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Boareto J.C.,Federal University of Santa Catarina | Metasch R.,TU Dresden | Roellig M.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren | Wendhausen P.A.P.,Federal University of Santa Catarina | Wolter K.J.,TU Dresden
Electronics System Integration Technology Conference, ESTC 2010 - Proceedings | Year: 2010

This work aims to investigate the influence of the element In content on the microstructure and creep properties of Sn-Ag-In solder alloys. For that, four different alloy compositions consisting of a base alloy SnAg3.5 and the addition of 0, 2, 4 and 8 wt% of indium were studied. Those alloys were tested concerning melting and recrystallization temperatures, creep resistance and microstructures. For the creep tests, bulk tensile specimens were used. The creep experiments were performed under different temperatures and stresses. The results were fitted according to the Sinh-Law. Microstructural investigation showed the refinement of microstructure and the formation of different intermetallic compounds in the presence of higher indium contents. Creep measurements have shown that there is a tendency of increasing creep resistance as the indium content is increased. The Sinh-Law describes the alloys creep behaviour properly and the influence of indium content on the constants Q, n, B and A was established. Activation energy for creep (Q) increases with indium content, while the stress exponent (n) decreases. Source

Metasch R.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren | Rodrigues G.,Federal University of Santa Catarina | Roellig M.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren | Wendhausen P.A.P.,Federal University of Santa Catarina | Wolter K.-J.,TU Dresden
2011 12th Int. Conf. on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2011 | Year: 2011

This paper presents a comparison of fatigue experiments with the SnAg3.5 alloy tested with different methods under a constant temperature of 75°C. Cyclic constant rate experiments with constant strain rates of ±1E-3 1/s were used to determine Coffin-Manson parameters. Furthermore the constant rate behaviour was also compared with slower strain rates, with combined relaxation experiments and constant force experiments. © 2011 IEEE. Source

Ortwein A.,Deutsches Biomasseforschungszentrum Gemeinnutzige GmbH | Ortwein A.,TU Bergakademie Freiberg | Zeuner A.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren | Jentsch T.,Helmholtz Center Dresden | And 4 more authors.
International Journal of Hydrogen Energy | Year: 2014

High-Pressure Partial Oxidation is a key technology for the usage of flare gases and heavy oil residues. At the test plant of TU Bergakademie Freiberg, it is possible to gasify different gaseous and liquid fuels at pressures up to 100 bar (g). Information on residence time distributions can be gained by using radioactive tracers. The results of measurements for different reactor geometries and feedstocks will be discussed in this paper. Results of radioactive residence time measurements depend strongly on reactor geometry and require different evaluation methods. Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Source

Opitz J.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren | Mkandawire M.,TU Dresden | Sorge M.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren | Rose N.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren | And 8 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

Various nanoparticles play a prominent role in modern biosciences and medicine. Especially fluorescent cellular biomarkers are a prospective material for diagnostics and therapy. Nevertheless, most of the available biomarkers have some drawbacks due to either physical and optical or cytotoxic properties. Here we investigated the potential of green fluorescent nanodiamonds as extra-and intracellular biomarkers for living cells. We characterized the structure of the used detonation synthesized nanodiamonds (DND) by X-ray diffraction (XRD) and the optical properties by fluorescence and infrared spectroscopy. For the extracellular attachment the nanodiamonds were functionalized by attaching antibodies that target extracellular structures such as membrane. Transfections were mediated by dendrimers, cationic liposomes and protamine sulfate. Using fluorescence microscopy, we confirmed successful extracellular binding on and transfection of the nanodiamonds into prostate cancer cells. Furthermore, nanodiamonds can be targeted selectively to intracellular structures. Therefore, nanodiamonds are a promising tool for biosensing. © 2010 SPIE. Source

Schubert L.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren | Lieske U.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren | Kohler B.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren | Frankenstein B.,Fraunhofer Institute For Zerstorungsfreie Prufverfahren
18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale | Year: 2010

This work investigates the interaction of guided waves with low-velocity impact damage in carbon fibre reinforced plastics (CFRPwhich are widely used in aerospace applications. The interaction of guided-waves with impact induced damage was already shown visually [2,3,4,5], but the quantification of measured time delays and changes in signal-Amplitudes are still challenging. Piezoceramic fibre transducers have been selected for the generation of fundamental symmetric S0 and anti-symmetric A0 Lamb waves with different bandwidth in composite plates. The surface displacement was measured by 3D laser scanning vibrometry. The scanning in the undamaged and damaged state allows the determination of changes in the in-And out-of-plane displacement components of the incident waves. So changes in the amplitude and time shifts of the transmitted waves (S0, A0 mode converted (A0mand scattered waves (A0rcan be evaluated. The A0 mode shows the strongest interaction with impact damage and is further addressed in this paper. Time delays caused by impact damage are shown by cross correlation and a damage indicator is derived. Compression after impact tests were performed to find a quantitative parameter of the received phase change in Lamb wave propagation caused by damaged interaction that correlates with the damaged area of an impacted CFRP. Source

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