Corrosion resistance controllable of biomimetic superhydrophobic microstructured magnesium alloy by controlled adhesion

Abstract Super-hydrophobic surfaces have attracted a lot of interest in basic research and application. In this paper, periodic micro-structures of micro-scale papillary-like pits with a different center distance were fabricated on Mg-3Al-1Zn (AZ31) magnesium surface via laser ablation. After being chemical etched by AgNO 3 and surface modified with stearic acid, the as-prepared surfaces showed super-hydrophobic properties and the maximum contact angles reached 158.2°. Besides, a conversion from low adhesion to high adhesion was achieved by adjusting the micro-structure of magnesium alloy. The corrosion resistance of super-hydrophobic surfaces in Cassie state (low adhesion) is better than that in Wenzel state (high adhesion). Compared with bare substrates, the corrosion resistance of as-prepared surfaces was improved significantly according to electrochemical measurements. Moreover, the super-hydrophobic surfaces exhibited excellent chemical and thermal stability at a large range of pH solutions and temperatures. This method can be extended to other engineering materials easily and especially would be used in liquid corrosion and changeable corrosion rate according to requirement in industrial field.