Subtractive manufacturing of stable hierarchical micro-nano structures on AA5052 sheet with enhanced water repellence and durable corrosion resistance

Abstract

Preparing super-hydrophobic surfaces with additive manufacturing (AM) and multi-step processes improves corrosion resistance of Al alloys. But the incorporation of dissimilar metals accelerates matrix corrosion, additive polymers cannot offer a long-term structural stability, and multi-step methods are complicated and costly. Hereon, stable micro-craters and nano-terraces on AA5052 sheet with enhanced water repellence and durable corrosion resistance are fabricated via low-cost subtractive manufacturing (SM) strategy. After fluoridation process, as-fabricated hierarchical structures possess highlighted self-cleaning and anti-adhesion capabilities. The following electrochemical test shows that the resultant surface effectively acts as a barrier against seawater infiltration suggesting superior anti-corrosion capacity. Meanwhile, the bacterial colony count test shows that the surface also possesses excellent resistance to microbiological adhesion. Such economic, efficient and environmental SM process is of great potential in fabricating multifunctional Al alloys with durable anti-corrosion, super-hydrophobic and bacteriostatic behaviors.