ABSTRACT

The aim of this study was to investigate the influence of laser treatments with varying energy density and wavelength on the surface structure, shear strength and fracture behavior of hybrid compounds of thermoset carbon fiber-reinforced polymer (CFRP) and aluminum (Al) bonded with three different structural adhesives. The CFRP was pretreated by laser with near-infrared (NIR) and ultraviolet (UV) wavelengths and applying different energy densities. Aluminum surfaces were structured with NIR. Reference CFRP/Al-specimens were prepared by acetone cleaning, low pressure oxygen/argon plasma or sand blasting. The surfaces were investigated microscopically before bonding and after mechanical testing. In addition, the surfaces were examined with white light interferometer and sessile droplet test methods. The bonded compounds were characterized in standardized single lap shear tests to reveal the influence of the pretreatment strategies on the joint strength. Suitable process windows for laser pretreatments were identified, including NIR-pretreatment methods that can compete with an UV-laser source. For every adhesive, a suitable pretreatment method was found.

摘要

本研究的目的是研究不同能量密度和波长的激光处理对热固性碳纤维增强聚合物 (CFRP) 和铝 (Al) 与三种键合的混合化合物的表面结构、剪切强度和断裂行为的影响。不同的结构粘合剂。CFRP通过具有近红外（NIR）和紫外（UV）波长并应用不同能量密度的激光进行预处理。铝表面采用 NIR 进行结构化。通过丙酮清洗、低压氧/氩等离子体或喷砂制备参考 CFRP/Al 试样。在粘合之前和机械测试之后对表面进行显微镜检查。此外，用白光干涉仪和固着液滴测试方法检查表面。在标准化的单搭接剪切试验中对粘合化合物进行了表征，以揭示预处理策略对接头强度的影响。确定了适合激光预处理的工艺窗口，包括可以与紫外激光源竞争的 NIR 预处理方法。对于每种粘合剂，都找到了合适的预处理方法。