TY - JOUR A1 - Pirker, F. A1 - Toth, I. A1 - Cihak-Bayr, U. A1 - Grundtner, R. A1 - Vernes, A. A1 - Benedicto, J. A1 - Spaltmann, Dirk A1 - Gradt, Thomas A1 - Alberdi, A. A1 - Alonso, I. A1 - Bayón, R. A1 - Igartua, A. A1 - García, Á. A1 - Pagano, F. A1 - Bravo, I. A1 - Kogia, M. A1 - Dykeman, D. A1 - Liedtke, S. A1 - Minami, I. A1 - Nyberg, E. A1 - Soivio, K. A1 - Ronkainen, H. A1 - Majaniemi, S. A1 - Heino, V. A1 - Gkagkas, K. A1 - Mont, L. A1 - Amigorena, I. T1 - Tribological characterisation services for materials - i-TRIBOMAT N2 - Um den Entwicklungsprozess von neuen Komponenten zu beschleunigen, ist die Vorrausage der Eigenschaften der eingesetzten Werkstoffe im Betrieb der Komponenten von enormer Bedeutung. Um neue Werkstoffe hinsichtlich Ihrer Performance (in einer Komponente) bewerten zu können, ist deshalb die Entwicklung neuer innovativer Methoden notwendig. Diese Methoden können auch unter dem Begriff „lab-to-field“ oder „materials“ – up-scaling zusammengefasst werden. D. h. Werkstoffe werden im Labor charakterisiert, und deren Eigenschaften mittels z.B. Simulation auf die Komponentenperformance hochskaliert (upscaling). i-TRIBOMAT ist ein EU gefördertes Projekt (H2020, GA Nr. 814494) mit dem Ziel ein Open Innovation Test Bed für tribologische Werkstoffcharakterisierung aufzubauen und entsprechende Services von der tribologischen Charakterisierung neuer Werkstoffe bis hin zu Simulationsmodellen zur Vorrausage der Perfomance von Komponenten der Industrie anzubieten. Durch die Bündelung von Knowhow und Infrastruktur zu Charakterisierung sowie den Aufbau einer digitalen Plattform, wird i-TRIBOMAT das weltgrößte Open Innovation Test Bed für tribologische Werkstoffcharakterisierung. N2 - The prediction of the properties of the materials used in the operation of components is of enormous importance, in order to accelerate the development process of new components. To evaluate new materials in terms of their performance (in a component), the development of new innovative methods is necessary. These methods can also be summarized under the term lab-to-field or materials – upscaling, meaning materials being characterised in a laboratory and their properties being upscaled to the component performance by means of e.g. simulation. i-TRIBOMAT is a EU funded project (H2020, GA Nr. 814494) aiming at building an Open Innovation Test Bed for tribological material characterization and offering corresponding services from tribological characterization of new materials to simulation models for predicting the performance of industrial components. By bundling the infrastructure, know-how for characterization and building a digital platform, i-TRIBOMAT becomes the world’s largest open innovation test bed for tribological material characterization. T2 - 22nd International Colloquium Tribology CY - Esslingen, Germany DA - 28.01.2020 KW - Tribologie KW - Lab-to-field up-scaling KW - Werkstoffdatenbank KW - Geteilte Infrastruktur KW - Tribo-Analytik KW - Intelligente tribologische Werkstoffcharakterisierung KW - Lab-to-field upscaling KW - Tribology KW - Intelligent tribological material characterization KW - Materials database KW - Shared infrastruture KW - Tribo-analytics PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576762 DO - https://doi.org/10.30419/TuS-2020-0026 SN - 0724-3472 SN - 2941-0908 VL - 67 IS - 5-6 SP - 35 EP - 50 PB - Expert CY - Tübingen AN - OPUS4-57676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reed, B. P. A1 - Cant, D.J.H. A1 - Spencer, J. A1 - Carmona-Carmona, A. J. A1 - Bushell, A. A1 - Herrara-Gómez, A. A1 - Kurokawa, A. A1 - Thissen, A. A1 - Thomas, A.G. A1 - Britton, A.J. A1 - Bernasik, A. A1 - Fuchs, A. A1 - Baddorf, A. P. A1 - Bock, B. A1 - Thellacker, B. A1 - Cheng, B. A1 - Castner, D.G. A1 - Morgan, D.J. A1 - Valley, D. A1 - Willneff, E.A. A1 - Smith, E.F. A1 - Nolot, E. A1 - Xie, F. A1 - Zorn, G. A1 - Smith, G.C. A1 - Yasukufu, H. A1 - Fenton, J. L. A1 - Chen, J. A1 - Counsell, J..D.P. A1 - Radnik, Jörg A1 - Gaskell, K.J. A1 - Artyushkova, K. A1 - Yang, L. A1 - Zhang, L. A1 - Eguchi, M. A1 - Walker, M. A1 - Hajdyla, M. A1 - Marzec, M.M. A1 - Linford, M.R. A1 - Kubota, N. A1 - Cartazar-Martínez, O. A1 - Dietrich, P. A1 - Satoh, R. A1 - Schroeder, S.L.M. A1 - Avval, T.G. A1 - Nagatomi, T. A1 - Fernandez, V. A1 - Lake, W. A1 - Azuma, Y. A1 - Yoshikawa, Y. A1 - Shard, A.G. T1 - Versailles Project on Advanced Materials and Standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene N2 - We report the results of a Versailles Project on Advanced Materials and Standards interlaboratory study on the intensity scale calibration of x-ray photoelectron spectrometers using low-density polyethylene (LDPE) as an alternative material to gold, silver, and copper. An improved set of LDPE reference spectra, corrected for different instrument geometries using a quartz-monochromated Al Kα x-ray source, was developed using data provided by participants in this study. Using these new reference spectra, a transmission function was calculated for each dataset that participants provided. When compared to a similar calibration procedure using the NPL reference spectra for gold, the LDPE intensity calibration method achieves an absolute offset of ∼3.0% and a systematic deviation of ±6.5% on average across all participants. For spectra recorded at high pass energies (≥90 eV), values of absolute offset and systematic deviation are ∼5.8% and ±5.7%, respectively, whereas for spectra collected at lower pass energies (<90 eV), values of absolute offset and systematic deviation are ∼4.9% and ±8.8%, respectively; low pass energy spectra perform worse than the global average, in terms of systematic deviations, due to diminished count rates and signal-to-noise ratio. Differences in absolute offset are attributed to the surface roughness of the LDPE induced by sample preparation. We further assess the usability of LDPE as a secondary reference material and comment on its performance in the presence of issues such as variable dark noise, x-ray warm up times, inaccuracy at low count rates, and underlying spectrometer problems. In response to participant feedback and the results of the study, we provide an updated LDPE intensity calibration protocol to address the issues highlighted in the interlaboratory study. We also comment on the lack of implementation of a consistent and traceable intensity calibration method across the community of x-ray photoelectron spectroscopy (XPS) users and, therefore, propose a route to achieving this with the assistance of instrument manufacturers, metrology laboratories, and experts leading to an international standard for XPS intensity scale calibration. KW - X-ray photoelectron spectroscopy KW - Transmission function KW - Intensity scale calibration KW - Reference spectra KW - Low-density polyethylene (LDPE) PY - 2020 DO - https://doi.org/10.1116/6.0000577 VL - 38 IS - 6 SP - 063208 AN - OPUS4-51655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reed, B. P. A1 - Cant, D.J.H. A1 - Spencer, S.J. A1 - Carmona-Carmona, A. J. A1 - Bushell, A. A1 - Herrara-Gómez, A. A1 - Kurokawa, A. A1 - Thissen, A. A1 - Thomas, A.G. A1 - Britton, A.J. A1 - Bernasik, A. A1 - Fuchs, A. A1 - Baddorf, A.P. A1 - Bock, B. A1 - Thellacker, B. A1 - Cheng, B. A1 - Castner, D.G. A1 - Morgan, D.J. A1 - Valley, D. A1 - Willneff, E.A. A1 - Smith, E.P. A1 - Nolot, E. A1 - Xie, F. A1 - Zorn, G. A1 - Smith, G.C. A1 - Yasukufu, H. A1 - Fenton, J.L. A1 - Chen, J. A1 - Counsell, J.D.P. A1 - Radnik, Jörg A1 - Gaskell, K.J. A1 - Artyushkova, K. A1 - Yang, L. A1 - Zhang, L. A1 - Eguchi, M. A1 - Walker, M. A1 - Hajdyla, M. A1 - Marzec, M.M. A1 - Linford, M.R. A1 - Kubota, N. A1 - Cortazar-Martinez, O. A1 - Dietrich, P. A1 - Satoh, R. A1 - Schroeder, S.L.M. A1 - Avval, T.G. A1 - Nagatomi, T. A1 - Fernandez, V. A1 - Lake, W. A1 - Azuma, Y. A1 - Yoshikawa, Y. A1 - Compean-Gonzalez, C.L. A1 - Ceccone, G. A1 - Shard, A.G. T1 - ERRATUM: “Versailles project on advanced materials and standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene” [J. Vac. Sci. Technol. A 38, 063208 (2020)] N2 - The lead authors failed to name two collaborators as co-authors. The authors listed should include: Miss Claudia L. Compean-Gonzalez (ORCID: 0000-0002-2367-8450) and Dr. Giacomo Ceccone (ORCID: 0000-0003-4637-0771). These co-authors participated in VAMAS project A27, provided data that were analyzed and presented in this publication (and supporting information), and reviewed the manuscript before submission. KW - X-ray photoelectron spectroscopy KW - Transmission function KW - Low-density polyethylene PY - 2021 DO - https://doi.org/10.1116/6.0000907 VL - 39 IS - 2 SP - 027001 PB - American Vacuum Society AN - OPUS4-52380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K. J. A1 - Kim, A. S. A1 - Jang, J. S. A1 - Suh, J. K. A1 - Wirth, Thomas A1 - Hodoroaba, Vasile-Dan A1 - Unger, Wolfgang A1 - Araujo, J. R. A1 - Archanjo, B. S. A1 - Galhardo, C. E. A1 - Damasceno, J. A1 - Achete, C. A. A1 - Wang, H. A1 - Wang, M. A1 - Bennett, J. A1 - Simons, D. A1 - Kurokawa, A. A1 - Terauchi, S. A1 - Fujimoto, T. A1 - Streeck, C. A1 - Beckhoff, B. A1 - Spencer, S. A1 - Shard, A. T1 - Measurement of mole fractions of Cu, In, Ga and Se in Cu(In,Ga)Se2 films N2 - CCQM key comparison K-129 for the quantitative analysis of Cu(In,Ga)Se2 (CIGS) films has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The objective of this key comparison is to compare the equivalency of the National Metrology Institutes (NMIs) and Designated Institutes (DIs) for the measurement of mole fractions of Cu, In, Ga and Se in a thin CIGS film. The measurand of this key comparison is the average mole fractions of Cu, In, Ga and Se of a test CIGS alloy film in the unit of mole fraction (mol/mol). Mole fraction with the metrological unit of mol/mol can be practically converted to atomic fraction with the unit of at%. In this key comparison, a CIGS film with certified mole fractions was supplied as a reference specimen to determine the relative sensitivity factors (RSFs) of Cu, In, Ga and Se. The mole fractions of the reference specimen were certified by isotope dilution - inductively coupled plasma/mass spectrometry (ID-ICP/MS) and are traceable to the SI. A total number counting (TNC) method was recommended as a method to determine the signal intensities of the constituent elements acquired in the depth profiles by Secondary Ion Mass Spectrometry (SIMS), X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). Seven NMIs and one DI participated in this key comparison. The mole fractions of the CIGS films were measured by depth profiling based-SIMS, AES and XPS. The mole fractions were also measured by non-destructive X-Ray Fluorescence (XRF) Analysis and Electron Probe Micro Analysis (EPMA) with Energy Dispersive X-ray Spectrometry (EDX). In this key comparison, the average degrees of equivalence uncertainties for Cu, In, Ga and Se are 0.0093 mol/mol, 0.0123 mol/mol, 0.0047 mol/mol and 0.0228 mol/mol, respectively. These values are much smaller than that of Fe in a Fe-Ni alloy film in CCQM K-67 (0.0330 mol/mol). This means that the quantification of multi-element alloy films is possible by depth profiling analysis using the TNC method. KW - CIGS KW - Key comparison KW - CCQM KW - SIMS KW - XPS KW - AES KW - XRF KW - EPMA PY - 2016 UR - http://iopscience.iop.org/article/10.1088/0026-1394/53/1A/08011 DO - https://doi.org/10.1088/0026-1394/53/1A/08011 SN - 0026-1394 SN - 1681-7575 VL - 53, Technical Supplement SP - Article 08011, 1 EP - 19 PB - IOP Publishing AN - OPUS4-38110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Puthiyaveettil, N. A1 - Thomas, K. R. A1 - Myrach, Philipp A1 - Ziegler, Mathias A1 - Rajagopal, P. A1 - Balasubramaniamam, K. T1 - Defect detection in steel bars up to 600 °C using laser line thermography N2 - Crack detection in steel bars at high surface temperatures is a critical problem in any manufacturing industry. Surface breaking cracks are the major problems during the billet casting. Many NDT techniques are proven its capability in crack detection at room temperature. Here, we are demonstrating the possibility of exposure of cracks using laser line thermography at higher surface temperatures (up to 600 °C). A continuous-wave (CW) laser is used to excite the sample kept at higher surface temperatures. The temperature distribution over the sample due to the laser line scanning is captured using a temperature calibrated infrared (IR) thermal camera. The response of the sample temperature in crack detection is investigated using a validated FE model. The impact of the oxide layer in crack detection is investigated by using two types of samples; one without any oxide layer and the second is with the oxide layer. The influence of laser power in the detection of defects at high temperatures is studied. 3D numerical models were developed for the cases; when the sample is with oxide layer and without any oxide layer for a better understanding of physics. The surface temperature rise due to laser heating is higher for the scaled sample compared to the no-scale sample. The presence of the oxide layer above the parent metal will reduce the reflectivity of the surface. Lower reflectivity will lead to increased absorption of incident energy so that the surface temperature rise will be higher than the surface with no scale. Thermal contrast linearly depends on laser power, which means higher laser power will increase the defect detectability even at a higher surface temperature. KW - Laser thermography KW - High temperature KW - Modeling KW - Surface cracks KW - Non-destructive testing PY - 2020 DO - https://doi.org/10.1016/j.infrared.2020.103565 SN - 1350-4495 VL - 111 SP - 103565 PB - Elsevier B.V. AN - OPUS4-51573 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wirth, Thomas A1 - Beck, Uwe A1 - Hoffmann, V. A1 - Kurt, R. A1 - Kämmer, K. A1 - Thielsch, R. T1 - Interference Phenomena at Transparent Layers in Glow Discharge Optical Emission Spectrometry KW - Glow discharge optical emission spectroscopy KW - Depth profile KW - Interference KW - Transparent layers KW - Layer thickness KW - Refractive index KW - GD-OES PY - 1999 SN - 0003-7028 SN - 1943-3530 VL - 53 IS - 8 SP - 987 EP - 990 PB - Society for Applied Spectroscopy CY - Frederick, Md. AN - OPUS4-777 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Thomas, Hans-Martin A1 - Dey, Anika A1 - Pohl, Rainer A1 - Heyder, R. A1 - Krull, R. A1 - Dilz, K. T1 - Früherkennung von Rollkontakt-Ermüdung (RCF) in Eisenbahnschienen N2 - Infolge der Betriebsbeanspruchung unterliegen Eisenbahnschienen an ihrer Fahrkante sog. Rollkontakt-Ermüdung. Diese entsteht bevorzugt in Bögen durch eine Kaltverformung des Schienenstahls und zeigt sich anfänglich in einer erhöhten Verfestigung des kontaktbeanspruchten Oberflächenbereichs. Im weiteren Verlauf entstehen zahlreiche, flach in das Schieneninnere verlaufende Risse –sog. Head Checks. Diese Risse neigen ab einem gewissen Stadium dazu, in das Innere der Schiene abzukippen, was im Endstadium zu einem Schienenbruch führen kann. Seit einigen Jahren wird in Deutschland bei der DB AG das Wirbelstromverfahren erfolgreich zur zerstörungsfreien Prüfung der Schädigungstiefe von Head Checks eingesetzt. Hiermit wurde u. A. angestrebt, zuverlässige Planungsgrößen für den Einsatz von Instandhaltungsmaßnahmen zu erhalten, durch deren gezielten Einsatz ein weiteres Risswachstum wirkungsvoll unterbunden werden kann. Bereits bei einem der ersten systematischen Einsätze der Wirbelstromprüfung an einer Bogenstrecke mit hohem Betriebsaufkommen wurde auffällig, dass die Ermüdungsrisse nicht gleichmäßig entlang des Bogens verteilt auftraten, sondern sich auf kurze Distanzen Anhäufungen von Rissbefall mit intakten, unbefallenen Abschnitten abwechselten. Solch wellenförmiges Auftreten von Head Checks wurde auch in den nachfolgenden Prüfergebnissen der Wirbelstromprüfung vielerorts beobachtet. Aus der Literatur war bekannt, dass sich die Ermüdungsrisse bevorzugt in verfestigten Materialzonen bilden. Mit Hilfe von Härtemessungen konnte an verlegten und befahrenen Schienen gezeigt werden, dass die unbefallenen Zonen etwa die Grundhärte des Schienenwerkstoffes aufwiesen, während die mit Ermüdungsrissen befallenen Zonen um ca. 10 – 25% erhöhte Härtewerte aufwiesen. Die Wirbelstromprüfung reagiert sehr empfindlich auf Veränderungen der Materialeigenschaften. Somit lassen sich Verfestigungen der o. g. Art leicht auch ohne jedes Vorhandensein von Ermüdungsrissen bereits nachweisen. Im Zuge einer längerfristigen Beobachtung einer neu gebauten Strecke konnte herausgefunden werden, dass sich nach einer gewissen Betriebszeit wellenförmig verteilte Zonen mit Prüfsignalen, die auf Verfestigungen schließen lassen auftraten. Im weiteren zeitlichen Ablauf bildeten sich Ermüdungsrisse tatsächlich in den vorher bestimmten Stellen mit Verfestigung, während die Zonen ohne diese Prüfsignale weitgehend rissfrei blieben. Diese Ergebnisse zeigen, dass die Wirbelstromprüfung das Potential besitzt, mögliche Orte der Entstehung von Ermüdungsrissen in einem extrem frühzeitigen Stadium nachzuweisen. T2 - DACH-Jahrestagung 2008 - Zerstörungsfreie Materialprüfung, ZfP in Forschung, Entwicklung und Anwendung CY - St. Gallen, Schweiz DA - 2008-04-28 KW - Wirbelstromprüfung KW - Rollkontaktermüdung KW - Head Checks KW - Eisenbahnschiene KW - Kaltverfestigung PY - 2008 SN - 978-3-940283-09-2 IS - DGZfP-BB-113 (Mi.3.A.1.) SP - 501 EP - 510 AN - OPUS4-17982 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K.J. A1 - Jang, J. S. A1 - Kim, A. S. A1 - Suh, J.K. A1 - Chung, Y.