激光去除钢材表面漆层的温度场分析

The temperature field of the laser to remove the paint layer on the surface of the steel

摘要:

为了解决方形平顶脉冲激光去除钢材表面环氧树脂底漆的问题，使用有限元软件建立激光去除钢材表面漆层的数值模型。根据热传导方程和热烧蚀建模理论，对比高斯光束除漆和方形平顶激光除漆效果，探究光斑长度和光斑搭接率对方形平顶激光除漆的影响。研究结果表明：方形平顶光束比高斯光束能量利用率高，切口干净，适用于大范围去除漆层。激光功率为60 W、重复频率为100 kHZ时，烧蚀深度最大值随光斑搭接率增大而增加，热影响区宽度随光斑搭接率增加而减小；烧蚀深度最大值和热影响区宽度随光斑长度增加而减小。在光斑搭接率为30%，光斑长度为100 um参数下，环氧树脂底漆可以很好被去除且表面粗糙度较小。该研究结果可为方形平顶激光加工材料过程提供参考。

Abstract:

In order to solve the problem of epoxy primer removal from steel surface by square flat-top pulsed laser, numerical modelling of laser paint removal from steel surface is established using finite element software. According to the heat conduction equation and thermal ablation modelling theory, comparison of Gaussian beam and square flat-top laser paint removal and investigation of the effect of spot length and spot lap rate on square flat-top laser paint removal. The results show that the square flat-top beam has higher energy utilisation than the Gaussian beam, and makes a cleaner cut, which is suitable for removing paint on a large scale. At a laser power of 60 W and a repetition frequency of 100 kHZ, the maximum ablation depth increased with increasing spot overlap and the width of the heat-affected zone decreased with increasing spot overlap; the maximum ablation depth and the width of the heat-affected zone decreased with increasing spot length. Under the parameters of 30% spot overlap and 100 um spot length, the epoxy primer can be removed well and the surface roughness is small. The results of this study can be used as a reference for the laser processing of square flat top materials.