TY - JOUR

T1 - Grain boundary segregation in Ni-base alloys: A combined atom probe tomography and first principles study

AU - Ebner, Anna

AU - Jakob, Severin

AU - Clemens, Helmut

AU - Pippan, Reinhard

AU - Maier-Kiener, Verena

AU - He, Shuang

AU - Ecker, Werner

AU - Scheiber, Daniel

AU - Razumovskiy, V.I.

N1 - Publisher Copyright: © 2021 The Authors

PY - 2021/12

Y1 - 2021/12

N2 - Grain boundary engineering (GBE) plays an important role in the design of new polycrystalline materials with enhanced mechanical properties. This approach has been shown to be very effective in design of Ni-base alloys, where grain boundary segregation is expected to play a central role in defining their mechanical behavior. In the present work, we apply a powerful combination of advanced experimental and theoretical methods to reveal the grain boundary chemistry of the 725 Ni-base alloy at the atomic level. The methods of investigation comprise atom probe tomography (APT) measurements and density functional theory (DFT) calculations. We also propose a way to cross-validate DFT and APT results in a DFT-based model approach for evaluation of the interfacial excess as a function of the heat treatment history of the material and its chemistry. Both theoretical and experimental methods are applied to a detailed analysis of the GB chemistry of three modifications of the 725 alloy and the results of this investigation are presented and discussed in detail.

AB - Grain boundary engineering (GBE) plays an important role in the design of new polycrystalline materials with enhanced mechanical properties. This approach has been shown to be very effective in design of Ni-base alloys, where grain boundary segregation is expected to play a central role in defining their mechanical behavior. In the present work, we apply a powerful combination of advanced experimental and theoretical methods to reveal the grain boundary chemistry of the 725 Ni-base alloy at the atomic level. The methods of investigation comprise atom probe tomography (APT) measurements and density functional theory (DFT) calculations. We also propose a way to cross-validate DFT and APT results in a DFT-based model approach for evaluation of the interfacial excess as a function of the heat treatment history of the material and its chemistry. Both theoretical and experimental methods are applied to a detailed analysis of the GB chemistry of three modifications of the 725 alloy and the results of this investigation are presented and discussed in detail.

UR - http://www.scopus.com/inward/record.url?scp=85116704139&partnerID=8YFLogxK

U2 - 10.1016/j.actamat.2021.117354

DO - 10.1016/j.actamat.2021.117354

M3 - Article

VL - 221.2021

JO - Acta materialia

JF - Acta materialia

SN - 1359-6454

IS - December

M1 - 117354

ER -