Electrochemical fabrication of superhydrophobic passive films on aeronautic steel surface

Aeronautic steel is widely used as the structural material in aircrafts. The inherent hydrophilicity of aeronautic steel will result in water clinging and ice adhesion in humid environment, which seriously affect the stability of aircrafts. Therefore, fabrication of superhydrophobic surface on aeronautic steel substrate has considerable industrial significance in improving its service life in humid environment. However, how to introduce super-hydrophobicity on the aeronautic steel surface has been rarely focused. Herein, a facile electrochemical etching method was applied for forming passive films on 30Cr2Ni2WVA aeronautic steel surface, and the reduction of surface energy was achieved by fluoroalkylsilane modification. Experimental studies were implemented to investigate the influences of electrochemical process parameters on the wettability of prepared surfaces, and the relatively optimum technical parameters were obtained through comparative analysis of experimental results. The robustness of the superhydrophobic surface covered with passive films was carefully investigated by carrying out different tests including linear abrasion, solid particle impact, ultrasonic cleaning, ultraviolet exposure and thermal cycling. Additionally, we also studied the anti-icing property of the superhydrophobic surface.