Laser-induced breakdown spectroscopy as a method for millimeter-scale inspection of surface flatness  

作　　者：Jinrui YE Yaju LI Zhao ZHANG Xinwei WANG Kewei TAO Qiang ZENG Liangwen CHEN Dongbin QIAN Shaofeng ZHANG Lei YANG Xinwen MA 叶晋瑞;李亚举;张朝;王新威;陶科伟;曾强;陈良文;钱东斌;张少峰;杨磊;马新文(Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,People’s Republic of China;Advanced Energy Science and Technology,Guangdong Laboratory,Huizhou 516000,People’s Republic of China;University of the Chinese Academy of Sciences,Beijing 100049,People’s Republic of China;Key Laboratory of Atomic and Molecular Physics&Functional Materials of Gansu Province,College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,People’s Republic of China;Queen Mary University of London Engineering School,Northwestern Polytechnical University,Xi’an 710072,People’s Republic of China)

机构地区：[1]Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,People’s Republic of China [2]Advanced Energy Science and Technology,Guangdong Laboratory,Huizhou 516000,People’s Republic of China [3]University of the Chinese Academy of Sciences,Beijing 100049,People’s Republic of China [4]Key Laboratory of Atomic and Molecular Physics&Functional Materials of Gansu Province,College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,People’s Republic of China [5]Queen Mary University of London Engineering School,Northwestern Polytechnical University,Xi’an 710072,People’s Republic of China

出　　处：《Plasma Science and Technology》2024年第9期148-155,共8页等离子体科学和技术（英文版）

基　　金：supported in part by the National Key Research and Development Program of China(No.2022YFA1602500);National Natural Science Foundation of China program(No.U2241288).

摘　　要：A non-contact method for millimeter-scale inspection of material surface flatness via Laser-Induced Breakdown Spectroscopy(LIBS)is investigated experimentally.The experiment is performed using a planished surface of an alloy steel sample to simulate its various flatness,ranging from 0 to 4.4 mm,by adjusting the laser focal plane to the surface distance with a step length of 0.2 mm.It is found that LIBS measurements are successful in inspecting the flatness differences among these simulated cases,implying that the method investigated here is feasible.It is also found that,for achieving the inspection of surface flatness within such a wide range,when univariate analysis is applied,a piecewise calibration model must be constructed.This is due to the complex dependence of plasma formation conditions on the surface flatness,which inevitably complicates the inspection procedure.To solve the problem,a multivariate analysis with the help of Back-Propagation Neural Network(BPNN)algorithms is applied to further construct the calibration model.By detailed analysis of the model performance,we demonstrate that a unified calibration model can be well established based on BPNN algorithms for unambiguous millimeter-scale range inspection of surface flatness with a resolution of about 0.2 mm.

关 键 词：laser-induced breakdown spectroscopy machine learning surface flatness 

分 类 号：TN249[电子电信—物理电子学]