摘要
随着现代工业的发展,复杂加工环境和对象、大动态范围、高效率和高精度激光加工需求愈加迫切,在线监测并实时优化激光加工参数是一条重要的解决途径。与此同时,激光与物质相互作用时可产生与加工参数、加工过程和目标特性密切相关的光信号和表面光学特性变化,在线测量光信号光谱可分析加工过程和状态,故光谱测量有望成为一种重要的激光加工在线监测手段。实际上,光谱测量已应用于激光焊接、激光切割和钻孔、激光清洗打磨、微纳结构制备和增材制造等几乎所有激光加工工艺,具有分辨率高和光谱信息丰富等特点。分析和总结了用于激光加工在线监测的光谱测量技术,包括等离子体光谱、反射光光谱和非线性光信号光谱等。基于单脉冲和多脉冲激光加工激发等离子体信号的光谱测量,除实现化学成分定性和定量监测外,还可以根据特征谱线相对强度变化实时调焦,根据等离子体温度监测和调控激光加工过程中与热效应相关的物理过程;作为一种无损伤且工作距离较远的监测方法,反射光光谱监测可通过测量特定波段反射光信号光谱积分功率、特征谱线和波段位置和强度来有效监测材料表面清洁度、损伤、色度和成分变化等;而在特定条件下产生的谐波信号、荧光信号和拉曼信号等非线性光信号,尽管应用场景有限,但提供了一种实现成分、焦距和材料损伤等监测的新方法。进而,展望了光谱测量在激光加工在线监测上应用的未来发展趋势,包括多种光信号的光谱协同监测与光、声、温度及图像等多种信号测量的复合监测。同时,人工智能技术与在线监测和激光加工的深入结合将进一步推动激光加工技术的智能化发展。
With the development of modern industrial applications,laser processing requirements with complex processing environments and objects,large dynamic range,high efficiency,and high precision are becoming more and more urgent.And the on-line monitoring and real-time optimization of laser processing parameters is an important solution.At the same time,a variety of optical signals and changes in surface optical properties can be generated during the interaction between laser and material.They are closely related to processing parameters,processes,and target properties.Therefore,spectral measurements of corresponding optical signals could reveal the machining process and status,indicating an important on-line monitoring means of laser processing.Spectral measurements with the characteristics of high resolution and rich spectral information have been used for almost all laser processing processes,including laser welding,laser cutting and drilling,laser cleaning and polishing,micro-nano structure preparation,and additive manufacturing.This paper analyzes and summarizes the spectral measurement techniques,including plasma spectroscopy,reflection spectroscopy,and nonlinear optical spectroscopy,applied in on-line monitoring of laser machining.Based on the spectral measurement of plasma signals excited during single and multiple-pulse processing,the qualitative and quantitative monitoring of chemical composition during laser processing can be achieved.In addition,laser focus can be adjusted in real-time according to the relative intensity variances of characteristic peaks.The laser processing processes related to thermal effect can also be monitored and regulated based upon the plasma temperature.As a non-destructive monitoring method over a relatively long distance,reflection spectroscopy can effectively monitor the cleanliness,damages,chroma,and compositional changes of the material surface by measuring the integral spectral power of the reflected light signal a specific band,position and intensity of characteristic spectral peaks and bands.The nonlinear optical signals excited under certain conditions,including the harmonic signals,the fluorescence signals,and the Raman signals,can also provide additional methods of spectral measurements.Although their application scenarios are limited,they provide a new monitoring method for component analysis,focus,and material damage.Furthermore,the future development trend of spectral measurement,including the collaborative monitoring of multiple optical signals,the combined monitoring of spectral,acoustical,temperature and image signals in on-line monitoring of laser processing,has prospected.Meanwhile,the combination of artificial intelligence technology,on-line monitoring and laser processing will further promote the intelligent development of laser processing technology.
作者
胡国庆
管迎春
HU Guo-qing;GUAN Ying-chun(School of Mechanical Engineering and Automation,Beihang University,Beijing 100191,China;Hefei Innovation Research Institute of Beihang University,Hefei 230012,China;National Engineering Laboratory of Additive Manufacturing for Large Metallic Components,Beihang University,Beijing 100191,China)
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2021年第8期2343-2356,共14页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(51705013)
国家重点研究开发计划项目(2018YFB1107400,2018YFB1107700,2016YFB1102503)
北京市自然科学基金项目(3204047)
中国博士后科学基金项目(2019M650423)
安徽省重点研究与开发计划国际科技合作专项(202004b11020030)资助
关键词
光谱测量
激光加工
在线监测
研究进展
Spectral measurement
Laser processing
On-line monitoring
Research process
