Long-term seawater anti-corrosion properties of Al alloy triggered by femtosecond laser structuring with phase change

Abstract

Through adopting a technique of femtosecond laser micro/nano-structuring, we successfully modify the surface of aluminium alloy material into the long-term stable anti-corrosive properties, exhibiting the measured corrosion rate two orders of magnitude smaller than that of the bare sample. The underlying mechanisms are attributed to both the surface micro/nano-structure formation with the thick stable oxide layers and the significant phase change from crystalline to amorphous by the laser-induced stress and compressive strain, which consequently reduce the free energy and chemical activity of the structured surface. Such investigations may open a new eco-friendly way to produce anti-corrosive metal surfaces for deep seawater applications.