Achieving superhydrophobicity of Zr-based metallic glass surface with anti-corrosion and anti-icing properties by nanosecond laser ablation and subsequent heat treatment

Abstract

Water repellency of superhydrophobic surfaces offers an opportunity to enhance the corrosion and icing resistance of metallic glasses (MGs). Inspired by the “lotus effect” in nature, hierarchical micro/nanostructures were constructed on a Zr-based MG surface using nanosecond laser ablation. By subsequent heat treatment in air, the structured surface showed a water contact angle (CA) of 168.2 ± 1.5° and a sliding angle (SA) of 4 ± 0.7° (adhesion force of 9.8 ± 1.7 μN), exhibiting repellency and low adhesion to water. Specifically, the superhydrophobic surface stored in air and immersed in water possessed stability and durability, and the superhydrophobic surface still maintained superhydrophobicity after mechanical scratching. The heat treatment temperature worked as a switch for controlling the wettability transition, and by tuning the temperature, the structured surface can switch from superhydrophobicity (CA: 168.2 ± 1.5°) to superhydrophilicity (CA: ~0°). Furthermore, compared to the polished MG surface, the superhydrophobic surface increased the corrosion resistance and freezing time, and delayed the freezing temperature. This study provides a facile non-fluorinated method for fabricating superhydrophobic MG surfaces with anti-corrosion and anti-icing properties, which would enhance the application of MGs as structural and functional materials under extreme conditions.