Surface Microstructure Regulation And Antifouling Performance Of Titanium Alloy

Titanium alloy has been widely used in navigation,survey,offshore platform and other fields depending on its high specific strength and excellent corrosion resistance.However,due to the excellent biocompatibility of titanium alloy,biofouling is a problem that can not be ignored in the application of marine environment.With the development of science and technology,the methods of antifouling are developing from the methods with biological toxicity and environmental pollution to the methods with broad-spectrum non-toxic,environment-friendly,efficient and long-term.The microstructure of titanium and titanium alloy surface was effectively controlled by hydrothermal and chemical etching methods,and the titanium alloy anti fouling surface with high efficiency of sterilization and anti-algae adhesion was prepared.?1?The influence of hydrothermal parameters on the microstructure of titanium and titanium alloy was studied by hydrothermal method.The effects of hydrothermal temperature and hydrothermal time on the morphology of titanium and its alloys were studied.The results showed that when the hydrothermal time was 4h at 200?,the hydrothermal morphology of titanium was regular and uniform grain with good crystal state.The surface with excellent bactericidal performance was successfully prepared by chemical pretreatment and then hydrothermal treatment in Ag NO₃ solution,and its main bactericidal effect was as follows the oxide of silver that is divided into surface hydrothermal synthesis.?2?Firstly,TiO₂ gel layer with initial structure was prepared on the surface of titanium with H₂O₂/HCl solution,and then hydrothermal treatment was carried out in Na Cl solution to obtain different surface nanostructures.The results show that with the increase of hydrothermal time,Ti O₂ gel layer gradually dissolves and transforms into anatase crystal.The nano-Ti O₂ grains with high specific surface area can effectively adsorb methylene blue in the solution,but the long hydrothermal time can completely dissolve the porous structure on the surface,resulting in the decrease of the surface porosity and thus the decrease of the adsorption capacity.Therefore,the adsorption capacity of the samples with the hydrothermal treatment time of 0.5h is the strongest,while the samples with the hydrothermal treatment time of 1.5h have higher crystallinity and appropriate porosity,and their catalytic capacity is the best.The nano structure and crystallinity of Ti O₂ layer affect the adsorption and catalytic properties of methylene blue.?3?Porous structure was prepared by chemical etching on titanium substrate,and then lubricating oil?silicon oil,fluorocarbon oil?and grease?calcium based grease,fluorocarbon grease?with different viscosity were injected into porous surface to obtain antifouling coating.The antifouling performance of the antifouling surface was evaluated by observing the surface adhesion of three kinds of algae?Chlorella,P.tricornutum and N.exigua?.Algae adhesion experiments show that algae hardly adhere to the antifouling surface injected by lubricating oil,but after immersion in algal liquid for a long time,the liquid lubricating oil is easy to flow out of porous structure,which makes the antifouling effect decrease.However,another housing strategy is shown on the surface of the solid-like grease.After the sample is immersed in the algal solution for a period of time,the algae adhere to the surface and gather together to form a biofilm.However,the adhesion between the biofilm and the grease layer is very low,which is easy to be removed and re exposed to the new grease surface.In addition,the surface injected with grease provides excellent circulation antifouling effect for algae.This simple and long-term antifouling coating has great potential in application.