Etude ab-initio des propriétés structurales, électroniques et mécaniques des alliages d’aluminium utilisés en aéronautique.

Abstract

The intermetallic compounds, especially the transition metal aluminides TM-Al (Transition Metal Aluminides) have significant potential as high temperature materials. A number of their characteristics (microstructural stability, creep, hardness, ductility...) are directly related to their crystallographic structures and their electronic configurations and are therefore conditioned by the distribution properties of their atoms. However, their use is currently very limited because of their intrinsic ductilities virtually does not exist at room temperature. The main objective of this study is to improve the mechanical properties of these materials. For this, we have developed predictive models involving simple aluminum-based intermetallic compounds, layered structures of these materials and alloys of atom substitutions in intermetallic super-cells. As a result, we used ab initio simulations in the context of the Vanderbilt ultra-soft pseudo-potentials approximation using the VASP code