铝合金蒙皮表面漆膜去除工艺对比研究

Comparative study of paint removal processes for aluminum alloy skin surface

为对比不同工艺去除铝合金蒙皮表面漆膜的效果及对基体材料的影响,分别采用机械打磨法、喷砂除漆法以及激光除漆法去除铝合金蒙皮表面的漆层,使用扫描电镜、激光共聚焦显微镜、拉曼光谱仪对除漆效果进行了表征。结果表明,机械打磨所用的SiC磨粒不仅会嵌入除漆表面,还会破坏漆层聚合物的化学结构,导致Si、N-H、-CH含量显著增大,无法避免基底损伤。喷砂除漆法的喷砂压力从0.1 MPa分别增大至0.3 MPa、0.5 MPa后,除漆表面冲击凹坑直径增大,表面粗糙度由7.89μm分别增大至14.27μm、13.29μm,误差较大,无法保证再喷漆的工艺质量。激光除漆法可以精细化控制除漆进程,将热输入量控制为50.4 J/cm^(2)时,表面漆层几乎完全去除,且基底表面未见明显损伤。本研究证明,激光除漆作为新兴除漆工艺,具备高效、参数可控、可实时监控等优势,在工业领域具有一定应用价值及发展潜力。

In order to compare the effects of different processes to remove the paint film on the surface of aluminum alloy skin and the effects on the substrate material,the paint layer on the surface of aluminum alloy skin was removed by mechanical sanding,sandblasting and laser paint removal methods,respectively.Scanning electron microscope,laser confocal microscope and Raman spectrometer were used to characterize the paint removal effect.The results show that the SiC abrasive particles used in mechanical sanding not only embedded in the paint removal surface,but also damaged the chemical structure of the paint layer polymer,resulting in a significant increase in the content of Si,N-H,and-CH,which could not avoid the substrate damage.After the sandblasting pressure of sandblast paint removal method was increased from 0.1 MPa to 0.3 MPa and 0.5 MPa,the diameter of the impact crater on the surface of the paint removal increased and the surface roughness increased from 7.89μm to 14.27μm and13.29μm respectively,which resulted in a large error that could not guarantee the process quality of the repainting.The laser paint removal method could finely control the paint removal process,and when the heat input was controlled to be 50.4 J/cm^(2),the surface paint layer was almost completely removed and there was no obvious damage to the surface of the substrate.This study proves that laser paint removal as an emerging paint removal process has the advantages of high efficiency,controllable parameters,real-time monitoring,etc.,and has certain application value and development potential in the industrial field.