https://cea.hal.science/cea-03748670El Shawish, SamirSamirEl ShawishIJS - Jozef Stefan Institute [Ljubljana]Mede, TimonTimonMedeIJS - Jozef Stefan Institute [Ljubljana]Hure, JeremyJeremyHureLCMI - Laboratoire de Comportement Mécanique des Matériaux Irradiés - SEMI - Service d'Etudes des Matériaux Irradiés - DMN - Département des Matériaux pour le Nucléaire - CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) - CEA - Commissariat à l'énergie atomique et aux énergies alternatives - Université Paris-SaclayA single grain boundary parameter to characterize normal stress fluctuations in materials with elastic cubic grainsHAL CCSD2021IGSCCgrain boundary typecoincidence site latticeintergranular normal stress fluctuationsfinite element methodgrain boundary engineering[CHIM.MATE] Chemical Sciences/Material chemistryCEA, Contributeur MAP2022-08-09 19:31:242023-02-17 13:35:172022-08-12 17:18:34enJournal articleshttps://cea.hal.science/cea-03748670/document10.1016/j.euromechsol.2021.104293application/pdf1A 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.