Dresden 2017 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 34: Poster session II
MM 34.9: Poster
Dienstag, 21. März 2017, 18:30–20:30, P4
Ab initio study of planar defects in Ni and Co based superalloys — •Aparna P. A. Subramanyam, Thomas Hammerschmidt, and Ralf Drautz — ICAMS, Ruhr University-Bochum, Bochum, Germany
Single-crystal Ni-based and Co-based superalloys are used in high temperature applications in land-based turbines and jet engines. These alloys exhibit resistance to deformation at high temperatures due to precipitates of L12-Ni3Al type. One important deformation mechanism of plastic deformation is dislocation shearing of the precipitates by the formation of planar defects.
In this study, we investigate the structural stability of superlattice intrinsic and extrinsic stacking faults (SISF, SESF), anti-phase boundaries and complex stacking faults in the L12 phase of Ni3Al and (Co/Ni)3Al using density functional theory calculations. The segregation of alloying elements to the stacking faults is analysed for the technologically important alloying elements Re, W and Cr. These results are compared to the segregation to twin boundaries in Ni3Al and Co3(Al/W).