TY - CONF A1 - Cabeza, Sandra A1 - Bruno, Giovanni A1 - Mishurova, Tatiana T1 - Characterization of multiphase metal matrix composites by means of CT and neutron diffraction N2 - The present study examines the relationship between the microstructure of multiphase metal matrix composites and their damage mechanisms. The matrix AlSi12CuMgNi was combined with 15% vol. Al₂O₃ (short fibers), and with 7% vol. Al₂O₃ + 15% vol. SiC (short fibers and whiskers, respectively). The experimental approach encompasses 3D microstructure characterization by means of computed tomography of samples (a) as-cast, (b) after heat treatment, and (c) after compression tests at room temperature. The volume fraction of different phases, their distribution, their orientation, and the presence of defects and damage are studied. The influence of the addition of SiC particles on mechanical properties of composite was investigated. Phase-specific load partition analysis for samples with fiber plane parallel to load was performed by using neutron diffraction (ND) during in-situ compression. ND results show damage in the Si phase, while Al₂O₃ short fibers carry load without damage until failure. The computed tomography observations confirm the load partition analysis. T2 - WCNDT CY - München, Germany DA - 13.06.2016 KW - thermal treatment KW - synchrotron CT KW - neutron diffraction KW - composite KW - aluminum KW - residual stress PY - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-365499 AN - OPUS4-36549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Selleng, Christian A1 - Meng, Birgit A1 - Simon, Sebastian T1 - Phasenbestand von hydrothermal behandeltem UHPC N2 - Die Festigkeit von Ultra-Hochleistungsbeton (UHPC) lässt sich durch (hydro-)thermale Behandlung weiter steigern. In der Literatur (zum Beispiel Yazici, 2013) wird diese Festigkeitssteigerung mit der Bildung von Tobermorit, einer kristallinen C-S-H-Phase, in Verbindung gebracht, wie dies auch für Porenbeton oder Kalksilikat-Baustoffe angenommen wird. Die durchgeführten röntgenographische Untersuchungen geben jedoch keinen Hinweis auf das Vorhandensein von Tobermorit, sodass diese Erklärung nicht tragfähig ist. Die tatsächliche Ursachen für die real vorhandene Festigkeitssteigerung bleibt vorerst unklar. T2 - Workshop der DMG-Sektionen CPKM und AMITU CY - Bad Windsheim, Germany DA - 24.02.2016 KW - tobermorite KW - x-ray diffraction KW - ultra-high performance concrete KW - thermal treatment PY - 2016 AN - OPUS4-35381 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -