特种镁合金熔炼过程稀土元素的激光诱导击穿光谱在线检测方法

In the development process of the speccial magnesium alloys containing rare-earth elements (REEs), REEs are easily oxidized and lost in the smelting process due to very active chemical properties. Additionally, the lack of online rapid detection method results in the difficulty of the compositional content control, long development cycle, and high cost. This project proposes the methods of online compositional analysis of REEs in smelting process of magnesium alloys using laser-induced breakdown spectroscopy (LIBS) technique. This research includes the laser-induced breakdown spectroscopy sensor of melt magnesium alloys, influence of environmental factors to plasma signal and sensor optimization, and high-precision online quantitative analysis method of REEs in molten magnesium alloys. The proposed research framework and many methods are innovative: to develop the LIBS sensor of REEs in molten magnesium alloys, and to propose the highly integrated program of the immersed probe combined with the long distance convergence of double pulse laser and the plasma light collection, in order to solve the problem of the protection of optics in online application; to propose the method of reducing noise based on the program of image binary mask, and the dynamic calibration method integrating the non-standard and standard models, and these methods will have an important effect for improving the quantitative measurement accuracy. The research results supported by this project, will greatly shorten the developing cycle of new special magnesium alloys, and provide an important strategy for the precise online compositional control of REEs.

在稀土特种镁合金研制过程中，由于稀土元素化学性质活跃，冶炼过程中极易氧化烧损，且缺乏在线快速检测方法，导致稀土元素含量难以精准控制，致使合金研制周期长、成本高，成为制约稀土特种镁合金研制与应用的重要难题。本项目提出基于激光诱导击穿光谱技术的熔体镁合金稀土元素在线检测方法，研究内容包括：熔体镁合金的激光诱导击穿光谱传感器；环境因素对等离子体信号的影响及传感器优化；稀土镁合金在线高精度定量分析方法。本项目研究方案和方法具有如下创新性：拟研制出熔融态稀土镁合金的LIBS传感器，提出等离子体远距离激发和等离子体光远距离收集的浸入式探头高度集成方案，将解决传感器在线应用光学元件保护困难的难题；提出基于图像二值掩码的降噪方案及无标与有标模型相融合的动态标定方法，可显著提高定量化分析精度。本项目将极大缩短新型特种镁合金的研制周期，为稀土特种镁合金的成分在线精确控制提供重要技术支持。

在稀土特种镁合金研制过程中，由于稀土元素化学性质活跃，冶炼过程中极易氧化烧损，且缺乏在线快速检测方法，导致稀土元素含量难以精准控制，致使合金研制周期长、成本高，成为制约稀土特种镁合金研制与应用的重要难题。本项目提出基于激光诱导击穿光谱技术的熔体镁合金稀土元素在线检测方法，主要研究内容包括：熔体镁合金的激光诱导击穿光谱传感器；环境因素对等离子体信号的影响及传感器优化；稀土镁合金在线高精度定量分析方法。本项目研制了一套远距离、高灵敏熔体镁合金的激光诱导等离子传感器；总结了熔体镁合金中稀土元素的LIBS 发射光谱特征，给出了最佳分析谱线表，丰富了LIBS 发射光谱分析数据库；提出了一种谱线特征自动提取方法，简化了特征谱线选取过程，并提高了定量分析性能；建立了熔体镁合金稀土元素在线检测的整套系统方法和解决方案。本项目将极大缩短新型特种镁合金的研制周期，为稀土特种镁合金的成分在线精确控制提供重要技术支持。