民机铝合金蒙皮的激光织构化处理

采用波长为1064 nm的激光表面处理设备在2024-T3铝合金表面刻蚀出平行线、正方形和菱形这3种织构表面。采用扫描电子显微镜与激光共聚焦显微镜观察了不同织构表面的微观形貌。通过测量对水和甘油的接触角来评价它们的浸润性。用拉脱法测试了其表面环氧涂层的附着力。结果表明,在单位面积能量密度相同的情况下,表面织构为正方形和菱形的试样表面粗糙度由处理前的1.9μm分别提升至7.6μm和7.9μm,表现出更好的浸润性,环氧涂层的附着力比未处理试样提高了70%左右,而平行线织构表面的涂层附着力只提高了24%。通过金相观察、强度失效分析及硬度测试发现,织构化处理对飞机蒙皮的力学性能基本没有影响。

Laser texturing of aluminum alloy used as civil aircraft skin

Three different textured surfaces(parallel lines,squares,and diamonds)were etched on the surface of aluminum alloy 2024-T3 using laser beam radiation with a wavelength of 1064 nm.The micro-morphologies of the etched surfaces were observed by scanning electron microscopy and laser scanning confocal microscopy.The wettability of the surfaces was evaluated by measuring their contact angles to water and glycerin.The adhesion of epoxy coatings on the surfaces was tested by pull-off method.The results showed that in the case of the same energy density per unit area,the samples with square and diamond textures had an increase in roughness from 1.9μm(untreated sample)to 7.6μm and 7.9μm respectively,exhibiting better wettability.The adhesion of epoxy coatings on these two textured surfaces was increased by about 70%,while that of the sample with linear textures was only increased by 24%.Through the metallographic observation,strength failure analysis,and hardness testing,it was found that the texturing treatment had a slight effect on the mechanical properties of the aircraft skin.