TY - CONF A1 - Krüger, Jörg A1 - Symietz, Christian A1 - Gildenhaar, Renate A1 - Berger, Georg T1 - Covering Ti6Al4V implant material with bioactive ceramics using femtosecond laser processing T2 - 5th European Conference on Applications of Femtosecond Lasers in Materials Science (FemtoMat 2013) CY - Mauterndorf, Austria DA - 2013-03-18 PY - 2013 AN - OPUS4-28048 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Pentzien, Simone A1 - Koter, Robert T1 - Cleaning of soiled paper model samples using short and ultrashort laser pulses T2 - Konferenz "New Approaches to Book and Paper Conservation-Restoration" CY - Horn, Austria DA - 2011-05-09 PY - 2011 AN - OPUS4-21839 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pentzien, Simone A1 - Conradi, Andrea A1 - Koter, Robert A1 - Krüger, Jörg ED - Engel, P. ED - Schirò, J. ED - Larsen, R. ED - Moussakova, E. ED - Kecskeméti, I. T1 - Cleaning of soiled paper model samples using short and ultrashort laser pulses N2 - Paper is one of the most important materials representing and witnessing human culture particularly as a carrier medium for text and image. As soiling hampers the reception of information, paper cleaning techniques are needed. Traditional mechanical and chemical cleaning methods are used by conservator-restorers. In some cases, a classical cleaning procedure of paper objects yields unsatisfactory results or a conventional treatment is even impossible. Especially, fragile paper objects cause problems due to mechanical instabilities. Laser cleaning as a non-contact method might be a way to overcome some of the limitations of classical cleaning techniques. Laser parameters have to be chosen to achieve removal of the soiling without influencing the artwork. Any immediate as well as long-term effects causing an irreversible change of the artwork have to be avoided. At present, most laser applications are found in stone and metal conservation, while laser treatment of complex organic materials like paper is still not fully developed for application in conservators' workshops. This contribution describes recent work of pulsed laser cleaning of soiled model samples. Pure cellulose, rag paper and wood-pulp paper were mechanically soiled with pulverized charcoal in a standardized procedure to make model samples representing essential characteristics of contaminated real-world artworks. Afterwards, model samples were cleaned using short and ultrashort laser pulses in the nanosecond and femtosecond time domain, respectively. An extensive analysis of the model samples after laser treatment using an optical microscope and a multi-spectral imaging system allows a comparison of the cleaning results obtained with both laser sources. T2 - Conference 'New Approaches to Book and Paper Conservation - Restoration' CY - Horn, Austria DA - 09.05.2011 KW - Laser cleaning KW - Ablation KW - Laser impact on surfaces KW - Paper KW - Femtosecond laser KW - Nanosecond laser PY - 2011 SN - 978-3-85028-518-6 SP - 519 EP - 532 PB - Verlag Berger, Horn CY - Vienna, Austria AN - OPUS4-23705 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kotsifaki, D.G. A1 - Zekou, L. A1 - Pentzien, Simone A1 - Krüger, Jörg A1 - Serafetinides, A.A. ED - Saunders, D. ED - Strlic, M. ED - Korenberg, C. ED - Luxford, N. ED - Birkhölzer, K. T1 - Cleaning of artificially soiled papers by infrared and mid-infrared lasers N2 - One of the most important materials presenting and witnessing human culture is paper. The cleaning of paper is often necessary because contamination must be removed so that the fragile organic substrate can be preserved. The conventional cleaning methods are mechanical or involve the application of chemicals. These methods can damage drawings or print layers to some extent or make the original paper substrate brittle. More specifically, the use of a scalpel blade can cause damage to fibers. Chemical cleaning is difficult to perform locally, can dissolve foreign matter that then migrates into the paper substrate, or involves volatile organic compounds that can be harmful to the conservator. There is, therefore, a need for new conservation technologies aimed at the safe cleaning of paper. Lasers have proved to be an appropriate tool for cleaning as the energy dose and penetration depth at the specific point of contamination can be controlled. Additionally, if used properly, laser cleaning is not destructive to the paper. T2 - LACONA IX - Lasers in the conservation of artworks CY - London, UK DA - 07.09.2011 KW - Laser cleaning KW - Paper KW - Artificial soiling KW - Nanosecond laser KW - Microsecond laser PY - 2013 SN - 978-1-904982-87-6 SP - 219 EP - 221 PB - Archetype publications Ltd. AN - OPUS4-27956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Pentzien, Simone A1 - Conradi, Andrea T1 - Cleaning of artificially soiled paper with 532-nm nanosecond laser radiation T2 - EMRS 2007 Spring Meeting, Symposium S: Science & Technology of Cultural heritage Materials : Art conservation and Restoration CY - Strasbourg, France DA - 2007-05-28 PY - 2007 AN - OPUS4-14763 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Pentzien, Simone A1 - Conradi, Andrea T1 - Cleaning of artificially soiled paper with 532-nm nanosecond laser radiation N2 - Cleaning of paper is a challenging task due to the fact that a contamination should be removed and a fragile organic original material has to be preserved. Pulsed laser cleaning of artificially soiled Whatman© filter paper samples serving as models for historical paper was performed. Different cleaning strategies employing 8-ns laser pulses at 532 nm wavelength were applied to clean paper avoiding undesired effects like discoloration (yellowing) and mechanical deterioration of the substrate. Multi shot experiments with low-energy