超疏水铝合金表面的制备及耦合机理分析

为制备超疏水铝合金表面，采用高速电火花切割技术在铝合金表面加工类水稻叶表面的沟槽结构。通过扫描电子显微镜(SEM)观测材料表面形貌，采用接触角测量仪表征水滴在材料表面的疏水性和黏附性。结果表明： 铝合金表面形成了排列规则的微米级沟槽结构，沟槽突起和底部覆盖着微米级凹坑、突起物和纳米级错层等结构。铝合金试样表面的接触角由加工前的61.24°提高至157.71°，最大达165.36°，实现了材料表面亲水向超疏水的转变。提拉法表明加工的铝合金表面具有高黏附特性。将测得的接触角与CassieBaxter模型计算的理论值进行比较，发现试样表面的超疏水性是微米级和纳米级等复合结构共同耦合作用的结果。铝合金试样表面的多尺度结构不仅提高了材料表面的疏水性能，同时也形成了试样表面的高黏附特性。

Fabrication and Coupling Mechanism of Super-hydrophobical Aluminium Alloy Surface

To fabricate superhydrophobic aluminum alloy surface, bionic groove structure of rice leaf on the aluminum alloy surface was copied by means of high speed wire cut electrical discharge machine. The surface morphologies, structure, wettability and adhesion of the aluminum alloy surface were studied using scanning electronic microscope (SEM) and the interface contact angle was measured,respectively. The results show that surface consists of microscale grooves in a regular arrangement covered by microscale pits, processes and nanoscale staggered floor structure. The wettability of the surface changes from hydrophilicity (the contact angle is 61.24°) to superhydrophobicity (the contact angle is 157.71°), and the biggest contact angle of the resulting surface reaches 165.36°. Czochralski method shows that the specimen surface is highadhesive. By comparing the experimental results with that from the theoretical Cassie model, it can be found that the superhydrophobic surface of the specimen is the coupling result of micro and nanoscale composite structures. Multiscale structures of aluminum alloy surface not only improve the hydrophobic properties, but also form the highadhesion properties of material surface.