Insights into factors that affect non-Arrhenius migration of a simulated incoherent S3 grain boundary

被引：22

作者：

Verma, Akarsh ^{[1
,4
]}

Johnson, Oliver K. ^{[1
]}

Thompson, Gregory B. ^{[2
]}

Chesser, Ian ^{[3
]}

Ogata, Shigenobu ^{[4
]}

Homer, Eric R. ^{[1
]}

机构：

[1] Brigham Young Univ, Dept Mech Engn, Provo, UT 84602 USA

[2] Univ Alabama, Dept Met & Mat Engn, Tuscaloosa, AL USA

[3] Los Alamos Natl Lab, Mat Phys & Applicat Div, Los Alamos, NM USA

[4] Osaka Univ, Grad Sch Engn Sci, Dept Mech Sci & Bioengn, Osaka, Japan

来源：

ACTA MATERIALIA | 2023年 / 258卷

关键词：

Molecular dynamics; Nickel; Grain boundary migration; Interatomic potentials; INTERATOMIC POTENTIALS; MOBILITY; MECHANISMS; COPPER; TEMPERATURE; GROWTH; MOTION; DYNAMICS; KINETICS; METALS;

D O I：

10.1016/j.actamat.2023.119210

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Non-Arrhenius grain boundary migration, sometimes referred to as antithermal migration where temperature and GB velocity values are inversely related to each other, is examined in an incoherent twin & sigma;3 [111] 60 degrees (11 8 5) nickel grain boundary. Molecular dynamics is used to simulate migration and examine the effect of various factors on the migration, including interatomic potential, system size, driving force, and variation of atomic grain boundary structure. A classical model for grain boundary migration, in its unsimplified form, is used to analyze the results. The grain boundaries exhibit migration mechanisms with very low apparent barrier heights to migration. As a result, the boundaries migrate quickly but exhibit a velocity saturation similar to that of dislocations. The various interatomic potentials exhibit different migration velocities, but their similarities suggest they all predict similar overall behaviors of migration. The variation of atomic structure in the same incoherent twin grain boundary leads to diverse behaviors with barrier heights that vary from non-Arrhenius to Arrhenius migration. Facet nucleation is confirmed not to be a requirement for this boundary based on an examination of simulation cell size; however, the presence and/or interaction between numerous facets does suggest a slowing and increased barrier height to migration for larger boundaries.

引用

页数：12

共 70 条

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