Laser-Enhanced Surface Structurization of Titanium and Its Alloys

The laser treatment is increasingly often applied to modify the surface of titanium and its alloys. As shown in this chapter, the applied methods include direct laser ablation, direct laser interference patterning, laser interference lithography, laser-induced periodic surface structuring, the femtosecond laser nanotexturing method, laser shock peening, laser cladding, pulsed laser deposition, laser surface remelting, laser polishing, and selective laser melting. The laser surface structurization increases the roughness with a benefit for biocompatibility, but excessive tensile cracks can appear. The laser irradiation may have a highly differentiating effect on wettability, resulting in surfaces changed from superhydrophobic to superhydrophilic. This treatment can also be positive for bioactivity, as shown by protein uptake and osseointegration, and cell attachment and growth, but the properties of the laser (type, wavelength, and time of radiation) might affect the cell proliferation or at least the cell spreading. The laser surface modification is assumed to have potential for improving the antibacterial performance of titanium implants. The corrosion resistance can also be slightly improved by the change in the passive layer. The laser surface modification can substantially and positively affect hardness, fatigue, and wear resistance. The laser treatment can also be useful for texturing of surfaces, followed by deposition of coatings, for laser-based deposition of coatings, including laser cladding, and deposition of coatings with the next laser treatment of the coating.