Engineering of nanoscale antifouling and hydrophobic surfaces on naval structural steel HY-80 by anodizing

Abstract

The impact that biofouling has on a ship’s performance has long been recognized, since it increases the frictional resistance of the hull and can increase the ship’s fuel consumption. In this study, the spectrum of hydrophobic and antifouling surface patterns that can electrochemically be fabricated on HY-80 steel (alloy that is broadly used in shipbuilding for welded hull plates) is examined. After the fabrication of nanoscaled topographies, the optimum conditions for anodizing are determined by correlating the processing conditions with microstructural data. Characterization of the surface oxides was conducted by techniques such as Scanning Electron and Focused Ion Beam microscopy as well as identification of the formed phases by X-ray diffraction techniques. Hydrophobicity of the surfaces was examined by measuring the contact angle of deionized water on the HY-80 steel surface. These studies revealed the improved wetting behavior of the anodized surfaces. Thermogravimetric analysis along with quantitative examination of the biofouling on the specimens were studied after prolonged exposure to seawater and indicated a decrease in the corrosion rate of anodized surfaces.