激光诱导击穿光谱技术识别航空合金牌号

激光诱导击穿光谱(LIBS)作为一种多元素、高灵敏、非接触式的光谱分析技术,已经被广泛用于钢铁、铝合金等金属材料的定量与定性分析。为将LIBS技术用于航空合金牌号的高准确率识别,对6种不同牌号的航空合金进行了实验测量与分析。实验使用1064nm的Nd∶YAG固体激光器作为激发源,采集了每种合金的100组光谱,每组光谱为100次激光脉冲的平均结果。将得到的航空合金光谱按7∶3的比例划分为训练集和测试集,分别利用全光谱数据和特征谱线数据建立偏最小二乘判别分析(PLS-DA)模型进行航空合金LIBS识别。两种模型得到训练集和测试集的识别正确率均为100%。研究结果表明,LIBS技术与化学计量学结合可以快速准确识别航空合金牌号,且基于特征谱线数据的PLS-DA模型在较少数据输入的情况下可取得与全光谱数据模型相同的结果。实验可为进一步开展航空合金LIBS现场检测工作提供方法参考。

Recognition of aerial alloy grades by laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) has become a popular analytical technique on metal materials such as steel and aluminum alloys for its multi-element, highly sensitive and non-contact measurement. To apply LIBS for high accuracy identification of aerial alloy grades, six different grades of aerial alloys were measured. A 1064nm Nd∶YAG laser was used as the excitation source. 100 sets of spectra for each alloy were collected, and each set of spectra was the average result of 100 laser pulses. The spectra of aerial alloy were divided into training set and test set in ratio of 7∶3. Then the partial least squares discriminant analysis (PLS-DA) model was established to identify the aerial alloy LIBS by full spectrum data and characteristic line data respectively. Both the two models obtained 100% recognition accuracy for the training set and test set. The result showed that the combination of LIBS and chemometrics could identify aerial alloy grades successfully. In addition, the PLS-DA model based on characteristic spectral line data could achieve the same results as the full spectrum data model with less data input. This work could provide a methodological reference for applying LIBS to on-site inspection of aerial alloys.