Research On Aluminum Alloy Detection Based On Laser-induced Breakdown Spectroscopy Technology

Laser-induced breakdown spectroscopy(LIBS)has attracted extensive attention at home and abroad for its advantages of rapid analysis,non-destructive testing and long-range detection.Aluminum alloy is one of the most widely used non-ferrous metals in the industry.The application of LIBS technology to the detection of metal elements in aluminum alloys provides a theoretical basis for online monitoring of aluminum alloy smelting,and has practical significance for the detection work in high-risk metallurgical environments.The identification and classification of different grades of aluminum alloys based on LIBS provides a theoretical basis for the sorting technology of aluminum alloy scraps and promotes the sustainable development of renewable non-ferrous metals industry.In order to improve the detection accuracy and reduce the influence of interference factors on the analysis results,the paper carries out spectral preprocessing and establishes qualitative and quantitative analysis models based on LIBS technology combined with chemometrics.Fullspectrum principal component analysis(PCA)of 12 different grades of aluminum alloys is investigated.PLS-DA model and SVM model are established according to eleven characteristic lines,which are selected according to the loading score.Finally,the models are evaluated using the ROC curve.The experimental results show that the AUC parameters and recognition accuracy of SVM model are slightly higher than those of PLS-DA model but the two models both have strong recognition ability for aluminum alloy grades,which proves the feasibility of LIBS combined with chemometrics to identify aluminum alloy grades.The optimal combination of LIBS instrument parameters for quantitative analysis of Mg element and Ti element in aluminum alloy is determined based on response surface methodology(RSM).The spectral data are collected based on the optimal parameters.Using the selected characteristic line as the characteristic variable,the linear regression model,multiple linear regression(MLR)model and partial least squares regression(PLSR)model are established respectively.Finally,compare and analyze the models.The results show that the linear regression model is not stable enough and the prediction results of MLR and PLSR model are ideal.MLR analysis method is more conducive to the portable development of LIBS.