Résumé. 2014 Le bicristal de silicium contenant le joint de flexion 03A3=9 (122) [011] est utilisé comme matériau modèle pour étudier, à l'aide de la microscopie électronique à haute résolution, les méca-nismes de déformation à l'échelle atomique. Les (122) [011] is used as a model in order to study the very early stages of the mechanisms occurring at atomic scale close to the GB. The high resolution electron microscopy observations showed that most dislocations induced by the deformation integrated the GB by glide and climb. The evolution of the structure of the original GB has been studied for different strains and at different temperatures. The accumulation of the DSC dislocations into the GB leads to a variation in the misorientation angle between the two grains. In compression it increases, whereas it decreases in tension. Consequently, various E GBs have been detected. The key points are that, firstly, the structural evolution of the GB can be described with a limited number of structural units and secondly, depending on the deformation temperature, one 03A3 GB can exhibit two different structures.