product) ≈ 1013–1015 molecules J−1) were determined for different gas mixtures and plasma power values. With the help of OES the rotational temperature of the screen plasma could be determined, which increased with power from 600 to 850 K. Also with power the ionic component of nitrogen molecules, i.e. the intensity of the -(0–0)-band, increased strongly in relation to the intensity of the neutral component, represented by the N2-(0–2)-band.
监测产生粉尘的射频等离子体中的碳氢化合物浓度
影响因子：
3.8
作者：
F. Hempel;D. Lopatik;B. Sikimić;I. Stefanović;J. Winter;J. Röpcke
通讯作者：
J. Röpcke