Effect of crystal structure on fabrication of fine periodic surface structures with short pulsed laser

In recent years, nanostructures have been required for industry and medical services, to perform functions such as reduction in friction, control of wetta-bility, and enhancement in biological affinity. Ultrashort pulsed lasers have been applied to meet these demands, and have been actively studied both experimentally and theoretically in terms of phenomena and principles. In this study, to clarify the phenomenon of the fabrication of laser-induced periodic surface structures (LIPSS), and its application to industry, experiments were conducted on SUS304, titanium, and nickel-phosphorus by a short pulsed laser that has a longer pulse duration, higher cost-effectiveness, and higher stability than ultrashort pulsed lasers. The results confirmed that while LIPSS were fabricated on Ti and Ni-P workpieces, a uniform fine periodic structure was not fabricated on the whole irradiated surface of SUS304, and crystal grain boundaries appeared with low energy density and irradiation number because SUS304 is an alloy composed of Fe, Cr, and Ni. Further, the short pulsed laser has a low power and long pulse duration, inducing the thermal effect. We clarified the effect of crystal structure on fabricating fine periodic surface structures with short pulsed laser.