Elemental segregation to antiphase boundaries in a crept CoNi-based single crystal superalloy

Makineni, S.K. and Lenz, M. and Neumeier, S. and Spiecker, E. and Raabe, D. and Gault, B.

Volume: 157 Pages: 62-66
DOI: 10.1016/j.scriptamat.2018.07.042
Published: 2018

We report on the full three-dimensional compositional partitioning among the features of a planar imperfection comprising a superlattice intrinsic stacking fault (SISF) with its leading and trailing partials, as well as the antiphase boundary (APB) in the wake of the trailing partial formed in the L12-ordered γ′ phase of a CoNi-based single crystal superalloy. The partial dislocations and the APB are found to be Cr/Co rich relative to the surrounding γ′ and richer in W/Ta/Ti compared to the γ matrix phase. Solute diffusion mechanisms are derived from the compositional gradients in the vicinity of the imperfection. © 2018 Acta Materialia Inc.

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