Grain Boundary Sink Strength in Anisotropic Materials

Abstract

The grain boundary sink strengths for intrinsic point defects in an anisotropic lattice are calculated.It is shown that the sink strength depends on the grain size, its shape, its metallurgical state, and, for hexagonal symmetry, on the anisotropy factor for the diffusivity (DJD.). It appears to be independent of the volume averaged diffusivity constant. For the grain shape dependence, the Holt and Ibrahim anisotropy factor is obtained only as a limit case.Die Starke der Korngrenzensenke fur Eigen-Punktdefekte in einem anisotropen Gitter wird berechnet. Es wird gezeigt, daB die Senkenstarke von der KorngroBe, deren Form, metallurgischer Zustand und fur hexagonale Symmetrie, vom Anisotropiefaktor fur das Diffusionsvermogen (D,D,) abhangt. Sie scheint von der volurnengemittelten Diffusionskonstante unabhangig zu sein. Fur die Abhangigkeit der Kornform wird der Anisotropiefaktor nach Holt und Ibrahim nur als Grenzfall erhalten. 37*

Radiation tolerance of La-doped nanocrystalline steel under heavy-ion irradiation at different temperatures

“…Grain boundaries, working as sinks, provide sites for point defect recombination, and emit interstitials by a 'loading-unloading' mechanism to annihilate residue vacancies in the grains [27]. For a material with spherical grains, the grain boundary's sink strength is given by [28]…”