-D. A1 - Hodoroaba, Vasile-Dan A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Kang, H. J. A1 - Popov, O. A1 - Popov, I. A1 - Kuselman, I. A1 - Lee, Y. H. A1 - Sykes, D. E. A1 - Wang, M. A1 - Wang, H. A1 - Ogiwara, T. A1 - Nishio, M. A1 - Tanuma, S. A1 - Simons, D. A1 - Szakal, C. A1 - Osborn, W. A1 - Terauchi, S. A1 - Ito, M. A1 - Kurokawa, A. A1 - Fujiimoto, T. A1 - Jordaan, W. A1 - Jeong, C. S. A1 - Havelund, R. A1 - Spencer, S. A1 - Shard, A. A1 - Streeck, C. A1 - Beckhoff, B. A1 - Eicke, A. A1 - Terborg, R. T1 - CCQM pilot study P-140: Quantitative surface analysis of multi-element alloy films N2 - A pilot study for the quantitative surface analysis of multi-element alloy films has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of this pilot study is to ensure the equivalency in the measurement capability of national metrology institutes for the quantification of multi-element alloy films. A Cu(In,Ga)Se2 (CIGS) film with non-uniform depth distribution was chosen as a representative multi-element alloy film. The atomic fractions of the reference and the test CIGS films were certified by isotope dilution - inductively coupled plasma/mass spectrometry. A total number counting (TNC) method was used as a method to determine the signal intensities of the constituent elements, which are compared with their certified atomic fractions. The atomic fractions of the CIGS films were measured by various methods, such as Secondary Ion Mass Spectrometry (SIMS), Auger Electron Spectroscopy (AES), X-ray Photoelectron Spectroscopy (XPS), X-Ray Fluorescence (XRF) analysis and Electron Probe Micro Analysis (EPMA) with Energy Dispersive X-ray Spectrometry (EDX). Fifteen laboratories from eight National Metrology Institutes (NMIs), one Designated Institute (DI) and six non-NMIs participated in this pilot study. Although the average atomic fractions of 18 data sets showed rather poor relative standard deviations of about 5.5 % to 6.8 %, they were greatly improved to about 1.5 % to 2.2 % by excluding 5 strongly deviating data sets from the average atomic fractions. In this pilot study, the average expanded uncertainties of SIMS, XPS, AES, XRF and EPMA were 3.84%, 3.68%, 3.81%, 2.88% and 2.90%, respectively. These values are much better than those in the key comparison K-67 for composition of a Fe-Ni alloy film. As a result, the quantification of CIGS films using the TNC method was found to be a good candidate as a subject for a CCQM key comparison. KW - CCQM KW - Pilot study KW - Surface analysis KW - Alloy films KW - CIGS PY - 2015 DO - https://doi.org/10.1088/0026-1394/52/1A/08017 SN - 0026-1394 SN - 1681-7575 VL - 52 IS - Technical Supplement SP - Article 08017 PB - Inst. of Physics Publ. CY - Bristol AN - OPUS4-35306 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kraffert, K. A1 - Karg, M. A1 - Schmack, R. A1 - Clavel, G. A1 - Boissiere, C. A1 - Wirth,, Thomas A1 - Pinna, N. A1 - Kraehnert, R. T1 - Stabilization of Mesoporous Iron Oxide Films against Sintering and Phase Transformations via Atomic Layer Deposition of Alumina and Silica N2 - The stabilization of crystal phases and nanostructured morphologies is an essential topic in application-driven design of mesoporous materials. Many applications, e.g. catalysis, require high temperature and humidity. Typical metal oxides transform under such conditions from a metastable, low crystal-line material into a thermodynamically more favorable form, i.e. from ferrihy-drite into hematite in the case of iron oxide. The harsh conditions induce also a growth of the crystallites constituting pore walls, which results in sintering and finally collapse of the porous network. Herein, a new method to stabi-lize mesoporous templated metal oxides against sintering and pore collapse is reported. The method employs atomic layer deposition (ALD) to coat the internal mesopore surface with thin layers of either alumina or silica. The authors demonstrate that silica exerts a very strong influence: It shifts hematite formation from 400 to 600 °C and sintering of hematite from 600 to 900 °C. Differences between the stabilization via alumina and silica are rationalized by a different interaction strength between the ALD material and the ferrihydrite film. The presented approach allows to stabilize mesoporous thin films that require a high crystallization temperature, with submonolayer quantity of an ALD material, and to apply mesoporous materials for high temperature applications. KW - Mesoporous oxides KW - Atomic layer deposition KW - Stabilization PY - 2018 DO - https://doi.org/10.1002/admi.201800360 VL - 5 IS - 14 SP - 1800360-1 EP - 1800360-9 PB - Wiley-VCH AN - OPUS4-47869 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gerlitzke, A.-K. A1 - Nörthemann, K. A1 - Lang, M. A1 - Milstrey, M. A1 - Kaufer, R. A1 - Woratz, M. A1 - Banach, Ulrich A1 - Hübert, Thomas A1 - Moritz, W. T1 - Long-term stability of the low energy hydrogen sensor N2 - A silicon MIS-structure prepared with thin layers of the super-ionic conductor LaF3 and Pd is used to detect hydrogen. The sensor is able to detect hydrogen in a concentration range from below one ppm to the lower flammable limit in air which is 4 vol.-%. The chip operates at room temperature which results in an extremely low energy consumption compared to other hydrogen sensors. Only once per day a short heating pulse is necessary to reactivate the sensor chip. In cooperation with the BAM, a long-term experiment was carried out. The duration of the measurement was about three months, with a hydrogen exposure every two weeks. The sensor signal remained stable over the measured period. T2 - IMCS 2012 - 14th International meeting on chemical sensors CY - Nuremberg, Germany DA - 20.05.2012 KW - Hydrogen detection KW - Long-term measurement KW - MIS-structure KW - Low energy sensor PY - 2012 SN - 978-3-9813484-2-2 DO - https://doi.org/10.5162/IMCS2012/P2.5.1 SP - 1571 EP - 1574 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-26177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lang, M. A1 - Banach, Ulrich A1 - Nörthemann, K. A1 - Gerlitzke, A.-K. A1 - Milstrey, M. A1 - Kaufer, R. A1 - Woratz, M. A1 - Hübert, Thomas A1 - Moritz, W. T1 - Long-term stability of a MEIS low energy hydrogen sensor N2 - A hydrogen sensor based on a silicon Metal/Solid Electrolyte/Insulator/Semiconductor (MEIS) structure with thin layers of the super-ionic conductor LaF3 and Pd gate metal was investigated in a hybrid structure on a resistance heater mounted on a ceramic substrate. The sensor was operated at room temperature, however, a short heating impulse once a day ensures a fast and reproducible dynamic behavior. The sensor was characterized in the concentration range typical for alarm levels up to 40% of the lower flammability limit and shows a logarithmic dependency of the sensor signal from the hydrogen concentration and a mean sensitivity of about 140 mV/decade. The response time (t90) is about 8 s. In a long term test for a period of three month, the sensor was exposed to hydrogen every two weeks. The sensor signal was shown to be stable in dynamic behavior, sensitivity and signal difference. KW - Hydrogen detection KW - Long-term measurement KW - MEIS-structure KW - Low energy sensor PY - 2013 DO - https://doi.org/10.1016/j.snb.2012.12.081 SN - 0925-4005 SN - 1873-3077 VL - 187 SP - 395 EP - 400 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-29223 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Puthiyaveettil, N. A1 - Thomas K, R. A1 - Unnikrishnakurup, S. A1 - Myrach, Philipp A1 - Ziegler, Mathias A1 - Balasubramaniam, K. T1 - Laser line scanning thermography for surface breaking crack detection modeling and experimental study N2 - Crack detection in metallic samples at high surface temperature, hostile and hazardous environments, etc. is challenging situation in any manufacturing industries. Most of the present NDE methods are suitable only for lower surface temperatures, especially room temperature. In this situation, we need a fast and non-contact NDT method which can be applied even in high sample surface temperature. Laser thermography is one of the techniques having a high potential in non-contact inspection. As a preliminary investigation, in this article, we have studied the potentiality of laser line thermography in crack detection at room temperature. In laser line thermography, a continuous wave (CW) laser is used to generate a laser line, which in turn is used to scan the metal surface. The heat distribution over the sample surface is recorded by an infrared thermal (IR) camera. Two different approaches are reported in this work. Firstly, a stationary laser line source and its interaction with cracks; secondly, moving laser line source scanning over a surface with crack. When the distance between crack centre to laser line centre increases, crack detectability will decrease; and when laser power increases, crack detectability will increase. A dedicated image processing algorithm was developed to improve the detectability of the cracks. To understand the heat transfer phenomenon, a simplified 3D model for laser thermography was developed for the heat distribution during laser heating and was validated with experimental results. Defects were incorporated as a thermally thin resistive layer (TTRL) in numerical modeling, and the effect of TTRL in heat conduction is compared with experimental results. KW - Thermography KW - Laser Thermography KW - Cracks KW - FEM KW - NDT PY - 2019 DO - https://doi.org/10.1016/j.infrared.2019.103141 VL - 104 SP - 103141 PB - Elsevier B.V. AN - OPUS4-49941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eissel, A. A1 - Engelking, Lorenz A1 - Gustus, R. A1 - Treutler, K. A1 - Wesling, V. A1 - Schröpfer, Dirk A1 - Kannengießer, Thomas T1 - Alloy modification for additive manufactured Ni alloy components—part I: effect on microstructure and hardness of Invar alloy N2 - Alloy 36 (1.3912), also known as “Invar,” is an alloy with 36% nickel. The alloy has a remarkably low thermal expansion coefficient in certain temperature ranges. This peculiarity is called the invar effect, which was discovered in 1896 by the Swiss physicist Charles Édouard Guillaume. Therefore, it is used in applications in which dimensional stability is critical, such as molding tools for composite materials in aerospace, automotive applications, or liquified natural gas (LNG) cargo tanks. Moreover, increasingly complex structures and the optimization of resource efficiency also require additive manufacturing steps for the production or repair of components. Additively manufactured components have a heterogeneous microstructure and anisotropic mechanical properties. In addition, the manufactured components require subsequent machining surface finishing, like finish milling, to achieve their final contour. Nickel iron alloys are difficult to machine. Additionally, inhomogeneous microstructure may lead to unstable cutting forces and conditions. In part I of this investigation, the initial alloy 36 is modified with the elements Ti, Zr, and Hf up to a maximum of 0.33 wt.-%. The influence of the modification elements on the microstructure as well as on the hardness of the AM components is examined. Furthermore, one modification is applied to metal arc welding process and investigated. Part II focuses on the effect of the alloy modifications on machinability as well as on the surface integrity of plasma-transferred-arc-welded (PTA) and finish milled invar components. T2 - 75th IIW Annual Assembly CY - Tokyo, Japan DA - 17.07.2022 KW - Alloy modification KW - Alloy 36 KW - Plasma-transferred arc welding PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571777 DO - https://doi.org/10.1007/s40194-023-01510-w SN - 0043-2288 SP - 1 EP - 9 PB - Springer CY - Heidelberg AN - OPUS4-57177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kailasam, K. A1 - Mesch, M. B. A1 - Möhlmann, Lennart A1 - Baar, M. A1 - Blechert, S. A1 - Schwarze, M. A1 - Schröder, M. A1 - Schomäcker, R. A1 - Senker, J. A1 - Thomas, A. T1 - Donor–acceptor-type heptazine-based polymer networks for photocatalytic hydrogen evolution N2 - A heptazine-based polymer network (HMP-3) with a donor–acceptor (D–A) structure was prepared and tested as catalyst for photocatalytic hydrogen evolution from water. Compared to other heptazine-based materials, which are typically prepared at high temperatures and have recently received much interest as metal-free photocatalysts, the low-temperature protocol applied here allows the defined introduction of organic functional groups within the polymer backbone. The structure of HMP-3 contains alternating heptazine and benzothiadiazole moieties as electron acceptors connected by aminobenzene bridges as electron donors. The resulting material leads to enhanced hydrogen evolution compared to graphitic carbon nitride materials prepared at high temperatures (>500 8C) most probably because of the stabilization of photogenerated charge carriers in the D–A structure. KW - Photocatalysis KW - Water splitting KW - Water reduction KW - Carbon nitride PY - 2016 DO - https://doi.org/10.1002/ente.201500478 VL - 4 IS - 6 SP - 744 EP - 750 PB - Wiley AN - OPUS4-36915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unger, Wolfgang A1 - Schwarz, F. A1 - Heinrich, Thomas A1 - Kaufmann, J. O. A1 - Lippitz, Andreas A1 - Puttreddy, R. A1 - Rissanen, K. A1 - Schalley, C. A. T1 - Photocontrolled on-surface pseudorotaxane formation with well-ordered macrocycle multilayers N2 - The photoinduced pseudorotaxane formation between a photoresponsive axle and a tetralactam macrocycle was investigated in solution and on glass surfaces with immobilized multilayers of macrocycles. In the course of this reaction, a novel photoswitchable binding station with azobenzene as the photoswitchable unit and diketopiperazine as the binding station was synthesized and studied by NMR and UV/Vis spectroscopy. Glass surfaces have been functionalized with pyridine-terminated SAMs and subsequently withmultilayers of macrocycles through layer-by-layer self assembly. A preferred orientation of the macrocycles could be confirmed by NEXAFS spectroscopy. The photocontrolled Deposition of the axle into the surface-bound macrocycle-multilayers was monitored