TY - JOUR A1 - Tsibidis, G. D. A1 - Mimidis, A. A1 - Skoulas, E. A1 - Kirner, Sabrina V. A1 - Krüger, Jörg A1 - Bonse, Jörn A1 - Stratakis, E. T1 - Modelling periodic structure formation on 100Cr6 steel after irradiation with femtosecond-pulsed laser beams N2 - We investigate the periodic structure formation upon intense femtosecond pulsed irradiation of chrome steel (100Cr6) for linearly polarised laser beams. The underlying physical mechanism of the laser-induced periodic structures is explored, their spatial frequency is calculated and theoretical results are compared with experimental observations. The proposed theoretical model comprises estimations of electron excitation, heat transfer, relaxation processes, and hydrodynamics-related mass transport. Simulations describe the sequential formation of sub-wavelength ripples and supra-wavelength grooves. In addition, the influence of the laser wavelength on the periodicity of the structures is discussed. The proposed theoretical investigation offers a systematic methodology towards laser processing of steel surfaces with important applications. KW - Laser-induced periodic surface structures KW - Femtosecond laser ablation KW - Steel PY - 2018 UR - https://link.springer.com/article/10.1007/s00339-017-1443-y U6 - https://doi.org/10.1007/s00339-017-1443-y SN - 0947-8396 SN - 1432-0630 VL - 124 IS - 1 SP - 27, 1 EP - 13 PB - Springer-Verlag AN - OPUS4-43626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Porta-Velilla, L. A1 - Martínez, E. A1 - Frechilla, A. A1 - Castro, M. A1 - de la Fuente, G. F. A1 - Bonse, Jörn A1 - Angurel, L. A. T1 - Grain orientation, angle of incidence, and beam polarization effects on ultraviolet 300 ps-laser-induced nanostructures on 316L stainless steel N2 - Laser-induced periodic surface structures (LIPSS) represent a unique route for functionalizing materials through the fabrication of surface nanostructures. Commercial AISI 316L stainless steel (SS316L) surfaces are laser treated by ultraviolet 300 ps laser pulses in a laser line scanning (LLS) approach. Processing parameters are optimized (pulse energy of 2.08 µJ, pulse repetition frequency of 300 kHz, and suitable laser scan and sample displacement rates) for the generation of low spatial frequency LIPSS over a large 25 × 25 mm2 area. Different angles of incidence of the laser radiation (0°, 30°, and 45°) and different linear laser beam polarizations (s and p) produce a plethora of rippled surface morphologies at distinct grains. Scanning electron microscopy and 2D Fourier transforms, together with calculations of the optical energy deposited at the treated surfaces using Sipe's first-principles electromagnetic scattering theory, are used to study and analyze in detail these surface morphologies. Combined with electron backscattering diffraction, analyses allow associating site-selectively various laser-induced-surface morphologies with the underlying crystalline grain orientation. Resulting grain orientation maps reveal a strong impact of the grain crystallographic orientation on LIPSS formation and point toward possible strategies, like multi-step processes, for improving the manufacturing of LIPSS and their areal coverage of polycrystalline technical materials. KW - Laser-induced periodic surface structures (LIPSS) KW - Steel KW - Grain orientation KW - Electron backscattering diffraction (EBSD) KW - Laser processing PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-588929 SN - 1863-8899 SP - 1 EP - 21 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-58892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -