Yeo Reuben J, Bleich Julian N, Guérin Mathilde, Morganella Daniela, Berner Michèle, Frauenrath Holger
Ecole Polytechnique Fédérale de Lausanne (EPFL) Institute of Materials, Lausanne 1015, Switzerland.
Novelis SA Switzerland, Sierre 3900, Switzerland.
Langmuir. 2024 Feb 13;40(6):2872-2882. doi: 10.1021/acs.langmuir.3c02629. Epub 2024 Feb 2.
Aluminum alloys are used in advanced engineering applications as they possess a combination of favorable properties, including high strength, lightweightness, good corrosion resistance, machineability, and recyclability. Such applications often require forming the sheets into the final components, which is typically aided by an oil-based lubricant, followed by joining them using adhesives, which is hampered by residual lubricant. In this work, aluminum surfaces were modified with different self-assembled monolayers (SAMs), with the goal of significantly reducing the amount of lubricant while simultaneously improving friction properties, forming, and bonding performance. Our results show that SAMs terminated with hydrophilic and nucleophilic end groups give rise to high-energy surfaces with wetting properties that are stable over time. These surfaces showed significantly improved surface wetting by the lubricant, which in turn resulted in an improved forming performance at reduced lubricant coat weights. Moreover, the nucleophilic SAM termination provided outstanding performance in adhesive bonding tests under corrosive conditions.
铝合金因其具备多种优良性能，包括高强度、轻质、良好的耐腐蚀性、可加工性和可回收性，而被应用于先进工程领域。此类应用通常需要将板材加工成最终部件，这一过程通常借助油基润滑剂来辅助，随后使用粘合剂将它们连接起来，但残留的润滑剂会对连接造成阻碍。在这项工作中，对铝表面进行了不同自组装单分子层（SAMs）的改性，目的是显著减少润滑剂用量，同时改善摩擦性能、成型性能和粘结性能。我们的结果表明，以亲水性和亲核性端基终止的SAMs会产生具有随时间稳定的润湿性能的高能表面。这些表面显示出润滑剂对其表面润湿性显著改善，进而在降低润滑剂涂层重量的情况下提高了成型性能。此外，亲核性SAM端基在腐蚀性条件下的粘结测试中表现出色。
