Tailoring microstructures to improve thermomechanical behaviour of metallic alloys : Ti alloys for Aerospace applications

A more rational use of metallic materials for advanced applications (such as for example in aeronautics or fine mechanics) requires to generate the optimal microstructures through the control of the elaboration and fabrication processes. In this context, the description of the critical parameters of the microstructure of the metallic materials, which influence the mechanical properties, is necessary. This step requires the knowledge of the thermically and thermomecanically activated phenomenons (phase transformation, recrystallisation,...). The interpretation and the synthesis of these observations are integrated within physical models which provide the elements necessary to the development of the physical or mathematical macroscopic model. This paper will develop one example of the laboratory MMS researches (Special Metallic Materials) concerning the study of the physicochemical mechanisms controlling the microstructural genesis and the optimization of the mechanical properties. In the case of nanostructured alpha/beta titanium alloys, bonds between mechanical properties and active microstructural elements will be presented.