Additive process effect on the characteristics of lattice structures made through EBM

Because of its unique geometry, lattice structures exhibit high strength, stiffness, and low weight with good mechanical efficiency. These structures are the best option for creating parts in the aviation and automotive industries because they allow for high levels of safety without significantly increasing weight, which affects fuel consumption and pollutant gas emissions. Many methods can be used to create these structures, but additive manufacturing is the most promising. The most commonly employed methods are selective laser melting (SLM) and electron beam melting (EBM). In the former, a laser beam melts the powder, whereas, in the latter, an electron beam performs this function. In previous work, a mismatch between theoretical and actual bending properties was found and partially attributed to geometrical unconformities; in fact, the produced specimens were lighter than expected, denoting a thinning of the trusses and skins due to the process. However, only a part of the deviation from the experimental results was compensated by reducing the diameter of the trusses and the thickness of the skins. Therefore, in this work, sandwich structures with lattice cores were produced through EBM process, and local mechanical characteristics were investigated to bridge the left gap. In particular, attention was paid to effective material properties, that, for thin trusses, differ from those of thicker elements.