Tailoring metallic surface properties induced by laser surface processing for industrial applications

As a simple, reproducible, and pollution-free technique with the potential of integration and automation, laser processing has attracted increasing attention. Laser processing, which includes laser polishing, laser cleaning, and fabrication of laser-induced micro-/nano-structures, has been demonstrated to yield smooth, clean, func- tional surfaces and effective joining. Laser polishing is an advanced, highly efficient, and ecofriendly polishing technology. This study demonstrated the laser polishing of a selective laser-melted Inconel 718 (IN718) superal- loy and a titanium alloy sample. The surface roughnesses R_a and R_z of the IN718 superalloy were respectively re- duced from 8 and 33 μm to 0.2 and 0.8 μm, and the R_a of the titanium alloy was reduced from 9.8 μm to 0.2 μm. Moreover, the wear resistance and corrosion resistance of the IN718 were apparently improved. As another surface-related processing method, laser cleaning was used to clean terminal blocks. Almost all the contaminants were removed, as verified by the absence of their chemical compositions and the decreased surface roughness. In addition, a superhydrophobic surface with a contact angle of over 160° and sliding angle of b8° on stainless steel was obtained by laser texturing treatment. These results demonstrate the high potential of laser processing in the scientific, technological, and industrial fields.