pulses were compared with single pulse investigations utilizing high pulse energies achieving a constant energy load incident on the samples in both cases. The cleaning efficiency and possible yellowing effects were evaluated by means of a multi spectral imaging system. An extensive microscopic analysis of the cleaned parts of the samples provided insight into the remaining soiling on the surface and in the bulk of the paper material after laser treatment. As a reference, a hard and a soft eraser were used to clean the samples. KW - Laser cleaning KW - Paper KW - Colorimetry PY - 2008 DO - https://doi.org/10.1007/s00339-008-4476-4 SN - 0947-8396 VL - 92 IS - 1 SP - 179 EP - 183 PB - Springer CY - Berlin AN - OPUS4-17331 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pentzien, Simone A1 - Conradi, Andrea A1 - Koter, Robert A1 - Krüger, Jörg T1 - Cleaning of artificially soiled paper using nanosecond, picosecond and femtosecond laser pulses N2 - Cleaning of cultural assets, especially fragile organic materials like paper, is a part of the conservation process. Laser radiation as a non-contact tool offers prospects for that purpose. For the studies presented here, paper model samples were prepared using three different paper types (pure cellulose, rag paper, and wood-pulp paper). Pure cellulose serves as reference material. Rag and woodpulp paper represent essential characteristics of the basic materials of real-world artworks. The papers were mechanically soiled employing pulverized charcoal. Pure and artificially soiled paper samples were treated with laser pulses of 28 fs (800 nm wavelength) and 8–12 ns (532 nm) duration in a multi pulse approach. Additionally, the cellulose reference material was processed with 30 ps (532 nm) laser pulses. Damage and cleaning thresholds of pure and soiled paper were determined for the different laser regimes. Laser working ranges allowing for removal of contamination and avoiding permanent modification to the substrate were found. The specimens prior and after laser illumination were characterized by light-optical microscopy (OM) and scanning electron microscopy (SEM) as well as multi spectral imaging analysis. The work extends previous nanosecond laser cleaning investigations on paper into the ultra-short pulse duration domain. KW - Laser cleaning KW - Ablation KW - Laser impact on surfaces KW - Paper KW - Femtosecond laser PY - 2010 DO - https://doi.org/10.1007/s00339-010-5809-7 SN - 0947-8396 VL - 101 IS - 2 SP - 441 EP - 446 PB - Springer CY - Berlin AN - OPUS4-22155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Pentzien, Simone A1 - Conradi, Andrea T1 - Cleaning of artifically soled paper using nanosecond, picosecond and femtosecond laser pulses T2 - Konferenz COLA 09 (10th International Conference on Laser Ablation) CY - Singapore DA - 2009-11-22 PY - 2009 AN - OPUS4-19762 LA - deu 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 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505660 DO - https://doi.org/10.1007/s00339-020-3434-7 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 - Müller, Kai A1 - Mirabella, Francesca A1 - Knigge, Xenia A1 - Mezera, Marek A1 - Weise, Matthias A1 - Sahre, Mario A1 - Wasmuth, Karsten A1 - Voss, Heike A1 - Hertwig, Andreas A1 - Krüger, Jörg A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Bonse, Jörn T1 - Chemical and topographical changes upon sub-100-nm laser-induced periodic surface structure formation on titanium alloy: the influence of laser pulse repetition rate and number of over-scans N2 - Titanium and its alloys are known to allow the straightforward laser-based manufacturing of ordered surface nanostructures, so-called high spatial frequency laser-induced periodic surface structures (HSFL). These structures exhibit sub-100 nm spatial periods – far below the optical diffraction limit. The resulting surface functionalities are usually enabled by both, topographic and chemical alterations of the nanostructured surfaces. For exploring these effects, multi-method characterizations were performed here for HSFL processed on Ti–6Al–4V alloy upon irradiation with near-infrared ps-laser pulses (1030 nm, ≈1 ps pulse duration, 1–400 kHz) under different laser scan processing conditions, i.e., by systematically varying the pulse repetition frequency and the number of laser irradiation passes. The sample characterization involved morphological and topographical investigations by scanning electron microscopy (SEM), atomic force microscopy (AFM), tactile stylus profilometry, as well as near-surface chemical analyses hard X-ray photoelectron spectroscopy (HAXPES) and depth-profiling time-of-flight secondary ion mass spectrometry (ToF-SIMS). This provides a quantification of the laser ablation depth, the geometrical HSFL characteristics and enables new insights into the depth extent and the nature of the non-ablative laser-induced near-surface oxidation accompanying these nanostructures. This allows to answer the questions how the processing of HSFL can be industrially scaled up, and whether the latter is limited by heat-accumulation effects. T2 - 2023 E-MRS Spring Meeting, Symposium L "Making light matter: lasers in material sciences and photonics" CY - Strasbourg, France DA - 29.05.2023 KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser pulses KW - Laser processing KW - Hard X-ray photoelectron spectroscopy (HAXPES) KW - Time-of-flight secondary ion mass spectrometry (ToF-SIMS) PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589902 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/pssa.202300719 DO - https://doi.org/10.1002/pssa.202300719 SN - 1862-6319 VL - 220 SP - 1 EP - 12 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-58990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -