Study on Preparation of Superhydrophobic Surface by Selective Laser Melting and Corrosion Resistance  
Lei Xing  
School of Mechanical and Electronic Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China; [EMAIL_ADDRESS] (J.Y.); [EMAIL_ADDRESS] (Z.J.); [EMAIL_ADDRESS] (X.H.); [EMAIL_ADDRESS] (C.D.)  
[PERSON]  
Correspondence: [EMAIL_ADDRESS] (L.X.); [EMAIL_ADDRESS] (Q.Z.)  
Zhiyong Ji  
School of Mechanical and Electronic Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China; [EMAIL_ADDRESS] (J.Y.); [EMAIL_ADDRESS] (Z.J.); [EMAIL_ADDRESS] (X.H.); [EMAIL_ADDRESS] (C.D.)  
Xingjiu Huang  
School of Mechanical and Electronic Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China; [EMAIL_ADDRESS] (J.Y.); [EMAIL_ADDRESS] (Z.J.); [EMAIL_ADDRESS] (X.H.); [EMAIL_ADDRESS] (C.D.)  
[PERSON]
acid to etch micro-pores on the surface microstructure, so that the sample surface had superhydrophobic performance [23]. [PERSON] et al. used the sol-gel method to obtain silica sol doped with different amounts of copper nanoparticles, and then dipped it on a cotton fabric substrate, dried and solidified, and finally used Hexadecyl Trimethoxysilane (HDTMS) modified to obtain a superhydrophobic surface with self-cleaning and antibacterial properties [24]. The rise of laser processing technology has enriched the processing methods of superhydrophobic surfaces. [PERSON] et al.'s study based on the microscopic morphology of the fish body and the arrangement of the scales. Under the action of the laser beams, by controlling the density of the laser path and processing time, biomimetic fish-scale surfaces with an inclined surface was obtained on the aluminum surface. The wettability results showed that the sample with 100% zoom ratio demonstrated excellent superhydrophobicity [25].  
Selective Laser Melting (SLM) 3D-printed technology is one of the laser processing methods; its equipment adopts multi-beam printing, and the printing accuracy is at the micron level, so it has the advantages of high efficiency, good printing accuracy and a controllable shape, which is suitable for surface topography processing [26; 27]. This paper introduces Selective Laser Melting (SLM) 3D-printed technology into the preparation of superhydrophobic surfaces. In the early stages, the minimum size of the cylindrical structure prepared by the printer was roughly determined according to the printed accuracy and experimental exploration: the diameter of the cylinder \(d\geq~{}150~{}\upmu\)m, cylindrical clearance \(s-d\geq~{}100~{}\upmu\)m, where \(s\) is the center distance between adjacent cylinders, the height of the cylinder \(H\geq~{}10~{}\upmu\)m. Tests show that when the cylinder diameter \(d\) is 180 \(\upmu\)m, the adjacent cylinder gap \(s-d\) is 280 \(\upmu\)m, and the cylinder height \(H\) is 400 \(\upmu\)m, the contact angle of the 3D-printed + modified sample is 153.4\({}^{\circ}\). It meets the superhydrophobic conditions and has good superhydrophobicity. The aim of the work is to innovatively use 3D printing to prepare superhydrophobic surfaces, compare the effects of different post-treatment methods and time on corrosion resistance, and reveal the root cause of the surface transition from hydrophilic to superhydrophobic.