Preparation And Damage Study Of Superhydrophobic Surfaces On Copper Substrate

In recent years,inspired by nature,such as the self-cleaning performance of lotus leaves,the drag reduction effect of shark skin,etc.,the microstructure of materials can change the original surface properties of materials.Metal materials have great value in practical engineering applications.More and more researcher have paid more attention to changing metal surface modification preparations.The application of metal materials has been further expanded.In this paper,the microstructure of copper alloy by WEDM is guided by theory.After chemical etching,the round-shaped microstructure is obtained,and the wettability,corrosion resistance and tribological properties of the microstructure are characterized.The research results are as follows:（1）According to the observation of the experiment,the meniscus at the liquid level above the groove of the trough is found.The simplified contact model can be used to calculate the contact area of the liquid-vapor interface above the groove.According to the prediction formula of the contact angle model,the prediction model of the contact angle of the surface of the trough is obtained..According to the force balance state of the droplet on the surface of the truncated cone,the equilibrium equation is established.According to the critical three-phase contact line density and the minimum height theory of the boss,the influence law of the structural parameters on the surface and the formation of the Cassie state is established.The model establishes the theoretical design criteria for the overall super-hydrophobicity of the circular table microstructure.（2）The orthogonal process of WEDM was used to determine the optimum process parameters for the process.By measuring the intrinsic contact angleθ₀ and the advancing contact angleθ_A of the directly machined surface,combined with the densityρof the water droplet and the surface tension,the super-hydrophobic surface design criterion can be used to determine the diameter x of the upper end of the circular table and the range of the pitch y of the truncated cone.Using the wire electric discharge machining method and the chemical etching method,a circular table sample with a diameter x at the upper end of the circular table and a pitch y of the circular table is prepared,and the static contact angle of the sample is measured to verify the parameter design criteria of the circular table structure.（3）The corrosion resistance of the polished samples,the planar modified samples and the microstructure modified samples were studied by electrochemical workstations,and their polarization curves and AC impedance were measured.The corrosion resistance of superhydrophobic samples,planar modified samples,and polished samples was analyzed from polarization curves and AC impedance.（4）The tribological properties of the microstructure of the other column were studied by the friction and wear tester.The tribological properties of the microstructure on the surface of the material were observed.Due to the bonding strength of the microstructure and the hydrophobic film of the surface,the microstructure could not withstand severe effects in practical applications.Friction and wear,based on the design of Chapter 3,design a slight friction and wear test and durability test to study the wettability change of the microstructure of the round table microstructure after slight wear.After slight wear,it can maintain a good Superhydrophobic properties,microstructural wettability is stable in the atmosphere as well as in acid and alkali environments.