Compressive properties of electron beam melted lattice structures with density gradient

Abstract

Lattice structures are used in many applications such as lightweight design, energy absorbers and medical implants. Incorporating a density gradient in the design of lattice structures provides distinctive properties compared to designs with uniform density. In this study, density graded lattice structures of four different architectures were fabricated by electron beam melting technique with Ti-6Al-4V as building material. The samples were tested for compressive properties in comparison to their counterparts with uniform density. Under quasi-static uniaxial loading conditions, density graded samples exhibited more predictable deformation behavior and higher energy absorption than samples with uniform density. Observation with scanning electron microscopy showed that the fracture surfaces of the compressed density graded samples changed across the structure according to strut diameter. Finite element simulation was also conducted to compare the structural stiffness and to identify locations of highest stresses of the different lattice designs during deformation, and the results were compared with the deformation behavior observed from experiments. The distinctive properties of density graded lattice designs demonstrated in this study encourage further research to achieve advanced and tailored functionality.