Aluminum and stainless steel base bionic super-hydrophobic surface preparation technology using in space instruments

For superior performances as waterproof, antifouling, corrosion resistance and resistance reduction of bionic super-hydrophobic surface, liquid floated gyroscope could further improve the measurement accuracy with the rotor speed acceleration by using the resistance reduction effect of super-hydrophobic surface. Firstly, the method of combining high current electrochemical etching with surface fluoridation was adopted. The pyramidal micro-nano composite structure was quickly constructed through the dissolution and collapse of alumina nanowire on the surface of aluminum during the high current oxidation process. The contact angle between water droplets and the structure could reach 160±1°. The effects of etching time and current density on surface topography and hydrophobicity were investigated then the preparation process of chemical and electrochemical etching method combined with surface fluoridation was adopted in super-hydrophobic process of stainless steel basement. The micron-structure was etched by hydrochloric acid and hydrogen nitrate mixed solution; then the nano-structure was obtained through electrochemical anode oxidation in perchloric acid. The micro-nano composite structure with ultra-sparse properties was formed. The surface contact angle can be increased to 151±1°. The paper mainly studied the method of preparing superhydrophobic surface materials and discussed the influence of etching time, solution concentration and voltage on the surface morphology and the superhydrophobic properties of materials.