TY  - JOUR
A1  - Müller, B. R.
A1  - Cooper, R. C.
A1  - Lange, A.
A1  - Kupsch, Andreas
A1  - Wheeler, M.
A1  - Hentschel, M. P.
A1  - Staude, A.
A1  - Pandey, A.
A1  - Shyam, A.
A1  - Bruno, Giovanni
T1  - Stress-induced microcrack density evolution in beta-eucryptite ceramics
BT  - experimental observations and possible route to strain hardening
JF  - Acta materialia
N2  - In order to investigate their microcracking behaviour, the microstructures of several beta-eucryptite ceramics, obtained from glass precursor and cerammed to yield different grain sizes and microcrack densities, were characterized by laboratory and synchrotron x-ray refraction and tomography. Results were compared with those obtained from scanning electron microscopy (SEM). In SEM images, the characterized materials appeared fully dense but computed tomography showed the presence of pore clusters. Uniaxial tensile testing was performed on specimens while strain maps were recorded and analyzed by Digital Image Correlation (DIC). X-ray refraction techniques were applied on specimens before and after tensile testing to measure the amount of the internal specific surface (i.e., area per unit volume). X-ray refraction revealed that (a) the small grain size (SGS) material contained a large specific surface, originating from the grain boundaries and the interfaces of TiO2 precipitates; (b) the medium (MGS) and large grain size (LGS) materials possessed higher amounts of specific surface compared to SGS material due to microcracks, which decreased after tensile loading; (c) the precursor glass had negligible internal surface. The unexpected decrease in the internal surface of MGS and LGS after tensile testing is explained by the presence of compressive regions in the DIC strain maps and further by theoretical arguments. It is suggested that while some microcracks merge via propagation, more close mechanically, thereby explaining the observed X-ray refraction results. The mechanisms proposed would allow the development of a strain hardening route in ceramics.
KW  - Beta-eucryptite
KW  - Microcracked ceramics
KW  - X-ray refraction
KW  - Tensile load
KW  - Strain hardening
Y1  - 2017
U6  - https://doi.org/10.1016/j.actamat.2017.10.030
SN  - 1359-6454
SN  - 1873-2453
VL  - 144
SP  - 627
EP  - 641
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Nellesen, Jens
A1  - Laquai, R.
A1  - Müller, B. R.
A1  - Kupsch, Andreas
A1  - Hentschel, M. P.
A1  - Anar, N. B.
A1  - Soppa, E.
A1  - Tillmann, W.
A1  - Bruno, Giovanni
T1  - In situ analysis of damage evolution in an Al/ Al2O3 MMC under tensile load by synchrotron X-ray refraction imaging
JF  - Journal of materials science
N2  - The in situ analysis of the damage evolution in a metal matrix composite (MMC) using synchrotron X-ray refraction radiography (SXRR) is presented. The investigated material is an Al alloy (6061)/10 vol MMC after T6 heat treatment. In an interrupted tensile test the gauge section of dog bone-shaped specimens is imaged in different states of tensile loading. On the basis of the SXRR images, the relative change of the specific surface (proportional to the amount of damage) in the course of tensile loading was analyzed. It could be shown that the damage can be detected by SXRR already at a stage of tensile loading, in which no observation of damage is possible with radiographic absorption-based imaging methods. Moreover, the quantitative analysis of the SXRR images reveals that the amount of damage increases homogeneously by an average of 25% with respect to the initial state. To corroborate the experimental findings, the damage distribution was imaged in 3D after the final tensile loading by synchrotron X-ray refraction computed tomography (SXRCT) and absorption-based synchrotron X-ray computed tomography (SXCT). It could be evidenced that defects and damages cause pronounced indications in the SXRCT images.
