Titanium Alloy Surface Wettability Regulation And Durability Research

The development of ocean engineering is an essential part to realize the "China dream". However, most of the marine facilities are suffered from the disoperation of marine oil pollution and marine organisms. The bionic research showed that the morphology and wettability of shark-skin surface can reduce adhesion of marine organisms on the surface. Based on the shark-skin effect, through preparation hydrophobic/oleophobic surface with biomimetic microstructure, in order to solve the disoperation of oil pollution and marine organisms for marine facilities. In this paper, taking marine Ti6A14V titanium alloy as base material, using laser machining and sol-gel method coated SiO2, prepared different wettability hydrophobic/oleophobic surface, and then research theirs tolerance for the oil (n-hexadecane) and marine organisms (chlorella). The main research contents and results are as follows:1. Using laser machining constructed grid, linear and dot three kinds of biomimetic microstructure in surface of Ti6A14V, and then by sol-gel method coated SiO2 on the surface of microstructure, at last modified low surface energy to obtain micron, micro-Nano structure surface with different wettability. The experiment results showed that:With space increasing the contact angle decreased. The grid surface is the most difficult to wetting, the followed is linear surface, dot surface is the most easily to wetting. The grid contact angle can up to 161.1°, rolling angle only reach to 0.57 °.2. The microstructure modified low energy and without SiO2 conformed the Wenzel mode, which reached hydrophobic state. However the microstructure with SiO2 conformed conformed the Cassie mode, which reached superhydrophobic state.3. We compared the above-mentioned surface contact angle of water, seawater and oil finding that, modified low energy and without SiO2 microstruture surface contact angle of oil less than 90°, which reached oleophilic state, with SiO2 microstruture surface contact angle of oil greater than 90°, which reached oleophobic state but didn’t reach superoleophobic state. All kinds of surfaces contact angle of water is biggest, the followed is contact angle of seawater, the contact angle of oil is smallest. The research prepared amphiphobicity titanium alloy surface with superhydrophobic and oleophobic, and the contact angle of water can up to 161.1°,the contact angle of oil can up to 106.6°.4. The different wettability surfaces in oil tolerance experiment showed that, after 12 hours in purity 99.9% hexadecane, the wettability of surface with SiO2 and modified low energy changed little, the diminution of contact angle less than 5°, however the diminution of contact angle which surface without SiO2 can up to 20°. The variation of gird contact angle is least, the followed is line contact angle variation, the dot contact angle variation is largest. And with the space decreasing the contact angle variation decreased. The reason is that the bigger contact angle of oil made surface not easily wetted and the surface with SiO2 hold back air to further stop oil from polluting surface.5. The exposure to marine experiment showed that, the organisms adhesion on surface depend on contact angle, the adhesive quantity order was:superhydrophilic dot surface> hydrophilic smooth surface> superhydrophobic dot surface with SiO2. The surface adhesive organisms primarily by the alga, which observed by biomicroscope. The superhydrophobic surface possessed excellent property of resist marine organisms adhesion.6. In order to quantitative research the relationship between different wettability surface and adhesive quantity, further conducted lab chlorella immersion experiment for prepared different wettability surface. The result showed that, the chlorella adhesive quantity order was:dot> line> grid> dot (with SiO2)> line (with SiO2)> grid (with SiO2). which means that with the increasing of contact angle the adhesive quantity of chlorella decreasing.7. Using dynamic flushing experiment to estimate adhesive strength of chlorella, the result showed that, the adhesive strength order was:dot> line> grid> dot (with SiO2)> line (with SiO2)> grid (with SiO2). The surface with smaller roll angle conformed the Cassie mode, its adhesive strength of chlorella was smaller.The research prepared the superhydrophobic/olephobic surface which conformed the Cassie mode and possessed excellent resistant property of oil pollution and marine organisms adhesion.