Quantitative 3D Stereo Microscopy in Diffraction Contrast (S)TEM
- The realistic description of plastic deformation caused by dislocations demands the representative measurement of their features, e.g., Burgers vector, slip plane, line direction and density. In the case of bulk deformation of technical alloys, reliable data must be ensured for large regions. Nonetheless, the (thin) filiform nature of dislocations and also the heterogeneity in some microstructures additionally require flexible analysis techniques that resolve the details of their interactions. Strong and clear channeling contrasts, faint extinction contours and the absence of chromatic aberration make scanning transmission electron microscopy (STEM) an ideal imaging mode in wide and thick regions of TEM foils, as opposed to conventional (C)TEM. It is the purpose of this contribution to show how STEM can be applied for quantitative measurement of dislocation features. Furthermore, a new tool will be presented, which enables the three-dimensional (3D) reconstruction, visualization andThe realistic description of plastic deformation caused by dislocations demands the representative measurement of their features, e.g., Burgers vector, slip plane, line direction and density. In the case of bulk deformation of technical alloys, reliable data must be ensured for large regions. Nonetheless, the (thin) filiform nature of dislocations and also the heterogeneity in some microstructures additionally require flexible analysis techniques that resolve the details of their interactions. Strong and clear channeling contrasts, faint extinction contours and the absence of chromatic aberration make scanning transmission electron microscopy (STEM) an ideal imaging mode in wide and thick regions of TEM foils, as opposed to conventional (C)TEM. It is the purpose of this contribution to show how STEM can be applied for quantitative measurement of dislocation features. Furthermore, a new tool will be presented, which enables the three-dimensional (3D) reconstruction, visualization and quantification of dislocation densities and directions from stereo-pairs. The application of these techniques will be shown on a monocrystalline Ni-base superalloy, an important class of structural materials that has been implemented in the first row blades of gas turbines. The examples are extracted from specimens subjected to creep deformation at high temperature and low stress under various macroscopic deformation geometries. The spacial and angular accuracy are discussed as well as possible sources of error.…
Autor*innen: | Leonardo Agudo JácomeORCiD |
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Dokumenttyp: | Vortrag |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2017 |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Freie Schlagwörter: | 3D reconstruction; Dislocation; Microscopy; Scanning Transmission Electron Microscopy |
Veranstaltung: | Symposium on Advanced Mechanical and Microstructural Characterization Methods for SX Ni- and Co-based Superalloys |
Veranstaltungsort: | Bochum, Germany |
Beginndatum der Veranstaltung: | 13.09.2017 |
Enddatum der Veranstaltung: | 14.09.2017 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 27.09.2017 |
Referierte Publikation: | Nein |
Eingeladener Vortrag: | Nein |