Mechanical properties and energy absorption capability of functionally graded F2BCC lattice fabricated by SLM

Metallic lattice structures with complex internal design can be fabricated using selective laser melting (SLM) additive manufacturing technology. These lattice structures are finding many applications such as in personal protective equipment and packaging due to their distinctive properties, combining the lightweight and high strength. In this study, experimental compression tests and finite element analysis (FEA) were conducted to investigate and compare the mechanical properties and energy absorption capability of functionally graded and uniform F2BCC lattice structures made of Al-12Si aluminium alloy and manufactured by SLM process. The solid struts diameters and surface morphology were examined using scanning electron microscope. The functionally graded lattice structures were found to exhibit distinct deformation behaviour as compared to the uniform lattice structure. Results of finite element analysis were found to be in qualitative agreement with the experimental data and with the predictions of the analytical models for graded lattice structure. The total cumulative energy absorption per unit volume was higher in functionally graded lattice than in uniform lattice. Finally, mechanical characteristics and coefficients of three Gibson and Ashby analytical equations were also determined, which could be used to estimate the mechanical properties of other SLM fabricated functionally graded lattice structures.