TY - JOUR A1 - Kunz, C. A1 - Bonse, Jörn A1 - Spaltmann, Dirk A1 - Neumann, C. A1 - Turchanin, A. A1 - Bartolomé, J. F. A1 - Müller, F. A. A1 - Gräf, S. T1 - Tribological performance of metal-reinforced ceramic composites selectively structured with femtosecond laser-induced periodic surface structures N2 - The impact of femtosecond (fs) laser-induced periodic surface structures (LIPSS) on tribological properties was investigated for metal-reinforced ceramic composites (Al2O3-ZrO2-Nb). For this purpose, the metallic niobium (Nb) phase was selectively structured with LIPSS in an air environment with different values of the fs-laser peak fluence by near-infrared fs-laser radiation (λ = 1025 nm, τ = 300 fs, frep = 1 kHz), taking advantage of the different light absorption behavior of ceramic and metal. The tribological performance was evaluated by reciprocating sliding tests in a ball-on-disc configuration using Ringer's solution as lubricant. The surfaces were characterized before and after laser irradiation by optical microscopy, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy and by measuring the contact angle with Ringer's solution. The LIPSS formation resulted in an increased wetting of the surface with the lubricant. Moreover, the selectively structured composite surfaces revealed a coefficient of friction significantly reduced by a factor of ~3 when compared to the non-irradiated surface. Furthermore, the formation of a laser-induced oxidation layer was detected with NbO as the most prominent oxidation state. Selectively structured composites with outstanding mechanical properties and enhanced tribological performance are of particular interest for biomedical applications. KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Ceramic matrix composites KW - Tribology PY - 2020 U6 - https://doi.org/10.1016/j.apsusc.2019.143917 SN - 0169-4332 SN - 1873-5584 VL - 499 IS - 1 SP - 143917 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-49255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Florian, Camilo A1 - Wonneberger, R. A1 - Undisz, A. A1 - Kirner, Sabrina V. A1 - Wasmuth, Karsten A1 - Spaltmann, Dirk A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Chemical effects during the formation of various types of femtosecond laser-generated surface structures on titanium alloy N2 - In this contribution, chemical, structural, and mechanical alterations in various types of femtosecond laser-generated surface structures, i.e., laser-induced periodic surface structures (LIPSS, ripples), Grooves, and Spikes on titanium alloy, are characterized by various surface analytical techniques, including X-ray diffraction and glow-discharge optical emission spectroscopy. The formation of oxide layers of the different laser-based structures inherently influences the friction and wear performance as demonstrated in oil-lubricated reciprocating sliding tribological tests (RSTTs) along with subsequent elemental mapping by energy-dispersive X-ray analysis. It is revealed that the fs-laser scan processing (790 nm, 30 fs, 1 kHz) of near-wavelength-sized LIPSS leads to the formation of a graded oxide layer extending a few hundreds of nanometers into depth, consisting mainly of amorphous oxides. Other superficial fs-laser-generated structures such as periodic Grooves and irregular Spikes produced at higher fluences and effective number of pulses per unit area present even thicker graded oxide layers that are also suitable for friction reduction and wear resistance. Ultimately, these femtosecond laser-induced nanostructured surface layers efficiently prevent a direct metal-to-metal contact in the RSTT and may act as an anchor layer for specific wear-reducing additives contained in the used engine oil. KW - Laser-induced oxide layer KW - Laser-induced periodic surface strctures (LIPSS) KW - Femtosecond laser processing KW - Tribology KW - Surface processing PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-505660 SN - 0947-8396 SN - 1432-0630 VL - 126 IS - 4 SP - 266 PB - Springer Nature Switzerland AG AN - OPUS4-50566 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Spaltmann, Dirk T1 - Editorial: Special issue "Laser-induced periodic surface nano- and microstructures for tribological applications" N2 - Laser material processing is an emerging technology that generates surface functionalities on the basis of optical, mechanical, or chemical properties. In the form of laser surface texturing (LST), it has attracted a remarkable amount of research to tailor surface properties towards various tribological applications. The main advantages of this single-step, laser-based technology are the contactless machining, featuring a high flexibility, efficiency, and speed, along with the excellent quality of the processed products. LST can be applied precisely localized to sub-micrometric areas, but, via laser beam scanning, it is also feasible for structuring large surface areas at the square meter size. This Special Issue focuses on the latest developments concerning the tribological performance of laser-generated periodic surface nano- and microstructures and their applications. This includes the laser-based processing of different surface patterns, such as “self-organized” laser-induced periodic surface structures (LIPSS, ripples), grooves, micro-spikes, hierarchical hybrid nano-/micro-structures, microfeatures generated by direct laser interference patterning (DLIP), or even dimples or other topographic geometries shaped by direct laser modification or ablation. The applications of these periodically nano- and micro-patterned surfaces may improve the lubricated or non-lubricated tribological performance of surfaces in conformal and even non-conformal