TY - JOUR A1 - Epishin, A. I. A1 - Link, T. A1 - Nolze, Gert A1 - Svetlov, I. L. A1 - Bokshtein, B. S. A1 - Rodin, A. O. A1 - Saliwan Neumann, Romeo A1 - Oder, Gabriele T1 - Diffusion processes in multicomponent nickel-base superalloy-nickel system JF - The Physics of Metals and Metallography N2 - Optical and scanning electron microscopy, as well as electron microprobe analysis and electron backscatter diffraction, have been used to study diffusion processes that occur in a diffusion pair that consistsof a single-crystal CMSX-10 nickel-base superalloy and polycrystalline nickel, at temperatures of 1050–1250°C. It has been found that, in this system, the distributions of γ-stabilizing elements (Cr, Co, W, and Re) are described by the Boltzmann solution for diffusion between two semiinfinite plates of a binary alloy. The processing of these distributions has shown that the diffusion coefficients of Cr, Co, W, and Re in the multicomponent system are close to those in binary alloys of these elements with Ni. The diffusion redistribution of the elements leads to the dissolution of the γ′ phase in the nickel-base superalloy, growth of nickel grains toward the superalloy constituent of the diffusion pair, and the formation of porosity on both sides of the migrating interface, which is determined from a crystal misorientation of the alloy single crystal and nickel grains. KW - Ni-base superalloy KW - Interface KW - Diffusion KW - Phase transformation KW - Porosity PY - 2014 SN - 0031-918X VL - 115 IS - 1 SP - 21 EP - 29 AN - OPUS4-37980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Chen, W. A1 - Darowski, N. A1 - Zizak, I. A1 - Schumacher, G. A1 - Klingelhöffer, Hellmuth A1 - Wanderka, N. A1 - Neumann, W. ED - Chandra, T. ED - Torralba, Jose M. ED - Sakai, T. T1 - Measurement of Gamma/Gamma' Lattice Mismatch in Creep Deformed SIngle Crystal Superalloy SC16 Using Synchrotron X-Radiation T2 - THERMEC 2003 T2 - International Conference on Processing & Manufacturing of Advanced Materials CY - Leganés, Spain DA - 2003-07-07 KW - Superalloy KW - Lattice mismatch KW - High temperature KW - Creep deformed PY - 2003 SN - 0-87849-919-9 SN - 0255-5476 N1 - Serientitel: Materials science forum – Series title: Materials science forum IS - 426-432/5 SP - 4555 EP - 4560 PB - Trans Tech Publ. CY - Uetikon-Zürich AN - OPUS4-2790 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Darowski, N. A1 - Zizak, I. A1 - Schumacher, G. A1 - Wanderka, N. A1 - Klingelhöffer, Hellmuth A1 - Chen, W. A1 - Neumann, W. T1 - Lattice mismatch in creep-deformed single crystal superalloy SC16 T2 - BESSY highlights - annual report 2002 PY - 2003 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2002.pdf#page=283 SN - 0179-4159 SP - 283 EP - 285 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-2491 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Treimer, W. A1 - Feye–Treimer, U. A1 - Radke, C. A1 - Hilger, A. A1 - Neumann, O. A1 - Manke, I. A1 - Haibel, A. A1 - Rack, A. A1 - Riesemeier, Heinrich T1 - Investigations of mamma biopsies by means of µ-tomography T2 - BESSY highlights - annual report 2004 PY - 2005 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2004.pdf#page=452 SN - 0179-4159 SP - 452 EP - 453 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-7383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schumacher, G. A1 - Darowski, N. A1 - Zizak, I. A1 - Klingelhöffer, Hellmuth A1 - Chen, W. A1 - Neumann, W. ED - Chandra, T. T1 - Time dependence of y/y' Lattice Mismatch in Creep-deformed Single Crystal Superalloy SC16 at 1173 K T2 - THERMEC 2006 T2 - 5th International Conference on Processing & Manufacturing of Advanced Materials CY - Vancouver, Canada DA - 2006-07-04 KW - Superalloys KW - Lattice distortion KW - SC16 KW - Creep-deformation KW - X-ray diffraction PY - 2007 SN - 0-87849-428-6 SN - 0255-5476 N1 - Serientitel: Materials science forum – Series title: Materials science forum VL - 539-543/3 IS - 539/543 SP - 3059 EP - 3063 PB - Trans Tech Publ. CY - Stafa-Zürich AN - OPUS4-14032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schumacher, G. A1 - Darowski, N. A1 - Zizak, I. A1 - Klingelhöffer, Hellmuth A1 - Chen, W. A1 - Neumann, W. ED - Chandra, T. T1 - Temperature Dependence of Lattice Distortion in Strongly Creep-deformed Single Crystal Superalloy SC16 T2 - THERMEC 2006 T2 - 5th International Conference on Processing & Manufacturing of Advanced Materials CY - Vancouver, Canada DA - 2006-07-04 KW - Superalloys KW - SC16 KW - Lattice distortion KW - Creep-deformation KW - X-ray-diffraction PY - 2007 SN - 0-87849-428-6 SN - 0255-5476 N1 - Serientitel: Materials science forum – Series title: Materials science forum VL - 539-543/3 IS - 539/543 SP - 3048 EP - 3052 PB - Trans Tech Publ. CY - Stafa-Zürich AN - OPUS4-14033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Neuhaus, B. A1 - Allspach, A. A1 - Bartsch, P. A1 - Burckhardt, D. A1 - Coleman, C.O. A1 - Fries, I. A1 - Fuchs, R. A1 - Gudo, M. A1 - Kotrba, M. A1 - Mentjes, M. A1 - Moore, S. A1 - Neumann, D. A1 - Oberer, C. A1 - Potthast, A. A1 - Riedel, Juliane A1 - Rudolf, R. A1 - Schnalke, T. A1 - Schönbohm, D. A1 - Schuda, M. A1 - van Dam, A. A1 - Widulin, N. T1 - KUR-Projekt: Aufbau und öffentliche Kommunikation eines wissenschafts-basierten Sammlungsmanagements für naturkundliche Nasssammlungen N2 - Im Rahmen eines von der Kulturstiftung des Bundes und der Kulturstiftung der Länder geförderten Projektes zum Erhalt naturkundlicher Nasssammlungen wurden 1) der Zustand der Sammlungen bewertet (Profiling; Analyse der Vergällungsmittel), 2) über Workshops Expertenwissen in das Projekt gebracht, 3) neue archivbeständige Materialien und Managementmaßnahmen eingeführt (Borosilikat-Gläser und - Röhrchen, Augenwatte, Tefloneinlagen, Japanpapier, archivbeständige Kleber und Papier, Etikettenaufbewahrung; digitales Dichtemessgerät, Alcomon-Indikator, Kontrollintervalle), 4) Erhaltungsmaßnahmen zur langfristigen Konservierung in großem Umfange durchgeführt (Messen der Alkoholkonzentration, Umsetzen von Präparaten in geeignetere Gefäße, Wiederverschluss von Schaugläsern) und 5) Erfahrungen und Diskussionsergebnisse zusammengestellt, nicht ohne auf Wissenslücken und wünschenswerte Forschungsaspekte hinzuweisen. Das Projekt profitierte besonders von der Expertise aus den Materialwissenschaften und der Papierrestaurierung. Das Museum für Naturkunde Berlin kooperierte eng mit dem Berliner Medizinhistorischen Museum der Charité, der Zoologischen Staatssammlung München und dem Forschungsinstitut Senckenberg in Frankfurt. Letzteres Museum führte ein eigenes, themenverwandtes KUR-Projekt Restauration der Sammlungen 'Vergleichende Anatomie, Embryologie und Histologie' des Naturmuseums Senckenberg durch. KW - Nasssammlung KW - Ethanol KW - Vergällungsmittel PY - 2012 DO - https://doi.org/10.5165/hawk-hhg/epublication/44 SP - 1 EP - 32 AN - OPUS4-25491 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epishin, A. A1 - Link, T. A1 - Svetlov, I. L. A1 - Nolze, Gert A1 - Saliwan Neumann, Romeo A1 - Lucas, H. T1 - Mechanism of porosity growth during homogenisation in single crystal nickel-based superalloys JF - International Journal of Materials Research N2 - Several mechanisms for porosity growth in single crystal nickel-based superalloys during homogenisation heat treatment have been proposed in the literature. They were carefully checked using different experimental methods, namely quantitative light microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and density measurements. It is shown that the main mechanism is the Kirkendall–Frenkel effect, i.e. generation of voids due to uncompensated efflux of Al atoms from dissolving γ/γ′-eutectic areas. The Al diffusion is supported by the afflux of vacancies from surrounding γ-matrix which results in porosity growth. This conclusion is confirmed by the estimation of the vacancy afflux towards the dissolving eutectic. KW - Ni-base superalloy KW - Eutectic KW - Vacancies KW - Porosity PY - 2013 VL - 104 IS - 8 SP - 776 EP - 782 PB - Carl Hanser Verlag AN - OPUS4-37983 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Omidalizarandi, M. A1 - Herrmann, Ralf A1 - Kargoll, B. A1 - Marx, S. A1 - Paffenholz, J. A1 - Neumann, I. T1 - A validated robust and automatic procedure for vibration analysis of bridge structures using MEMS accelerometers JF - Journal of Applied Geodesy N2 - Today, short- and long-term structural health monitoring (SHM) of bridge infrastructures and their safe, reliable and cost-effective maintenance has received considerable attention. From a surveying or civil engineer’s point of view, vibration-based SHM can be conducted by inspecting the changes in the global dynamic behaviour of a structure, such as natural frequencies (i. e. eigenfrequencies), mode shapes (i. e. eigenforms) and modal damping, which are known as modal parameters. This research work aims to propose a robust and automatic vibration analysis procedure that is so-called robust time domain modal parameter identification (RT-MPI) technique. It is novel in the sense of automatic and reliable identification of initial eigenfrequencies even closely spaced ones as well as robustly and accurately estimating the modal parameters of a bridge structure using low numbers of cost-effective micro-electro-mechanical systems (MEMS) accelerometers. To estimate amplitude, frequency, phase shift and damping ratio coefficients, an observation model consisting of: (1) a damped harmonic oscillation model, (2) an autoregressive model of coloured measurement noise and (3) a stochastic model in the form of the heavy-tailed family of scaled t-distributions is employed and jointly adjusted by means of a generalised expectation maximisation algorithm. Multiple MEMS as part of a geo-sensor network were mounted at different positions of a bridge structure which is precalculated by means of a finite element model (FEM) analysis. At the end, the estimated eigenfrequencies and eigenforms are compared and validated by the estimated parameters obtained from acceleration measurements of high-end accelerometers of type PCB ICP quartz, velocity measurements from a geophone and the FEM analysis. Additionally, the estimated eigenfrequencies and modal damping are compared with a well-known covariance driven stochastic subspace identification approach, which reveals the superiority of our proposed approach. We performed an experiment in two case studies with simulated data and real applications of a footbridge structure and a synthetic bridge. The results show that MEMS accelerometers are suitable for detecting all occurring eigenfrequencies depending on a sampling frequency specified. Moreover, the vibration analysis procedure demonstrates that amplitudes can be estimated in submillimetre range accuracy, frequencies with an accuracy better than 0.1 Hz and damping ratio coefficients with an accuracy better than 0.1 and 0.2 % for modal and system damping, respectively. KW - Vibration analysis KW - Automatic modal parameters identification KW - MEMS KW - FEM analysis KW - Bridge monitoring PY - 2020 UR - https://www.degruyter.com/view/journals/jag/14/3/article-p327.xml DO - https://doi.org/10.1515/jag-2020-0010 SN - 1862-9016 VL - 14 IS - 3 SP - 1 EP - 28 PB - De Gruyter CY - Berlin AN - OPUS4-51338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -