共查询到18条相似文献,搜索用时 250 毫秒
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采用CO2激光对镀金K9玻璃表面的二甲基硅油污染物进行清洗,在激光器单点作用模式下,分别研究了激光功率和作用时间对清洗效果的影响;并研究了连续扫描工作模式下的激光清洗效果。采用光学显微镜和傅里叶变换红外光谱仪表征激光清洗效果,研究结果表明:通过良好的控制激光参数,采用CO2激光清洗二甲基硅油具有明显的效果;此种非接触式清洗方式可确保K9玻璃表面的金膜完好无损。采用有限元分析软件模拟计算了激光功率和作用时间对清洗过程中温度的影响,计算结果与实验结果规律一致。 相似文献
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用激光清洗金膜表面硅油污染物 总被引:2,自引:0,他引:2
采用CO2激光对镀金K9玻璃表面的二甲基硅油污染物进行清洗,在激光器单点作用模式下,分别研究了激光功率和作用时间对清洗效果的影响;并研究了连续扫描工作模式下的激光清洗效果。采用光学显微镜和傅里叶变换红外光谱仪表征激光清洗效果,研究结果表明:通过良好的控制激光参数,采用CO2激光清洗二甲基硅油具有明显的效果;此种非接触式清洗方式可确保K9玻璃表面的金膜完好无损。采用有限元分析软件模拟计算了激光功率和作用时间对清洗过程中温度的影响,计算结果与实验结果规律一致。 相似文献
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随着超快激光“冷加工”技术的发展,超快激光逐渐开始应用于文物保护领域。针对古城墙文物表面污染物清洗的应用需求,制作类城墙的大理石文物及表面污染物模拟样品,进行基于皮秒激光的文物样品清洗实验研究,并与纳秒激光清洗的效果进行对比。实验中采用共聚焦显微镜观测和荧光能谱仪成分分析等手段,改变激光输出能量,清洗次数和扫描速度等激光清洗参数,在不损伤大理石基底并综合考虑清洗效率和清洗效果基础上,寻找优化实验参数。实验发现皮秒激光清洗优化参数为激光功率18W,扫描速度1000mm/s,清洗次数8次。清洗后主要污染物硫元素占比下降94.57%,清洗后区域表面粗糙度为1.267μm。综合考虑清洗后污染物成分占比、表面粗糙度等方面,皮秒激光清洗大理石文物样品的整体效果优于纳秒激光清洗区域。 相似文献
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研究了超声清洗和激光预处理两种后处理手段对减反膜的损伤特性的影响。采用电子束蒸发技术制备了1 064 nm减反膜,利用超声清洗及激光预处理的方法分别对样品进行处理,并对处理前后的样品分别进行激光损伤阈值测试及破斑深度测量。结果表明:处理后减反膜的损伤阈值均有所提升,但激光预处理的阈值增强效果更加明显;超声清洗前后的破斑深度没有大的变化,而激光预处理后的破斑深度比处理前浅得多;原因在于超声清洗只能去除表面杂质,激光预处理可减少和抑制膜层内较深处的缺陷。 相似文献
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In-process monitoring techniques for laser cleaning 总被引:1,自引:0,他引:1
Diverse in-process monitoring techniques based on acoustic, chromatic and intelligent approaches have been developed for laser cleaning not only to achieve the sound-cleaned surface but also to control the process in an automatic manner. The cleaning of various materials such as copper, marble, paper have also been carried out by using Q-switched Nd:YAG radiation. The process was successfully monitored by detecting the acoustic emission induced by laser–surface interactions during laser cleaning. Novel surface monitoring was achieved by chromatic modulation technique. The monitoring of laser fluence based on neural network logic was carried out by means of the recognition of acoustic spectrum patterns. The prediction system of surface damage has been also developed using fuzzy rule base in the same way as a human expert. These techniques may provide unique information for characterising the process as well as a promise of successful applications for laser cleaning techniques in real practical fields. 相似文献
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Yayun Ye Yang Qi Xiaodong Yuan Xia Xiang Haijun Wang Weiqiang Zhou Xiaofeng Cheng Xiaoyu Luan Runping Zhang 《Optik》2014
Laser cleaning is firstly used to remove the contaminations on the sandstone surfaces in Yungang Grottoes. A Q-switched Nd:YAG laser operated at 1064 nm with a pulse width of 10 ns is used to perform the experiments. Before experiments in Yungang Grottoes, the laboratory experiments on sandstone samples obtained from Shanxi province have been conducted. The laser induced damage thresholds of the uncontaminated sandstones and the laser cleaning thresholds of ink contaminated sandstones have been obtained in the laboratory. The difference between the cleaning effects of dry laser cleaning and steam laser cleaning has been compared. On the basis of the laboratory experimental data, the experiments in Yungang Grottoes have been conducted and the results indicate that laser cleaning is safe and effective for removal of graffiti ink and black smudges of smoke. 相似文献
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This paper presents part of the larger study on microstructural features of mortars and it's effects on laser cleaning process. It focuses on the influence of surface roughness, porosity and moisture content of mortars on the removal of graffiti by Nd:YAG laser. The properties of this laser are as follows: wavelength (λ) 1.06 μm, energy: 500 mJ per pulse, pulse duration: 10 ns. The investigation shows that the variation of laser fluence with the number of pulses required for the laser cleaning can be divided into two zones, namely effective zone and ineffective zone. There is a linear relationship observed between number of pulses required for laser cleaning and the laser fluence in the effective zone, while the number of pulses required for the laser cleaning is almost constant even though the laser fluence increases in the ineffective zone. Moreover, surface roughness, porosity and moisture content of mortar samples have influence on the laser cleaning process. The effect of these parameters become however negligible at the high level of laser fluence. The number of pulses required for the laser cleaning is low for smooth surface or less porous mortar. Furthermore, the wetness of the samples facilitates the cleaning process. 相似文献
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A laser shock cleaning is a new dry cleaning methodology for the effective removal of submicron sized particles from solid surfaces. This technique uses a plasma shock wave produced by laser-induced air breakdown, which has applied to remove nano-scale silica particles from silicon wafer surfaces in this work. In order to characterize the laser shock cleaning process, acoustic waves generated during the shock process are measured in real time by a wide-band microphone and analyzed in the change of process parameters such as laser power density and gas species. It was found that the acoustic intensity is closely correlated with the shock wave intensity. From acoustic analysis, it is seen that acoustic intensity became stronger as incident laser power density increased. In addition, Ar gas has been found to be more effective to enhance the acoustic intensity, which allows higher cleaning performance compared with air or N2 gas. 相似文献
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高功率脉冲TEA CO2激光除漆的研究 总被引:3,自引:0,他引:3
选用高功率脉冲TEA CO2激光器,对不同颜色不同种类的油漆进行了清洗实验,运用数码照片分析程序计算出清洁率,找出了完全清洗阈值和损伤阈值.实验结果较为清晰地给出了激光输出能量和重复频率对清洗效果的影响.对红色醇酸漆来说,完全清洗阈值为10.37J/cm2,而损伤阈值为11.43 J/cm2;红色金属喷漆的完全清洗阈值为9.66 J/cm2,其损伤阈值达10.37 J/cm2;黄色金属喷漆的完全清洗阈值为10.71 J/cm2,损伤阈值则为11.07 J/cm2.输出能量和重复频率未达指定参数时,激光清洗清洁率则低于100%. 相似文献
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Yayun Ye Xiaodong YuanXia Xiang Wei DaiMeng Chen Xinxiang MiaoHaibing Lv Haijun WangWanguo Zheng 《Optics and Lasers in Engineering》2011,49(4):536-541
A Nd:YAG laser (1064 nm) induces optical breakdown of the airborne above the gold-coated K9 glass surface and the created shockwave removes the SiO2 particles contaminated on the gold films. The laser cleaning efficiency has been characterized by optical microscopy, dark field imaging, ultraviolet-visible-near infrared spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and the Image-pro software. The relationships between removal ratio and particle position and laser gap distance have been studied in the case of single pulse laser cleaning. The results show that the 1064 nm laser induced plasma shockwave can effectively remove the SiO2 particles. The removal ratio can reach above 90%. The effects of particle position and laser gap distance on the cleaning efficiency are simulated for the single pulse laser cleaning. The simulated results are consistent with the experimental ones. 相似文献
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铝合金焊接技术在工业生产、制造和维修等领域有广泛的应用,焊缝内存在气孔导致焊接质量降低是铝合金焊接技术的常见问题。由于铝合金表面金属氧化物是导致气孔生成的主要来源,对激光清洗过程进行在线检测,不但可以实时分析表面氧化物的清洗状态,而且可以避免基体表面因为过度清洗造成损伤或二次氧化。提出采用激光诱导等离子体光谱(LIBS)在线检测铝合金焊前激光清洗过程,表征清洗后铝合金基体的表面状态。LIBS技术可以对多元素成分同时检测,拥有较低的检出限和较高的准确性。搭建基于Andor Mechelle 5000光谱仪的铝合金焊前激光清洗在线检测系统,剔除空气环境对实验结果的影响,测试6061铝合金表面氧化物和铝合金基体的LIBS光谱,分析两者独特的元素特征谱线,采用X射线能谱(EDS)测试结果验证元素特征谱线的准确性,并探讨激光清洗过程LIBS技术在线检测的可行性。实验测试等离子体光谱谱线强度与激光能量密度之间的关系,获得单次脉冲激光去除铝合金表面氧化物的损伤阈值,结合X射线能谱的检测结果研究激光损伤阈值的成因及影响。研究激光清洗过程等离子体光谱特征谱线与脉冲次数之间的关系,提出基于O/Al特征谱线强度比值作为在线检测清洗效果及二次氧化损伤的评判依据。为验证该评判依据的准确性,将O/Al特征谱线强度比值随清洗次数的变化趋势与X射线能谱测试获得的氧元素原子百分比变化趋势进行对比。实验结果表明:采用200~700 nm范围内激光诱导等离子体谱线特征分析激光清洗状态,可以剔除空气环境的影响;氧元素和铝元素特征谱线准确反映出表面氧化膜与铝合金基体的成分差异;X射线能谱检测元素成分和含量表明氧元素含量随着激光清洗能量密度先减后增,单次清洗铝合金的二次氧化损伤的激光能量阈值为11.46 J·cm-2,小于损伤阈值的激光能量密度对铝合金基体的多次清洗未造成损伤,等离子体光谱特征谱线强度与表面清洗状态相关, 656.5 nm(OⅡ)/396.2 nm(AlⅠ)谱线强度比值≤1.5%为激光清洗干净的依据。研究结果有利于铝合金的激光清洗实时控制技术和焊接装置集成化。 相似文献