Transmission electron microscopy study of the microstructural evolution during high-temperature and low-stress (011) [01-1] shear creep deformation of the superalloy single crystal LEK 94
- The present work describes the shear creep behavior of the superalloy LEK 94 at temperatures between 980 and 1050 °C and shear stresses between 50 and 140 MPa for loading on the macroscopic crystallographic shear system (MCSS) (011)[01-1]. The strain rate versus strain curves show short primary and extended secondary creep regimes. We find an apparent activation energy for creep of Qapp = 466 kJ/mol and a Norton-law stress exponent of n = 6. With scanning transmission electron microscopy, we characterize three material states that differ in temperature, applied stress, and accumulated strain/time. Rafting develops perpendicular to the maximum principal stress direction, gamma channels fill with dislocations, superdislocations cut gamma' particles, and dislocation networks form at gamma/gamma' interfaces. Our findings are in agreement with previous results for high-temperature and low-stress [001] and [110] tensile creep testing, and for shear creep testing of the superalloys CMSX-4 andThe present work describes the shear creep behavior of the superalloy LEK 94 at temperatures between 980 and 1050 °C and shear stresses between 50 and 140 MPa for loading on the macroscopic crystallographic shear system (MCSS) (011)[01-1]. The strain rate versus strain curves show short primary and extended secondary creep regimes. We find an apparent activation energy for creep of Qapp = 466 kJ/mol and a Norton-law stress exponent of n = 6. With scanning transmission electron microscopy, we characterize three material states that differ in temperature, applied stress, and accumulated strain/time. Rafting develops perpendicular to the maximum principal stress direction, gamma channels fill with dislocations, superdislocations cut gamma' particles, and dislocation networks form at gamma/gamma' interfaces. Our findings are in agreement with previous results for high-temperature and low-stress [001] and [110] tensile creep testing, and for shear creep testing of the superalloys CMSX-4 and CMSX-6 on the MCSSs (111)[01-1] and (001)[100]. The parameters that characterize the evolving gamma/gamma' microstructure and the evolving dislocation substructures depend on creep temperature, stress, strain, and time.…
Autor*innen: | Leonardo Agudo JácomeORCiD, G. Göbenli, G. Eggeler |
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Persönliche Herausgeber*innen: | M. Göken |
Dokumenttyp: | Zeitschriftenartikel |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | Journal of Materials Research |
Jahr der Erstveröffentlichung: | 2017 |
Herausgeber (Institution): | Materials Research Society |
Verlag: | Cambridge University Press |
Verlagsort: | Cambrigde |
Jahrgang/Band: | 32 |
Ausgabe/Heft: | 24 |
Erste Seite: | 4491 |
Letzte Seite: | 4502 |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
Freie Schlagwörter: | Creep; Dislocations; Microstructure; Scanning transmission electron microscopy (STEM); Shear test |
DOI: | 10.1557/jmr.2017.336 |
ISSN: | 0884-2914 |
ISSN: | 2044-5326 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 12.01.2018 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 12.01.2018 |