contact through a reduction of wear, a variation of the coefficient of friction, altered load carrying capacity, etc., resulting in energy saving, improved reliability, increased lifetimes as well as durability, leading in turn to extended maintenance intervals/reduced down-time. This can be beneficial in terms of bearings, gears, engines, seals, cutting tools, or other tribological components. Fundamental aspects addressed may involve the investigation of the relevant physical and chemical effects accompanying the laser-generated nano- and microscale topographies, such as alterations of the material structures, the hardness, superficial oxidation, the role of additives contained in lubricants, surface wettability, micro-hydrodynamic effects, etc. For this Special Issue we aim to attract both academic and industrial researchers and would like to provide a bridge between research in the fields of tribology and laser material processing in order to foster the current knowledge and present new ideas for future applications and new technologies. KW - Laser-induced periodic surface structures (LIPSS) KW - Tribology KW - Applications KW - Wear KW - Friction PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-505948 SN - 2075-4442 VL - 8 IS - 3 SP - 34, 1 EP - 34, 3 PB - MDPI CY - Basel AN - OPUS4-50594 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Kirner, Sabrina V. A1 - Epperlein, Nadja A1 - Spaltmann, Dirk A1 - Krüger, Jörg T1 - Surface functionalization by laser-induced periodic surface structures (LIPSS) N2 - In this contribution the mechanisms of formation and current applications of LIPSS are reviewed, including the colorization of technical surfaces, the control of surface wetting properties, the mimicry of the natural texture of animal integuments, the tailoring of surface colonization by bacterial biofilms, and the improvement of the tribological performance of nanostructured metal surfaces. T2 - 10th Stuttgart Laser Technology Forum 2018 CY - Stuttgart, Germany DA - 05.06.2018 KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Surface functionalization KW - Wetting KW - Tribology KW - Biofilms PY - 2018 SP - 35 AN - OPUS4-45128 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Kirner, Sabrina V. A1 - Wirth, Thomas A1 - Florian, Camilo A1 - Sturm, Heinz A1 - Spaltmann, Dirk A1 - Krüger, Jörg T1 - Chemical effects during the formation of femtosecond laser-induced periodic surface structures N2 - The processing of laser-induced periodic surface structures (LIPSS, ripples) on metals and semiconductors in ambient air is usually accompanied by superficial oxidation effects – a fact that is widely neglected in the current literature. In this contribution, chemical, structural, and mechanical alterations in the formation of femtosecond LIPSS are characterized by a variety of surface analytical techniques, including energy dispersive X-ray analyses (EDX), X-ray photoelectron spectroscopy (XPS), micro Raman spectroscopy (µ-RS), and depth-profiling Auger electron microscopy (AEM). Alternative routes of electrochemical and thermal oxidation allow to qualify the relevance of superficial oxidation effects on the tribological performance in oil lubricated reciprocating sliding tribological tests (RSTT). It is revealed that the fs-laser processing of near-wavelength sized LIPSS on metals leads to the formation of a few hundreds of nanometers thick graded oxide layers, consisting mainly of amorphous oxides. Regardless of reduced hardness and limited thickness, this nanostructured surface layer efficiently prevents a direct metal-to-metal contact in the RSTT and may also act as an anchor layer for specific wear-reducing additives contained in the used engine oil. T2 - EMRS Spring Meeting 2019, Symposium V “Laser interactions with materials: from fundamentals to applications" CY - Nice, France DA - 27.05.2019 KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser KW - Oxidation KW - Tribology PY - 2019 AN - OPUS4-48127 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Kirner, Sabrina V. A1 - Wirth, Thomas A1 - Spaltmann, Dirk A1 - Krüger, Jörg T1 - Chemical effects in the formation of fs-laser-induced periodic surface structures N2 - The processing of laser-induced periodic surface structures (LIPSS, ripples) on metals and semiconductors in ambient air is usually accompanied by superficial oxidation effects - widely neglected in the current literature. In this contribution, chemical, structural, and mechanical alterations in the formation of femtosecond LIPSS are characterized by a variety of surface analytical techniques, including energy dispersive X-ray analyses (EDX), X-ray photoelectron spectroscopy (XPS), micro Raman spectroscopy (µ-RS), and depth-profiling Auger electron microscopy (AEM). Alternative routes of electrochemical and thermal oxidation allow to qualify the relevance of superficial oxidation effects on the tribological performance in oil lubricated reciprocating sliding tribological tests (RSTT). It is revealed that the fs-laser processing of near-wavelength sized LIPSS on metals leads to the formation of a few hundreds of nanometer thick graded oxide layer, consisting mainly of amorphous oxides. Regardless of its reduced hardness and limited thickness, this nanostructured surface layer can effciently prevent a direct metal-metal contact in the RSTT and may also act as an anchor layer for specific wear-reducing additives contained in the engine oil involved T2 - 8th International LIPSS Workshop CY - Bochum, Germany DA - 27.09.2018 KW - Laser-induced periodic surface structures, LIPSS KW - Femtosecond KW - Oxidation KW - Tribology PY - 2018 AN - OPUS4-46106 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -