%0 Journal Article
%T A single grain boundary parameter to characterize normal stress fluctuations in materials with elastic cubic grains
%+ Jozef Stefan Institute [Ljubljana] (IJS)
%+ Laboratoire de Comportement Mécanique des Matériaux Irradiés (LCMI)
%A El Shawish, Samir
%A Mede, Timon
%A Hure, Jeremy
%Z The authors gratefully acknowledge financial support provided by Slovenian Research Agency (grant P2-0026)and French Atomic Energy Commission.
%< avec comité de lecture
%@ 0997-7538
%J European Journal of Mechanics - A/Solids
%I Elsevier
%P 104293
%8 2021
%D 2021
%R 10.1016/j.euromechsol.2021.104293
%K IGSCC
%K grain boundary type
%K coincidence site lattice
%K intergranular normal stress fluctuations
%K finite element method
%K grain boundary engineering
%Z Chemical Sciences/Material chemistryJournal articles
%X A finite element analysis of intergranular normal stresses is performed in order to identify a possible statistical correlationbetween the intergranular normal stresses and the corresponding grain boundary type within a polycrystalline aggregate. Elasticcontinuum grains of cubic lattice symmetry are assumed in the analysis. Meaningful results are obtained by analyzing the first twostatistical moments of grain boundary normal stresses obtained on several grain boundary types.Among the five macroscopic parameters (5D) describing a grain boundary, the orientation of the grain boundary plane relativeto the two adjacent crystal lattices (4D) is found to be the most important property influencing the normal stresses. To accountfor it, a single new (1D) parameter E12 is introduced, which combines the geometrical aspect of grain boundary with its materialproperties and measures the average stiffness of grain boundary neighborhood along the grain boundary normal direction. It isdemonstrated that E12, in combination with Zener elastic anisotropy index A, is able to accurately predict normal stress fluctuationson any grain boundary type in a material with cubic lattice symmetry. It is argued that largest normal stresses most likely form ongrain boundaries whose normals are oriented along the stiffest direction in both adjacent grains (<111> for crystals with A > 1 or<001> for crystals with A < 1). Moreover, it is shown that classification of grain boundaries according to their propensity to exhibitlarge normal stresses can be trivially reduced to the (analytical) calculation of the corresponding effective stiffness parameter E12.A few practical implications are discussed relevant to intergranular stress-corrosion cracking of Coincidence Site Lattice grainboundaries. For example, it is highlighted that in face-centered cubic materials the coherent sigma3 twin grain boundaries, which areknown for their very high cracking resistance, nevertheless exhibit largest intergranular normal stresses, indicating that crackingresistance is associated with high grain boundary strength.
%G English
%2 https://cea.hal.science/cea-03748670/document
%2 https://cea.hal.science/cea-03748670/file/manu14.pdf
%L cea-03748670
%U https://cea.hal.science/cea-03748670
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%~ DEN
%~ CEA-UPSAY
%~ UNIV-PARIS-SACLAY
%~ DEN-SACLAY
%~ UNIVERSITE-PARIS-SACLAY
%~ GS-ENGINEERING
%~ MAP-CEA