by UV/Vis spectroscopy and led to an increase of the molecular order, as indicated by more substantial linear dichroism effects in angle-resolved NEXAFS spectra. KW - Well-ordered macrocycle multilayers KW - XPS KW - NEXAFS PY - 2016 DO - https://doi.org/10.1002/chem.201603156 SN - 0947-6539 SN - 1521-3765 VL - 22 IS - 40 SP - 14383 EP - 14389 PB - Wiley-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-38270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröpfer, Dirk A1 - Treutler, K. A1 - Börner, Andreas A1 - Gustus, R. A1 - Kannengießer, Thomas A1 - Wesling, V. A1 - Maus-Friedrichs, W. T1 - Surface finishing of hard-to-machine cladding alloys for highly stressed components N2 - The supply and processing of materials for highly stressed components are usually cost-intensive. Efforts to achieve cost and resource efficiency lead to more complex structures and contours. Additive manufacturing steps for component repair and production offer significant economic advantages. Machining needs to be coordinated with additive manufacturing steps in a complementary way to produce functional surfaces suitable for the demands. Regarding inhomogeneity and anisotropy of the microstructure and properties as well as production-related stresses, a great deal of knowledge is still required for efficient use by small- and medium-size enterprises, especially for the interactions of subsequent machining of these difficult-to-machine materials. Therefore, investigations on these influences and interactions were carried out using a highly innovative cost-intensive NiCrMo alloy (IN725). These alloys are applied for claddings as well as for additive component manufacturing and repair welding using gas metal arc welding processes. For the welded specimens, the adequate solidification morphology, microstructure and property profile were investigated. The machinability in terms of finishing milling of the welded surfaces and comparative analyses for ultrasonic-assisted milling processes was examined focussing on surface integrity. It was shown that appropriate cutting parameters and superimposed oscillating of the milling tool in the direction of the tool rotation significantly reduce the mechanical loads for tool and workpiece surface. This contributes to ensure a high surface integrity, especially when cutting has to be carried out without cooling lubricants. KW - WAAM KW - IN725 KW - Machining KW - Ultrasonic-assisted milling KW - Residual stresses KW - Cutting forces KW - Surface integrity KW - Microstructure PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524872 DO - https://doi.org/10.1007/s00170-021-06815-y VL - 114 IS - 5-6 SP - 1427 EP - 1442 PB - Springer AN - OPUS4-52487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Wirth, Thomas A1 - Terborg, R. A1 - Kim, K.J. A1 - Unger, Wolfgang T1 - Measurement of atomic fractions in Cu(In,Ga)Se2 films by Auger Electron Spectroscopy (AES) and Energy Dispersive Electron Probe Microanalysis (ED-EPMA) N2 - A pilot study (PS) has been performed under the Consultative Committee for Amount of Substance (CCQM) / Surface Analysis Working Group (SAWG) with the objective to compare the atomic fractions of Cu, In, Ga and Se in CIGS alloy films. Four polycrystalline CIGS films with different atomic fractions were fabricated by variation of the relative atomic fraction of Ga on 100 mm x 100 mm soda-lime glass (SLG) substrates. Similar to real solar cells the atomic fractions of the four elements (Cu, In, Ga, Se) are not homogeneous with depth. For the analysis of the CIGS layers of about 2 μm thickness depth profiling with surface analysis techniques such as XPS, AES and SIMS was recommended. A CIGS alloy reference sample with atomic fractions certified by isotope dilution ICP-MS at KRISS has been also put at disposal by the coordinator of the comparison. The certified values were close to the atomic fractions of the samples to be analyzed. Hence, the atomic fractions of Cu, In, Ga and Se in the CIGS films could be determined by the relative sensitivity factors (RSF) derived from the reference CIGS film. The total ion intensities of the constituent elements were obtained by the total number counting (TNC) method. KW - Interlaboratory comparison KW - Auger Electron Spectroscopy (AES) KW - EDX KW - EPMA KW - CIGS KW - CCQM PY - 2014 DO - https://doi.org/10.1017/S1431927614003730 SN - 1431-9276 SN - 1435-8115 VL - 20 IS - Suppl. S 3 SP - 402 EP - 403 PB - Cambridge University Press CY - New York, NY AN - OPUS4-31339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -