TY - CONF A1 - Lohrer, Christian T1 - Current topics and challenges in the forum of notified bodies N2 - Es werden aktuelle Herausforderungen und Problemfälle im Forum der benannten Stellen für pyrotechnische Gegenstände nach der Richtlinie 2013/29/EU vorgestellt. Diese betrift maßgeblich: Wechsel der benannten Stellen, RRT, Kennzeichnung, Feuerwerksraketen, Transport, Konditionierung, Fehler, Module, Raucheffekte, Losprüfungen. N2 - Current challenges and problems in the forum of notified bodies under the Directive 2013/29/EU are presented. This mainly comprises of: change of notified bodies, labelling, fireworks rockets, transport, conditioning, nonconformities, modules smoke effects and batch testing. T2 - 16th Meeting of the AdCo Pyrotechnic Articles CY - Leuven, Belgium DA - 03.03.2020 KW - Batch testing KW - Pyrotechnics KW - Nonconformities PY - 2020 AN - OPUS4-50513 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klinger, Christian T1 - Failure analysis on medical implants N2 - The application of implants e.g. for osteosynthesis or substitution of worn out joints is common practice since decades. Successes in surgery and orthopedics are highly dependent on the use of artificial parts for implanting into the human body. Over the years the number of surgical procedures and the number of different implants were growing rapidly. Implants, however, are exposed to complex mechanical, corrosive and tribological loads along with restriction in geometric dimension. While being essentially successful, the sheer number of cases leads to a rising number of implant failures. Such failures are painful for the affected patients and are very costly. The failure cases presented in this paper occurred from 1981 to 2016. The predominant failure mechanism of all kinds of implants is fatigue fracture. Fatigue cracks are initiated due to a whole bunch of reasons: Material defects and fabrication defects are rare events. The main factors are cyclic overload due to improper fitting with delayed bone healing, corrosion and unauthorized modification of the implant during surgery T2 - Int. Conf. on Engineering Failure Analysis 2018 CY - Budapest, Hungary DA - 08.07.2018 KW - Implant failures KW - Complex loading KW - Fatigue fracture PY - 2018 AN - OPUS4-50198 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Frenzel, Florian T1 - Spectroscopic study of plasmon enhanced UPCON luminescence of silica-metal core-shell nanocomposites - status report N2 - The presentation focuses on the current state of the optical spectroscopic studies on plasmon enhanced upconversion luminescent processes of silica-metal core-shell nanocomposites. A general introduction of the upconversion process, the theoretical basis of plasmonic enhancement, the theoretical requirements in regard to NP architecture for plasmon enhanced UC will be outlined. The first proof-of-concept measurements show the difficulty in realization the theoretical measurement parameters in laboratory conditions and underline the need for shifting the experiments to single particle level.“ T2 - Gruppenseminar der Nanooptik an der HU Berlin, Prof. Benson, Institut für Physik, Raum 1‘404 CY - Berlin, Germany DA - 09.05.2017 KW - Upconversion KW - Pplasmon enhancement KW - Core-shell nanoparticles KW - Silca-metal nanoparticles PY - 2017 AN - OPUS4-50698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Elabshihy, Karim T1 - Nano-mechanical characterization of epoxy/Cu interphase N2 - Characterization of the mechanical properties of interphases is essential when designing multicomponent materials such as fiber-reinforced matrices, protective coatings or multi-layered structures for integrated circuits. It can provide vital information about the durability of the finished product as a composite because failure is often initiated in the interfacial region induced by internal or external stress during fabrication or service. Nanoindentation is a powerful tool for investigating mechanical properties on the micro/nano scale. However, there are some challenges associated with conducting nanoindentation near interface regions. One main challenge is that the small thickness of the interphase region (typically 1-2µm) makes it difficult to apply several adjacent indents without overlap. Another issue is that the indentations are usually restricted by local reinforcement, and it becomes difficult to isolate the change in mechanical properties due solely to interphase formation. In this study we try to gauge the feasibility of nanoindentation for characterizing epoxy/Cu interphases. We develop a sample preparation method and optimize nanoindentation parameters in an attempt to avoid the restrictions mentioned above. Atomic force microscopy (AFM) and finite element analysis are employed as reference techniques to evaluate the effectiveness of our technique. We show the influence of preparation method and nanoindentaion parameters on measurements of interphase properties and how they relate the mentioned challenges. T2 - Nanobrücken 2016 CY - Saarbrücken, Germany DA - 02.03.2016 KW - Composite KW - Epoxy KW - Interphase KW - Nanoindentation PY - 2016 AN - OPUS4-35496 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leng, Jing T1 - Crystallization behavior of nanocomposites based on Polylactide – Rigid Amorphous Phase due to the Nanofiller N2 - Two kinds of synthesized NiAl (NiAl-LDH) and MgAl (MgAl-LDH) layered double hydroxides were melt blended with commercial polylactide to prepare different polymer based nanocomposites. The MgAl-LDH based nanocomposites and NiAl-LDH based nanocomposites have a diferent but mixed intercalated / exfoliated structure. Based on the different structures, the crystallization behaviors of polymer based nanocomposites were investigated by differential scanning calorimetry (DSC) and temperature modulated differential scanning calorimetry (TMDSC) specificly where the heating and cooling rates were varied in a extrmely wied range. In a first step, the cooling rate where crystallization can be completely surpressed is estimated. In a second step, based on a specified temperature program the crystalline fraction (CF), the rigid amorphous fraction (RAF) and the mobile amorphous fraction (MAF) were calculated from the the enthalpy and specific heat capacity in dependence on the concentration of the nanofiller. The rigid amorphous fraction was considered as resulting from the the crystallites and the nanofiller. For the first time both fractions were calculated quantitatively without any additional assumption. T2 - 80. Jahrestagung der DPG und DPG-Frühjahrstagung CY - Regensburg, Germany DA - 06.03.2016 KW - Polylactide KW - Layered Doubled Hydroxide KW - Rigid Amorphous Physe PY - 2016 AN - OPUS4-35561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Elabshihy, Karim T1 - Investigation of the time-dependent behavior of cnt-filled epoxy using nanoindentation N2 - Epoxy/Carbon nanotube (CNT) composites are interesting materials that could be used in a wide variety of applications. In this study, CNT contents of 0.25, 0.5, 1 and 2 wt% were used for reinforcing epoxy. A nanoindentation device and a temperature regulating system were developed in order to investigate the effect of CNTs on the time-dependent properties of epoxy using relaxations and creep tests on the nano scale. The relaxation tests showed a significant shift for the relaxation spectrum towards shorter times with introducing a low CNT content of 0.25 wt%. Additionally, creep tests showed that both the holding time at a constant load and the unloading velocity have a major effect on the contact stiffness. However, there was no effect for the CNTs on the creep behavior with contents lower than 1 wt%, which was related to the presence of a percolation threshold around this value. T2 - Nanobrücken 2013 CY - Dresden, Germany DA - 20.03.2013 KW - Epoxy KW - CNT KW - Time-dependent KW - Nanoindentation PY - 2013 AN - OPUS4-35533 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madkour, Sherif A1 - Szymoniak, Paulina A1 - Heidari, Mojdeh A1 - von Klitzing, Regine A1 - Schönhals, Andreas T1 - Evidence of a three-layered structure in ultra-thin PVME and PVME/PS blend films by nano-sized relaxation spectroscopy N2 - Despite the many controversial discussions about the nanometric confinement effect and the predictions of the three-layer model, much remain not understood and/or experimentally unproven. Here, a combination of Broadband Dielectric Spectroscopy (BDS), Specific Heat Spectroscopy (SHS), and ellipsometry was utilized to investigate the glassy dynamics of ultra-thin films of Poly (vinyl methyl ether) (PVME) and PVME/Polystyrene (PS) 50:50 wt-% miscible blend (thicknesses: 8nm - 200nm). For BDS measurements, a recently developed nano-structured sample arrangement; where ultra-thin films are spin-coated on an ultra-flat highly conductive silicon wafer and sandwiched between a wafer with nanostructured silica nano-spacers, was used. For PVME films, two processes were observed and interpreted to be the α-processes of a bulk-like layer and an absorbed layer to the substrate. BDS and SHS showed that glassy dynamics are bulk-like. However, for films lower than 15nm, BDS showed weakly slowed dynamics. For PVME/PS blend, by a self-assembling process, a nanometer-thin surface layer with a higher molecular mobility is formed at the polymer/air interface. By measuring the dynamic Tg in dependence on the film thickness, both BDS and SHS, showed that the Tg of the whole film was strongly influenced by that nanometer thick surface layer, with a lower Tg. T2 - 80. Jahrestagung der DPG und DPG-Frühjahrstagung CY - Regensburg DA - 06.03.2016 KW - Ultra-thin films PY - 2016 AN - OPUS4-35540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias T1 - 2015 SRV global circular comparison results bulletin N2 - Tribological profile of hydraulic oils by using SRV. The determination of a set of critical, tribological by using different SRV-based test methods. The SRV-based concept of tribological profile generates the wear volumes on two triboelements (specimen), the extreme pressure properties and friction under different contact pressures. Thus, the benchmark and validation of hydraulic oils bear on a wider range of tribological properties. The RR2016 extends with six hydraulic oils to other base oil types including biodegradable fluids, which were all tested according to ASTM D7043 in order to consolidate the correlation between SRV and V104C. T2 - Working Group Meeting about SRV in China 2016 CY - Beijing, China DA - 05.04.2016 KW - SRV KW - Standards KW - China PY - 2016 AN - OPUS4-35744 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias T1 - 2016 SRV global circular comparison results bulletin N2 - Actions from the meeting in April 2016: 1. Four SAC test methods are in place and were revised: SH/T 0721 (Grease, coefficient of friction and wear), SH/T 0784 (Grease, pass load/O.K. load), SH/T 0847 (Oil, coefficient of friction and wear) and SH/T 0882 released by 11-2014 (Oil, pass load/O.K. load). 2. New test method to evaluate anti-fretting properties of greases based was approved by SAC TC280 and will be released. 3. SAC TC280 accepted the project “Simulation of synchronizer by using SRV”. Draft text to be submitted by 03-2017. Discussions on a parallel ASTM test method. 4. A procedure for “Wear Volume” is under development for SAC TC280. T2 - Working Group Meeting about SRV in China 2016 CY - Beijing, China DA - 05.04.2016 KW - SRV KW - Standards KW - China PY - 2016 AN - OPUS4-35745 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias T1 - Recent work of the global SRV working group and the development trend of SRV standards N2 - „Cliff“-testing by using SRV The identification in engine or gear tests of the induction time or off-set point („cliff“), after which wear and friction increased. “Cliff” testing as auxiliary method supports the interpretation of engine tests, as it enhances the values of expensive engine tests, because it enables correlations between friction & wear, either from engine or in SRV tests, with additive depletion, oxidation, viscometrics and dispersancy/detergency. Oil samples taken in discrete intervals and “Cliff” tested monitors the evolution of tribological and functional properties versus engine running time. “Cliff” testing by using SRV is a purposeful tool in order to secure and accelerate metallurgical developments and the development of lubricant formulations. T2 - Working Group Meeting about SRV in China 2016 CY - Beijing, China DA - 05.04.2016 KW - SRV KW - Standards KW - China PY - 2016 AN - OPUS4-35747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -