Abstract

The effect of laser treatment of aluminum samples on the properties of the surface hydroxide oxide layer is studied. It is shown that treatment in air leads to an increase in the thickness of the oxide layer and the almost complete disappearance of hydroxide forms, which results in deterioration of the protective properties of this layer due to its higher defectiveness and porosity. It is found that the optimal treatment regime for aluminum, the surface of which is covered by an oxide layer with a significant fraction of hydroxides, is laser irradiation in an inert argon gas medium with small (1–2 vol %) oxygen content. Laser treatment leads to the formation of a protective surface layer that effectively inhibits the anodic dissolution of aluminum in a model corrosion medium, borate buffer solution at pH 7.4. It is shown that the initial hydroxide oxide film and the oxide film formed during laser treatment processing are hydrophilic, that is, they are well moistened with water. The surface treatment of aluminum in the initial state and after laser irradiation with a solution of vinyltriethoxysilane (VTES) leads to the formation of a hydrophobic adsorption layer and a significant decrease in the currents of anodic dissolution. Using X-ray photoelectron spectroscopy, it is shown that silane adsorption occurs both with the participation of silicon atoms and carbon atoms of an alkene bond. The hydrophobic layer of adsorbed silane on the laser-treated surface has a greater thickness and has a higher inhibiting effect on the anodic dissolution of aluminum than in the case of the initial aluminum surface.

中文翻译：

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激光处理和疏水化对铝腐蚀电化学行为的影响

摘要

研究了铝样品的激光处理对表面氢氧化物层性能的影响。结果表明，在空气中进行处理会导致氧化层厚度增加，氢氧化物几乎完全消失，由于其缺陷和孔隙率较高，导致该层的保护性能下降。已经发现，铝的最佳处理方式是在氧含量低（1-2％（体积））的惰性氩气介质中进行激光辐照，铝的表面被氧化物层覆盖着大量的氢氧化物。激光处理导致形成保护性表面层，该保护性表面层可有效抑制铝在模型腐蚀介质（pH 7.4的硼酸盐缓冲溶液）中的阳极溶解。可以看出，初始的氢氧化物氧化膜和在激光处理过程中形成的氧化膜是亲水的，也就是说，它们被水充分润湿。在初始状态下以及在用乙烯基三乙氧基硅烷（VTES）进行激光辐照之后，对铝进行表面处理会导致形成疏水吸附层，并显着降低阳极溶解电流。使用X射线光电子能谱，表明硅烷吸附是在烯烃键的硅原子和碳原子的参与下发生的。与初始铝表面相比，在激光处理过的表面上吸附的硅烷的疏水层具有更大的厚度，并且对铝的阳极溶解具有更高的抑制作用。