The biggest challenge of architectured materials was the processing route. With the recent development of additive manufacturing, it is now much easier to produce sophisticated geometries. SIMaP is now equipped with two EBM machines.
Illustration of the concept of mechanical efficiency. In red is highlighted the mechanical equivalent cylinder, i.e. a perfect cylinder having a stiffness equal to the as-built structure.
Lattice structures were produced by EBM and characterized structurally as well as mechanically. X-ray tomography was extensively used in order to characterize lattice structures in 3D. The discrepancies between the ideal properties (those of the CAD file) and the effective properties of the produced structure were investigated based on the concept of mechanical efficiency. This concept allows to discriminate the material that transmit loads with the one which doesn't.
Effect of chemical etching on a single vertical strut as a function of the etching time.
Significant surface defects can be observed on as-built structures and are not considered as mechanically efficient. The effect of chemical etching on the surface defects was investigated. The chemical etching clearly improves the mechanical efficiency of the lattice structures. This is further illustrated in the above figure that shows the evolution of the strut morphology as a function of etching time. The surface profile after a 30 min etching time appears much smoother than the as-built profile.
Rédigé par Christophe Martin
mise à jour le 15 mars 2018