TY - CONF A1 - Agudo Jácome, Leonardo A1 - Dlouhý, Antonin T1 - Practical Aspects of 3D Crystalline Defect Analysis for Engineering Materials using Scanning Transmission Electron Microscopy T2 - Microscopy Conference 2013 CY - Regensburg, Germany DA - 2013-08-25 PY - 2013 AN - OPUS4-30211 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Agudo Jácome, Leonardo A1 - Nörtershäuser, P. A1 - Somsen, C. A1 - Dlouhý, A. A1 - Eggeler, G. T1 - On the nature of gamma' phase cutting and its effect on high temperature and low stress creep anisotropy of Ni-base single crystal superalloys N2 - The creep anisotropy of the single crystal superalloy LEK 94 deformed in tension along [0 0 1] and [1 1 0] directions at 1293 K and 160 MPa was investigated. Elementary microstructural processes which are responsible for a higher increase in creep rates with strain during [1 1 0] as compared to [0 0 1] tensile loading were identified. [1 1 0] tensile creep is associated with a higher number of γ' phase cutting events, where two dislocations with equal Burgers vectors of type <1 1 0> jointly shear the γ' phase. The resulting <2 2 0>-type superdislocation can move by glide. In contrast, during [0 0 1] tensile loading, two dislocations with different <1 1 0>-type Burgers vectors must combine for γ' phase cutting. The resulting <2 0 0>-type superdislocations can only move by a combination of glide and climb. The evolution of dislocation networks during creep determines the nature of the γ' phase cutting events. The higher [1 1 0] creep rates at strains exceeding 2% result from a combination of a higher number of cutting events (density of mobile dislocations in γ') and a higher superdislocation mobility (<2 2 0> glide) in the γ' phase. KW - Ni-base single crystal superalloys KW - Creep KW - Anisotropy KW - Dislocation KW - Rafting PY - 2014 DO - https://doi.org/10.1016/j.actamat.2014.01.021 SN - 1359-6454 SN - 1873-2453 VL - 69 SP - 246 EP - 264 PB - Elsevier Science CY - Kidlington AN - OPUS4-30387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Payton, E. J. A1 - Agudo Jácome, Leonardo A1 - Nolze, Gert T1 - Phase Identification by Image Processing of EBSD Patterns N2 - Automated electron backscatter diffraction (EBSD) is generally unable to distinguish between multiple cubic phases in a specimen without additional information, such as that obtained by simultaneous energy dispersive X-ray spectroscopy (EDS). Small particles of phases with relatively similar compositions push the limits of phase identification using simultaneous EBSD and EDS, and a mismatch exists between the spatial resolutions of these two techniques due to them having different electron interaction volumes. In a recent paper, the present authors explored using backscatter detectors mounted on top of the EBSD detector to obtain atomic number (Z) contrast images that could be used for phase segmentation in cases where the results from the EBSD and EDS signals remain ambiguous. In the present work, we show that similar information can be obtained from the raw EBSD patterns themselves at higher spatial resolution than was obtained from the backscatter detectors, with the additional advantage of having no spatial mismatch between the data collection grids. KW - Phase identification KW - Backscattered electrons KW - EBSD KW - SEM PY - 2013 DO - https://doi.org/10.1017/S143192761300620X VL - 19 IS - Suppl. 