Abstract : Several proceedings have been applied to improve metals and metallic alloys mechanical properties: change of composition, microstructure, and texture changes following various thermo-mechanical treatments. One new hope, based on the different behaviors of grain boundaries under mechanical solicitation, is emerging. The researches in this field are still in their infancy, but the present paper attempts to demonstrate that macroscopic behavior changes are likely to occur due to the modification of the grain boundary distribution in a polycrystal. This requires first to investigate the answer of individual grain boundaries to strains coming mainly from their interactions with the lattice dislocations.