Investigation Of Micro And Nano Structure On Titanium Alloy Surface Influences Its Superhydrophobicity

In recent years, inspired from the lotus leaf effect in nature world, people have paid much attention to the fabrication and application of the super hydrophobic materials with water contact angle more than 150°. The super hydrophobic materials reveal its particular advantage in some applied areas ranging from self-cleaning materials, microfluid devices, transport of liquid, vehicle to biomaterials and so on. So the fabricating ways of superhydrophobic material have been developed quickly. However the consistence of material surface superhydrophobicity can't be controlled through those methods. Contrast to other ways, precision and ultra-precision processing technologies can easily guarantee the consistence of surface structure. Acquiring superhydropbic surface through the way of machining will become the focus of research.Wettability of material's surface is an important property governed by both the material's surface energy and the surface's microstructure. Considering the surface energy, it is well known that wetting behavior of material's surface is determined by its outermost molecular-level structure, which is one way to control the wettability of material's surface. The other way to change the wettability is to fabricate microstructure on material's surface. In recent years, with the rapid development of precision and ultra-precision processing technologies, nanoscale fabrication has come true. So the material surface's microstructure can be created by the way of machining. And then the material surface's wettability can be controlled by the modulation of feature and roughness. At last, the superhydrophobic material's surface can be obtained.In this article, based on the theory of superhydrophobicity and lotus leaf effect in nature world, three kinds of microstructure have been designed. These kinds of microstructure make materials gain superhydrophobicity. According to the classical theory of superhydrophobicity, theoretical prediction formulas related to the contact angle on the surface with microstructure were deduced. In accordance with the principle of molecular dynamics, simulation has been made for the hydrophobicity on the surface of titanium dioxide. Microstructure model was established on the surface of titanium dioxide, contrastive simulation has been carried out on the smooth surface and surface with microstructure. Based on the simulation results, the microstructure's influence on the hydrophobicity of material's surface was analyzed.Accordion to the microstructure's model, machine tools and cutting tools were chosen, and reasonable cutting parameters were confirmed. And then NC programs were finished. So the microstructure on the surface of biomedical titanium alloy was gained. This microstructure can make the materials gain hydrophobicity. Practical test and superficial characteristics were made on the titanium alloy's surface with prepared microstructure. The experimental results can tell us how the shape and parameters of the microstructure make influence on material's hydropbicity. So the relationship between the shape and parameters of the microstructure and material's surface contact angel were set up.