TY - JOUR A1 - Midtlyng, Jan A1 - Epishin, A. I. A1 - Petrushin, N. V. A1 - Link, T. A1 - Nolze, Gert A1 - Svetlov, I. L. A1 - Reimers, W. T1 - Creep behavior of a γ΄-strengthened Co-base alloy with zero γ/γ΄-lattice misfit at 800 °C, 196 MPa N2 - Deformation and structural behavior of an experimental γ΄-strengthened Co-base alloy during creep at 800 °C and 196 MPa have been investigated. The characteristic features of this alloy are zero γ/γ΄-lattice misfit and a fine γ/γ΄-microstructure. In the initial condition, the γ΄-precipitates in this alloy are small (size of about 100 nm), have polyhedral morphology, and are separated by the very narrow c-channels (width of about 10 nm). The tests performed up to about 1% creep strain (about 500 h creep time) gave creep curves with a slow constant strain rate and without an apparent transient creep, typical for superalloys with nonzero misfit. In this initial stage of creep, entering of the narrow γ-channels by dislocations is blocked by a strong Orowan force. The micromechanism of creep was identified as an octahedral glide of h011i superdislocations simultaneously in two phases, γ and γ΄. The γ/γ΄-microstructure with zero misfit shows no rafting but rapidly coarsens isotropically. It is concluded that zero misfit is beneficial at the initial stages of the creep but is unfavourable for longterm creep because of the continuous microstructural coarsening. KW - Co-Basis-Legierung KW - Gitterfehlpassung KW - Kriechen KW - Ausscheidung PY - 2017 DO - https://doi.org/10.1557/jmr.2017.424 SN - 0884-2914 SN - 2044-5326 VL - 32 IS - 24 SP - 4466 EP - 4474 PB - Cambridge Univ. Press CY - Cambridge AN - OPUS4-44027 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Femtosecond laser pulses for photovoltaic bottom-up strategies N2 - A bottom-up approach to produce arrays of indium islands on a molybdenum layer on glass using 30-fs laser pulses at 790 nm wavelength is presented. These islands can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide (CIGSe) used in photovoltaics. Molybdenum is the standard back contact material of CIGSe solar cells. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD. T2 - 10. Mittweidaer Lasertagung CY - Mittweida, Germany DA - 16.11.2017 KW - Copper-indium-gallium-diselenide KW - CIGSe KW - Femtosecond laser KW - Micro solar cell KW - Laser ablation PY - 2017 AN - OPUS4-42987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Andree, Stefan A1 - Heidmann, B. A1 - Ringleb, F. A1 - Eylers, K. A1 - Bonse, Jörn A1 - Boeck, T. A1 - Schmid, M. A1 - Krüger, Jörg T1 - Femtosecond laser pulses for photovoltaic bottom-up strategies N2 - A promising technology in photovoltaics is based on micro-concentrator solar cells, where the photovoltaic active area is realized as an array of sub-millimeter sized cells onto which the incident light is focused via microlenses. This approach allows to increase the cell efficiency and to realize much more compact modules compared to macroscopic concentrator devices. At the same time, expensive raw materials can be saved, which is of interest, for example, with respect to indium in the case of copper-indium-gallium-diselenide (CIGSe) thin film solar cells. Two methods to produce micro-sized precursors of CIGSe absorbers on molybdenum are presented using 30-fs laser pulses at 790 nm wavelength. On the one hand, a multi pulse surface structuring of the molybdenum film or the underlying glass substrate and a subsequent physical vapor deposition were used for a site-selective aggregation of indium droplets. On the other hand, a single pulse laser-induced forward transfer was utilized to selectively deposit combined copper-indium precursor pixels on the molybdenum back contact of the solar cell. Post-processing (selenization, isolation, contacting) of the laser-generated micro-sized precursors results in functional CIGSe solar cells. T2 - 10. Mittweidaer Lasertagung CY - Mittweida, Germany DA - 16.11.2017 KW - Copper indium gallium diselenide (CIGSe) KW - Micro solar cell KW - Femtosecond laser KW - Laser ablation KW - Laser-induced forward transfer (LIFT) PY - 2017 SN - 1437-7624 VL - 2 SP - 1 EP - 4 PB - Hochschule Mittweida CY - Mittweida AN - OPUS4-42988 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Krebber, Katerina T1 - Polymer optical fibers for sensing applications: Ionizing radiation monitoring N2 - In the last decades, considerable attention has been paid to the development of polymer optical fibers (POFs) that may in certain cases represent more suitable or cost-effective alternative to their glass-based counterparts. Among other applications, special attention was paid to the utilization of optical fiber sensors in radiation environments. A concept of attenuation-based radiation sensing with perfluorinated POFs is here presented as a potential candidate for low-cost easy-to-use on-line radiation monitoring system. T2 - The Fiber Society 2017 Spring Conference: Next Generation Fibers for Smart Products CY - Aachen, Germany DA - 17.05.2017 KW - Polymer optical fibers KW - Radiation monitoring KW - Cytop PY - 2017 SP - 50 AN - OPUS4-43026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Babutzka, Martin T1 - Prüfverfahren zur Bewertung der kathodischen Enthaftung bei organischen Beschichtungen – Eine kritische Betrachtung N2 - Im Vortrag werden mit Blick auf die geltenden Regelwerke und Normen die Unterschiede verschiedener Prüfmethoden zur kathodischen Enthaftung bei organischen Beschichtungen vorgestellt und deren Aussagekraft kritisch betrachtet. Am Beispiel von systematischen Versuchsreihen an einem Kurzzeittest werden die Grenzen einiger Methoden herausgearbeitet und die Anwendbarkeit für Reparaturbeschichtungen in Offshore-Bereich ausgelotet. T2 - Arbeitskreissitzung „Korrosionsuntersuchung und -überwachung“ des GfKORR e. V. CY - Magdeburg, Germany DA - 21.11.2017 KW - Kathodische Enthaftung KW - Cathodic delamination KW - Korrosionsprüfung KW - Corrosion testing KW - Organische Beschichtungen KW - Organic coatings PY - 2017 AN - OPUS4-43038 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Palkowski, Carsten A1 - Schlegel, Moritz-Caspar A1 - Akkerman, Floris A1 - Simo, Anne T1 - Telling the truth - Validity of energy efficiency values of heat pumps determined under laboratory conditions N2 - In this study, the test method EN 14825 for testing heat pumps is validated by verifying the sensitivity of the seasonal space heating energy efficiency ηs,(declared on the energy Efficiency label) in relation to the nominal heating capacity Pdesign. Therefore, the two major parts of the test method, the measurement part and the calculation part, were investigated. The calculation part was subjected to a sensitivity analysis in order to identify the properties of a heat pump which have a strong influence on ηs. The analysis revealed that the energy consumption in Special operating states, the duration in active-mode and seasonal performance values in active-mode (SCOPon) significantly affect the sensitivity of ηs. Especially short operating times, in which the heat pump is in active-mode, lead to large changes in ηs with varying Pdesign. In addition, the range of power of Pdesign turned out to have an increasing impact on ηs with decreasing Pdesign. For Pdesign values ≤10 kW, the sensitivity of ηs increases tremendously. Especially the determination of the ηs for devices with short operating times in active-mode (1400 h) and low values for Pdesign (≤10 kW)cannot be reproduced anymore. T2 - 9th international conference on energy efficiency in domestic appliances and lighting (EEDAL '17) CY - Irvine, CA, USA DA - 13.09.2017 KW - Circumvention KW - Energy efficiency KW - Energy labelling KW - Heat pumps KW - Test method standard optimization PY - 2017 SN - 978-92-79-77174-3 DO - https://doi.org/10.2760/113534 SN - 1831-9424 VL - 2017 IS - Part III SP - 1104 EP - 1112 AN - OPUS4-43833 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völzke, Holger A1 - Orellana Pérez, Teresa T1 - Latest developments in Germany concerning extended interim storage N2 - The presentation explains recent administrative developments in Germany concerning nuclear waste management and adresses national and European R&D funding concepts. National and international collaboration is explained followed by the latest update on long term metal seal investigations at BAM. Finally, fuel cladding failure mechanisms during long term dry storage and related R&D initiatives at BAM are explained. T2 - EPRI Extended Storage Collaboration Program (ESCP) International Subcommittee Meeting CY - Jeju, Korea DA - 15.09.2017 KW - Nuclear waste management KW - Long term storage KW - Spent fuel PY - 2017 AN - OPUS4-43793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Orellana Pérez, Teresa T1 - Perspectives on demonstrating fuel cladding integrity for extended dry interim storage in Germany N2 - The presentation highlights recent investigations by BAM on how to address fuel cladding integrity under long term dry storage conditions. National and European initiatives and research programs related to radioactive waste management and disposal are explained. T2 - EPRI Extended Storage Collaboration Program (ESCP) Winter Meeting 2017 CY - Charlotte, NC, USA DA - 14.11.2017 KW - Fuel cladding integrity KW - Extended interim storage KW - Spent fuel PY - 2017 AN - OPUS4-43795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völzke, Holger T1 - Update on long-term investigations of metal seals at BAM and future perspectives of spent fuel management in Germany N2 - The presentation focuses on the latest developments of the German nuclear waste management policy including restructering of responsible organizations and the restart of the repository site selection process for high level radioactive waste. The second part illustrates latest results of long term investigations of metal seals at BAM with regard to extended interim storage periods. T2 - EPRI Extended Storage Collaboration Program (ESCP) Winter Meeting 2017 CY - Charlotte, NC, USA DA - 14.11.2017 KW - Spent fuel KW - Metal seal KW - Extended interim storage PY - 2017 AN - OPUS4-43796 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scheidemann, Robert A1 - Qiao, Linan A1 - Müller, Karsten T1 - Comparison of experimental results and numerical simulations of penetration tests with damping concrete N2 - The shock absorbing material damping concrete is for the foundation in dry interim storage facilities for radioactive waste in Germany. In case of a potential cask drop damping concrete minimizes the mechanical loads to the cask. In course of safety analyzes this accident scenario is considered by numerical simulations using the finite element method. To get reliable results of numerical simulations a suitable material model is needed to take the characteristics of damping concrete into account. Due to the lack of sufficient material knowledge a research project was started to characterize the material’s behavior under different load conditions. This paper presents the test program to analyze the material behavior of damping concrete which is characterized by large volume change and strain rate hardening dependence. The determined Parameters were used to adapt an existing material model of the FE-code ABAQUS®. This model has to handle the mechanical damage behavior of damping concrete which occurs under compression and shear loads during a potential cask drop. To verify the material model numerical simulations are compared with dynamic penetration tests, which were conducted with specimens assembled similar to the real application of the damping concrete footings. The transferability of the material model to a real accident scenario was verified by a drop test with a full-scale cask on a damping concrete footing. T2 - ASME 2017 Pressure Vessels & Piping Conference (PVP2017) CY - Waikoloa, Hawaii, USA DA - 16.07.2017 KW - Drop test KW - Damping concrete KW - Cask KW - Material model PY - 2017 SN - 978-0-7918-5802-8 VL - 7 SP - Article UNSP V007T07A034, 1 EP - 6 PB - The American Society of Mechanical Engineers CY - New York AN - OPUS4-44042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -