Abstract: Lattice structures are renowned for their high stiffness-to-weight ratios and remarkable energy adsorption capabilities. Although both the all-face-centered cubic with x-struts (AFCCX) structure and its original counterpart (AFCC) manifest satisfactory mechanical performance, the coupling influence of volume fraction and topology on their mechanical properties remains elusive. This work employed electron beam melting to fabricate Ti-6Al-4V AFCC and AFCCX structures with volume fractions of 10%, 20%, and 30% and systematically investigated their deformation behavior. Compared to the AFCC structures, the AFCCX structures demonstrate improved mechanical properties, with the elastic modulus increasing by 1.4%-10.3%, the compressive strength increasing by 8%-12%, and the energy absorption increasing by 8.0%-14.5% (25% strain). The x-struts effectively disperse the local strains in AFCCX and suppress the expansion of the cell during deformation. Therefore, more struts in the AFCCX structure are engaged in bearing the load, leading to an augmented structural efficiency. Notably, the x-struts cannot directly sustain the external loads. They do contribute to a modest enhancement in the stiffness and strength of the structures, thereby facilitating more effective engineering. This work offers valuable concepts for the straightforward design and optimization of lattice structures.

Key words: Lattice structure, Ti-6Al-4V, Electron beam melting, Volume fraction, Compressive behavior