2 SP - 842 EP - 843 AN - OPUS4-37985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo A1 - Göbenli, Gülcan A1 - Eggeler, Gunther T1 - High Temperature and Low Stress (011)<01-1> Shear Creep Deformation of the Single Crystal Ni-Based Superalloy LEK 94 - elementary softening and deformation processes T2 - 17th International Conference on the Strength of Materials (ICSMA17) CY - Brno, Czech Republic DA - 2015-10-01 PY - 2015 AN - OPUS4-34516 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo A1 - Eggeler, Gunther A1 - Pöthkow, Kai A1 - Pätsch, Olaf A1 - Hege, H. C. T1 - Three-Dimensional Characterization of Superdislocation Interactions in the High Temperture and Low Stress Creep Regime of Ni-Base Superalloy Single Crystals T2 - 13th International Conference on Creep and Fracture of Engineering Materials and Structures (CREEP 2015) CY - Toulouse, France DA - 2015-05-31 PY - 2015 AN - OPUS4-34517 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo T1 - Diffraction Contrast in Scanning Transmission Electron Microscopy (STEM) as a Powerful Tool for Quantitative Dislocation Analysis T2 - Institutskolloquium, Institut für Materialphysik der westfälischen Wilhelms-Universität Münster CY - Münster, Germany DA - 2014-06-24 PY - 2014 AN - OPUS4-32949 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo T1 - Diffraction Contrast in Scanning Transmission Electron Microscopy (STEM) as a Powerful Tool for Quantitative Dislocation Analysis T2 - Symposium "Recent prograss in transmission electron microscopy and atom probe analysis of advanced high temperatur materials" vom SFB/TR 103 CY - Bochum, Germany DA - 2014-03-06 PY - 2014 AN - OPUS4-32950 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo A1 - Dlouhý, Antonin A1 - Otto, Frederik A1 - Somsen, Christoph A1 - George, Easo P. A1 - Eggeler, Gunther T1 - Structural Defects in Advanced Alloys and Intermetallics T2 - Microscopy Conference (MC) 2013 CY - Regensburg, Germany DA - 2013-08-25 PY - 2013 AN - OPUS4-32951 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo A1 - Dlouhý, Antonin A1 - Otto, Frederik A1 - Somsen, Christoph A1 - George, Easo P. A1 - Eggeler, Gunther T1 - Structural Defects in Advanced Alloys and Intermetallics T2 - DGM-Arbeitskreis (AK) Mechanisches Werkstoffverhalten bei hoher Temperatur CY - Mülheim an der Ruhr, Germany DA - 2013-10-09 PY - 2013 AN - OPUS4-32952 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo A1 - Mosquera Feijoo, Maria A1 - Nolze, Gert A1 - Rizzo, F. ED - Militzer, M. ED - Botton, G. ED - Chen, L.-Q. ED - Howe, J. ED - Sinclair, C. ED - Zurob, H. T1 - Nano-sized precipitates in an Fe-13Cr alloy formed under oxidizing water vapor atmosphere N2 - Oxidation of a Fe –13Cr alloy under water vapor at 600°C produced a zone of nano-sized precipitation underneath the outside scale formed by iron oxides and Fe–Cr spinel. The majority of the spinel layer shows a fixed orientation relationship to the ferritic matrix: {1 0 0}α || {1 0 0}sp & <0 1 1>α || <0 0 1>sp . However, also the discovered precipitated particles are characterized by the same crystallographic orientation relationship to the respective ferritic parent grain. The habit of the precipitates is best described by a lath morphology with their main axis parallel to <1 0 0> of ferrite. Energy dispersive X-ray spectroscopy (EDX) and electron backscatter diffraction (EBSD) in scanning electron microscope (SEM) have been applied to characterize the oxide layer in micrometer scale. The clearly smaller precipitates were subsequently investigated by transmission electron microscopy (TEM). Specimens have been prepared by focused ion-beam (FIB) milling at an area previously characterized by EBSD. They cover the ferritic base material, but mainly the precipitation zone and the Fe–Cr spinel layer. Energy filtered selected area diffraction (SAD) in the conventional (C)TEM and high-angle annular dark field (HAADF) imaging in the scanning (S)TEM mode were employed in the characterization of the specimens. T2 - PTM 2015 - International conference on solid-solid phase transformations in inorganic materials CY - Whistler, BC, Canada DA - 28.06.2015 KW - Precipitation KW - Nano-crystals KW - Oxidation KW - Phase transformation KW - EBSD KW - TEM PY - 2015 SP - 379 EP - 386 AN - OPUS4-34444 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -