A Study on Compression Behavior and Fracture Morphology in Dumbbell-Shaped Ti6Al4V Lattice Structures Fabricated through Additive Manufacturing

In this study, Ti6Al4V alloy was investigated for its potential applications in aerospace and biomedical fields, owing to its exceptional strength-to-weight ratio and lightweight properties. The compression behavior and deformation characteristics of a novel lattice structure inspired by a dumbbell design were investigated under controlled conditions. The analysis revealed a layer-by-layer collapse of the lattice structures, with stiffness maintained across all layers. Finite element analysis (FEA) was performed using Abaqus to simulate the deformation behavior, and the results were compared with experimental data. The surface quality of the 3D-printed lattices was assessed using scanning electron microscopy (SEM), through which detailed information on surface defects and chemical composition was obtained. The crystallographic texture and grain orientation of the material were characterized using electron backscatter diffraction (EBSD), while phase identification was carried out by using X-ray diffraction (XRD). Additionally, the dimensional accuracy and presence of internal pores in the fabricated lattice structures were evaluated through micro-CT analysis. The comparative analysis of the three designs, incorporating both FEA simulations and experimental data, provided comprehensive insights in to their deformation mechanisms, stress distribution, and overall structural integrity under compressive loading. The compression experiment shows that, the deformations occur by the localized buckling which occurs cross sections of the struts, resulting in 45° breaks observed in all struts of each row during failure. After the collapse of each row, the stress–strain curve shows a temporary dip before increasing again as the load redistributes to the remaining intact rows. This behavior illustrates how the structure can continue to support additional load until ultimate failure occurs after all rows have succumbed to localized buckling.