Effects of Zn and Mg Segregations on the Grain Boundary Sliding and Cohesion in Al: Ab Initio Modeling

Kuznetsov, AndreyRAS, Ural Branch, Inst Met Phys, Ekaterinburg 620108, Russia. (author)

Effects of Zn and Mg Segregations on the Grain Boundary Sliding and Cohesion in Al : Ab Initio Modeling

QC 20210507
The formation of Zn and Mg segregations at a tilt sigma 5{013} grain boundary (GB) in Al and the effects of these solutes on deformation behavior of polycrystalline Al were investigated using ab initio total energy calculations. Using a step-by-step modeling of the segregation process, we found that the formation of a thick segregation layer of Zn at the GB is energetically preferable, while the formation of an atomically thin segregation layer is expected in the case of Mg. To reveal the effect of segregation on the cohesive properties of Al GBs, we calculated the energy of cleavage decohesion and the shear resistance for GB sliding. We show that the segregation of Zn results in a substantial decrease in barriers for GB sliding, while the segregation of Mg increases the barriers. The results obtained allow us to explain experimental findings and demonstrate a strong relationship between chemical bonding of solute atoms, their segregation ability, and GB strength.

Karkina, LidiaRAS, Ural Branch, Inst Met Phys, Ekaterinburg 620108, Russia. (author)
Gornostyrev, YuriRAS, Ural Branch, Inst Met Phys, Ekaterinburg 620108, Russia. (author)
Korzhavyi, Pavel A.,1966-KTH,Egenskaper(Swepub:kth)u17nfa0i (author)
RAS, Ural Branch, Inst Met Phys, Ekaterinburg 620108, Russia.Egenskaper (creator_code:org_t)

By the author/editor: Kuznetsov, Andre ...; Karkina, Lidia; Gornostyrev, Yur ...; Korzhavyi, Pavel ...

About the subject

NATURAL SCIENCES: NATURAL SCIENCES; and Physical Science ...; and Condensed Matter ...

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