Caractérisation et optimisation de structures treillis fabriquées par EBM

The recent development of Additive Manufacturing for the fabrication of metallic parts allows structures to be directly manufactured from 3D models. In particular, the "Electron Beam Melting" (EBM) technology is a suitable process which selectively melts a powder bed layer by layer. It can build very complex geometries but brings new limitations that have to be quantified.This work focuses on the structural and mechanical characterization of lattice structures produced by such technology. The structural characterization mainly rely on X-ray tomography whereas mechanical properties are assessed by uni-axial compression. The geometry and related properties of the fabricated structures are compared with the designed ones. For small strut size, the difference between the designed structure and the produced one is large enough to impact the desired mechanical properties. The concept of mechanical efficient volume is introduced. For the purpose of simulation, this concept is taken into account by replacing the struts by a cylinder with a textit{mechanical equivalent diameter}. After validation, it has been used into "realistic" simulation and optimization procedures, thus taking into account the process constraints.Post-treatments (Chemical Etching and Electro-Chemical Polishing) were applied on lattice structures to get rid of the inefficient matter by decreasing the surface roughness. The control of the size of the fabricated struts was improved by tuning the process strategies and parameters.