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Title: Cohesion enhancing effect of magnesium in aluminum grain boundary: A first-principles determination

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4725512· OSTI ID:22025582
;  [1];  [2];  [1]
  1. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States)
  2. Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States)

The effect of magnesium on grain boundary cohesion in aluminum was investigated by means of first-principles calculations using the Rice-Wang model [Rice and Wang, Mater. Sci. Eng. A 107, 23 (1989)]. It is demonstrated that magnesium is a cohesion enhancer with a potency of -0.11 eV/atom. It is further determined through electronic structure and bonding character analysis that the cohesion enhancing property of magnesium is due to a charge transfer mechanism which is unusually strong and overcomes the negative result of the size effect mechanism. Consistent with experimental results, this work clarifies the controversy and establishes that Mg segregation does not contribute to stress corrosion cracking in Al alloys.

OSTI ID:
22025582
Journal Information:
Applied Physics Letters, Vol. 100, Issue 23; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English