|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Deformation and Damage Mechanisms in High Temperature Ni, Co and Fe-based Superalloys
||E-18: Atomistic Modeling of Segregation and Diffusion in Ni-based Superalloys
||You Rao, Maryam Ghazisaeidi
|On-Site Speaker (Planned)
We systematically perform DFT calculations to study the segregation behavior of common alloying elements to stable planar faults in gamma'-Ni3Al. No obvious driving force for segregation to existing SISF, SESF or twin boundaries is found whereas segregation to these faults has been observed in experiments. This discrepancy is an indicator that these stacking faults do not form directly in the -Ni3Al. Instead, their formations involve precursors that are attractive to solutes. Further investigation of the segregation propensity to the meta-stable transitional configurations confirms that the formation mechanisms are related to the concept of reordering instead of simply shearing of superpartials. The change of electronic structures is the major reason for segregation. To obtain the rate of the reordering process, we also study the diffusion mechanisms and calculate the overall diffusion coefficient in this binary compound.
||Planned: Supplemental Proceedings volume