Y1  - 2018
U6  - https://doi.org/10.1007/s10853-017-1957-x
SN  - 0022-2461
SN  - 1573-4803
VL  - 53
IS  - 8
SP  - 6021
EP  - 6032
PB  - Springer
CY  - New York
ER  - 
TY  - CHAP
A1  - Kurbel, Karl
A1  - Nowak, Dawid
A1  - Azodi, Amir
A1  - Jaeger, David
A1  - Meinel, Christoph
A1  - Cheng, Feng
A1  - Sapegin, Andrey
A1  - Gawron, Marian
A1  - Morelli, Frank
A1  - Stahl, Lukas
A1  - Kerl, Stefan
A1  - Janz, Mariska
A1  - Hadaya, Abdulmasih
A1  - Ivanov, Ivaylo
A1  - Wiese, Lena
A1  - Neves, Mariana
A1  - Schapranow, Matthieu-Patrick
A1  - Fähnrich, Cindy
A1  - Feinbube, Frank
A1  - Eberhardt, Felix
A1  - Hagen, Wieland
A1  - Plauth, Max
A1  - Herscheid, Lena
A1  - Polze, Andreas
A1  - Barkowsky, Matthias
A1  - Dinger, Henriette
A1  - Faber, Lukas
A1  - Montenegro, Felix
A1  - Czachórski, Tadeusz
A1  - Nycz, Monika
A1  - Nycz, Tomasz
A1  - Baader, Galina
A1  - Besner, Veronika
A1  - Hecht, Sonja
A1  - Schermann, Michael
A1  - Krcmar, Helmut
A1  - Wiradarma, Timur Pratama
A1  - Hentschel, Christian
A1  - Sack, Harald
A1  - Abramowicz, Witold
A1  - Sokolowska, Wioletta
A1  - Hossa, Tymoteusz
A1  - Opalka, Jakub
A1  - Fabisz, Karol
A1  - Kubaczyk, Mateusz
A1  - Cmil, Milena
A1  - Meng, Tianhui
A1  - Dadashnia, Sharam
A1  - Niesen, Tim
A1  - Fettke, Peter
A1  - Loos, Peter
A1  - Perscheid, Cindy
A1  - Schwarz, Christian
A1  - Schmidt, Christopher
A1  - Scholz, Matthias
A1  - Bock, Nikolai
A1  - Piller, Gunther
A1  - Böhm, Klaus
A1  - Norkus, Oliver
A1  - Clark, Brian
A1  - Friedrich, Björn
A1  - Izadpanah, Babak
A1  - Merkel, Florian
A1  - Schweer, Ilias
A1  - Zimak, Alexander
A1  - Sauer, Jürgen
A1  - Fabian, Benjamin
A1  - Tilch, Georg
A1  - Müller, David
A1  - Plöger, Sabrina
A1  - Friedrich, Christoph M.
A1  - Engels, Christoph
A1  - Amirkhanyan, Aragats
A1  - van der Walt, Estée
A1  - Eloff, J. H. P.
A1  - Scheuermann, Bernd
A1  - Weinknecht, Elisa
ED  - Meinel, Christoph
ED  - Polze, Andreas
ED  - Oswald, Gerhard
ED  - Strotmann, Rolf
ED  - Seibold, Ulrich
ED  - Schulzki, Bernhard
T1  - HPI Future SOC Lab
BT  - Proceedings 2015
N2  - Das Future SOC Lab am HPI ist eine Kooperation des Hasso-Plattner-Instituts mit verschiedenen Industriepartnern. Seine Aufgabe ist die Ermöglichung und Förderung des Austausches zwischen Forschungsgemeinschaft und Industrie.
Am Lab wird interessierten Wissenschaftlern eine Infrastruktur von neuester Hard- und Software kostenfrei für Forschungszwecke zur Verfügung gestellt. Dazu zählen teilweise noch nicht am Markt verfügbare Technologien, die im normalen Hochschulbereich in der Regel nicht zu finanzieren wären, bspw. Server mit bis zu 64 Cores und 2 TB Hauptspeicher. Diese Angebote richten sich insbesondere an Wissenschaftler in den Gebieten Informatik und Wirtschaftsinformatik. Einige der Schwerpunkte sind Cloud Computing, Parallelisierung und In-Memory Technologien. 
In diesem Technischen Bericht werden die Ergebnisse der Forschungsprojekte des Jahres 2015 vorgestellt.  Ausgewählte Projekte stellten ihre Ergebnisse am 15. April 2015 und 4. November 2015 im Rahmen der Future SOC Lab Tag Veranstaltungen vor.
KW  - Future SOC Lab
KW  - Forschungsprojekte
KW  - Multicore Architekturen
KW  - In-Memory Technologie
KW  - Cloud Computing
KW  - maschinelles Lernen
KW  - künstliche Intelligenz
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-102516
ER  -