PDF(Pubmed)
Abstract：
The obvious advantages of laser paint removal technology make it a viable alternative to traditional paint removal methods. Infrared nanosecond laser was used to remove paint from car body. The microstructure, composition, surface roughness, hardness and ablative products of the samples were analyzed. The effect of the process combination of laser defocus distance and ambient atmosphere (ambient air, compressed air and inert atmosphere) on the substrate damage and the paint removal effectiveness was explored, and the related mechanism was discussed. Defocus not only changed the fluence of laser spot but also increased the spot diameter. The effect of defocused laser paint removal on the paint and substrate was caused by the superposition of these two factors. The results show that the laser with defocus distance of +4 mm effectively removed the paint in inert atmosphere and has the least adverse effect on the substrate. The content of C element and organic components on the substrate surface was the lowest, and its surface roughness and hardness was very close to the uncoated substrate. Focused laser paint removal in ambient air caused the most serious damage to the substrate. Its surface microhardness increased by 11 HV, and the influence depth reached 37 µm. The mechanism of laser paint removal without auxiliary gas is the superposition of laser plasma effect, laser gasification effect and thermal stress effect. In open atmosphere (compressed air and inert atmosphere), the mechanism of laser paint removal is laser gasification effect and thermal stress effect. This research can provide practical references and theoretical basis for the large-scale industrial application of low/non-damage laser paint removal technology.
摘要：
激光除漆技术的明显优势使其成为传统除漆方法的可行替代方案。红外纳秒激光用于去除车身油漆。微观结构,composition,表面粗糙度,分析了样品的硬度和烧蚀产物。激光散焦距离和环境大气(环境空气，压缩空气和惰性气氛)对基材损伤和油漆去除效果进行了探索，并对相关机理进行了探讨。散焦不仅改变了激光光斑的通量，而且增加了光斑直径。散焦激光除漆对油漆和基材的影响是由这两个因素的叠加造成的。结果表明，散焦距离为+4mm的激光在惰性气氛中有效去除油漆，对基材的不利影响最小。基板表面的C元素和有机组分的含量最低，其表面粗糙度和硬度非常接近未涂覆的基材。集中激光在环境空气中去除油漆对基材造成了最严重的损害。其表面显微硬度增加了11HV，影响深度达到37µm。无辅助气体激光除漆的机理是激光等离子体效应的叠加，激光气化效应和热应力效应。在开放气氛中（压缩空气和惰性气氛），激光除漆的机理是激光气化效应和热应力效应。该研究可为低/无损伤激光脱漆技术的大规模工业应用提供实践参考和理论依据。
