Construction of superhydrophobic surfaces with different water adhesion on the low-temperature steels by picosecond laser processing

Manufacturing superhydrophobic metallic surfaces with desired water adhesion for intended applications such as anti-icing and microdroplets transportation remains a grand challenge. Herein, we demonstrated the fabrication of the superhydrophobic surfaces with different water adhesion on the low-temperature steels including DH36, EH40 and FH36 steels via combined strategies of picosecond laser processing and room-temperature vacuum processing. The laser processing could regulate the dimension of the micro/nanostructures on the low-temperature steel surfaces and the vacuum processing controlled the surface chemical compositions of the laser-processed surfaces, leading to the transition of wetting behaviors from the superhydrophilic states, then to the superhydrophobic Wenzel's states with strong water adhesion and finally to the superhydrophobic Cassie-Baxter's states with weak water adhesion. The superhydrophobic surfaces with the Wenzel's states showed great potential in non-destructive and selective transportation of water droplets, while those with the Cassie-Baxter's states exhibited promising anti-icing performance as well as desirable corrosion, impact, and erosion resistance. This work provides an effective, pollution-free, and stable route for controlling the superwettability of the low-temperature steel surfaces and could find promising applications in surface modifications of metals and alloys.