Deformation and energy absorption studies on additive manufactured Ti–6Al–4V alloy with gradient lattice structures

Lattice structure has received extensive attention because of its high strength-to-weight ratio. In this study, a series of novel gradient lattice structures (GLS) were designed and manufactured by selective laser melting (SLM). Based on the uniform lattice structure (ULS), the angle between the rods in the middle layer is changed to 60°, 90° and 120°, respectively. The mechanical properties and deformation behaviors were analyzed by quasi-static compression tests and finite element analysis. The compressive strength of the GLS with variable strut angle was significantly improved compared with that of the ULS. Compared with the ULS 60° sample, the compressive strength of the GLS 60° sample increased by 114 MPa while reducing the weight by 31.4 %. The GLS 90° and GLS 120° samples have stronger energy absorption capacity than the corresponding ULS samples. The gradient of the strut angle did not change the failure mechanism of shear failure under quasi-static loading conditions. However, due to the difference in the stiffness of the middle layer, the deformation degree of the three GLS samples during compression is different. This study provides valuable guidance for the research and development of lattice structures of high-performance Ti–6Al–4V alloys. Methodology of present study.