Effect of cell geometry on the compressive behaviour of β-titanium alloy lattices under various strain rates

In this study, a β-type Ti–3Al–6Fe–6V–2Zr (wt.%, hereafter referred to as Ti3662) alloy lattices with cubic (CUB), rhombic dodecahedron (RHO) and topology-optimised (TOP) unit cells were fabricated using the laser powder bed fusion (LPBF) technique. Compression tests were conducted at various strain rates, and the results were compared with those of Ti–6Al–4V lattices. The findings show that both compressive strength and energy absorption efficiency increase with increasing strain rate, although to different extents depending on the lattice geometry. The bending-dominated TOP lattice exhibits the highest strain-rate sensitivity (SRS) because of enhanced structural rotational inertia and a more uniform stress distribution within the struts. In contrast, the buckling-dominated CUB lattice shows the lowest SRS and which is primarily governed by the intrinsic properties of the parent materials. Compared with Ti–6Al–4V lattice, Ti3662 lattices demonstrate higher SRS owing to their higher activation energy of dislocation slip mechanisms under various deformation rates.