激光清洗5083铝合金表面漆层的数值模拟与试验研究

Numerical simulation and experimental study on laser cleaning of 5083 aluminum alloy surface paint layer

为了探索不同功率的激光对铝合金表面漆层的温度场分布以及清洗深度的影响,以及光斑搭接率对清洗效果的影响,利用COMSOL multiphysics软件建立了光纤脉冲激光清洗5083铝合金表面漆层的数值模型,最后得既能够防止基体表面受到损坏,也能够使得漆层材料完全去除的激光功率,以及可以获得良好清洗效果的光斑搭接率,并用实验来得以验证。结果表明:激光重复频率为100 kHz时,激光功率越大,试样表面温度上升越快,烧蚀深度也随之增加。当30 W的激光功率基本上可以保证去除掉漆层且不伤及基体表面,对基体材料的烧蚀深度为10μm。在激光功率为30 W,光斑搭接率为50%的实验参数下,试样表面粗糙度较清洗前降低,为4.48μm,在该实验参数下可以获得不伤及铝合金基体的良好的清洗效果。该实验结果可以为光纤脉冲激光清洗的工艺参数的选择提供参考。

In order to explore the influence of different power lasers on the temperature field distribution and cleaning depth of the aluminum alloy surface paint layer,as well as the effect of the spot overlap rate on the cleaning effect,the COMSOL multiphysics software is used to establish a numerical model of 5083 aluminum alloy surface paint layer with fiber pulse laser cleaning.Finally,the laser powers that can not only prevent the substrate surface from being damaged,but also make the coating material completely removed,as well as the spot lap ratio that can obtain good cleaning effect,are verified by experiments.The results show that when the laser repetition frequency is 100 kHz,the greater the laser power,the faster the temperature of the sample surface rises,and the ablation depth also increases.When the laser power of 30 W can basically ensure that the paint layer is removed without damaging the surface of the substrate and the ablation depth of the substrate material is 10μm.Under the experimental parameters with laser power of 30 W and spot overlap rate of 50%,the sample surface roughness is reduced to 4.48μm before cleaning.Thus,a good cleaning effect without damaging the aluminum alloy substrate can be obtained.The experimental results can provide a reference for the selection of process parameters of fiber pulse laser cleaning.