On the relationship between anisotropic yield strength and internal stresses in single crystal superalloys
- The present work focuses on the cubic slip phenomenon in single crystal superalloys with a high fraction of γ' precipitates at high temperature.
The macroscopically apparent cubic slip mechanism is known to significantly reduce the tensile and creep strength of <1 1 1> oriented specimens. However, recent results obtained by 3D dislocation dynamics (Vattré et al., 2009) suggest a new interpretation of the so-called pseudo-cubic slip related to the nature of the dislocation network formation at the interfaces. These results are taken into account in a micromechanical model to improve the estimation of the strain hardening anisotropy. In accordance with the discrete simulations, it is shown that a key role is played by the combination of the activated octahedral slip systems as a function of the crystal orientation. In the <1 1 1> case, the contribution of the activated systems to kinematical hardening compensate, whereas strain hardening remains high for the <0 0 1> case. TheThe present work focuses on the cubic slip phenomenon in single crystal superalloys with a high fraction of γ' precipitates at high temperature.
The macroscopically apparent cubic slip mechanism is known to significantly reduce the tensile and creep strength of <1 1 1> oriented specimens. However, recent results obtained by 3D dislocation dynamics (Vattré et al., 2009) suggest a new interpretation of the so-called pseudo-cubic slip related to the nature of the dislocation network formation at the interfaces. These results are taken into account in a micromechanical model to improve the estimation of the strain hardening anisotropy. In accordance with the discrete simulations, it is shown that a key role is played by the combination of the activated octahedral slip systems as a function of the crystal orientation. In the <1 1 1> case, the contribution of the activated systems to kinematical hardening compensate, whereas strain hardening remains high for the <0 0 1> case. The experimental dependence of plastic flow on the orientation is also explained at the dislocation-scale mechanisms.
Results are presented for the alloy CMSX-4 in several orientations.…
MetadatenAutor*innen: | A. Vattré, Bernard FedelichORCiD |
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Dokumenttyp: | Zeitschriftenartikel |
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Veröffentlichungsform: | Verlagsliteratur |
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Sprache: | Englisch |
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Titel des übergeordneten Werkes (Englisch): | Mechanics of materials |
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Jahr der Erstveröffentlichung: | 2011 |
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Verlag: | Elsevier |
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Verlagsort: | Amsterdam |
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Jahrgang/Band: | 43 |
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Ausgabe/Heft: | 12 |
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Erste Seite: | 930 |
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Letzte Seite: | 951 |
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Freie Schlagwörter: | High-temperature deformation; Micromechanical modeling; Nickel-base superalloys; Strengthening mechanisms |
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DOI: | 10.1016/j.mechmat.2011.07.007 |
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ISSN: | 0167-6636 |
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ISSN: | 1872-7743 |
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Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
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Datum der Freischaltung: | 19.02.2016 |
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Referierte Publikation: | Ja |
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Datum der Eintragung als referierte Publikation: | 05.12.2011 |
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