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International Journal of Bioprinting Design of SLM-Ta artificial vertebral body

Figure 14. Deformation behavior and failure characteristics of the tantalum AVB-3 in the XOZ and YOZ observation planes at 0%, 5%, 10%, and 20%
strains. Abbreviation: AVB: Artificial vertebral body.

smooth overall in the plastic deformation stage without oscillations until the sample was densified, as exhibited in
stress oscillation, as shown in Figure 6C. Regions ① Figure 6C.
and ② in the stress–strain curve of AVB-2 correspond When the unit cells fill the limited space and form lattice
to the plastic deformation of the topologically thin wall. structures with varying sidewall curvatures, maintaining
The stress reduction in region ① was attributed to the the same porosity for LS-1, LS-2, and LS-3 requires
topological thin wall peeling off from the internal lattice sacrificing the integrity of some unit cells. Consequently,
structure. As the strain increased, the topologically thin these compromised unit cells cannot fully exhibit their
wall fractured at the location with the greatest degree of load-bearing capabilities. Reducing the sidewall curvatures
bending, causing a stress reduction in region ②. of the solid model results in an increase in the filling space,
thereby enhancing the number of unit cells within the
The topological thin-walled structure of AVB-3 lattice structure. The number of intact unit cells in LS-1, LS-
consisted of vertical struts, which were stretching- 2, and LS-3 was 117, 195, and 247, respectively. Therefore,
dominated. The lattice structure consisted of ISS unit as depicted in Figure 7, LS-3 exhibited the highest yield
cells, which were bending-dominated. Therefore, the strength and elastic modulus.
stress–strain curve of AVB-3 combines the characteristics
The sidewall struts of TTS-1 and TTS-2 were bending-
of stretching-dominated and bending-dominated porous dominant. As the sidewall curvature increased, the angle
structures. The buckling deformation of the topologically between the struts and the horizontal decreased, leading
thin wall, its separation from the lattice structure, and to a reduction in both strength and elastic modulus. When
subsequent fracture significantly reduced the stress the sidewall curvature was zero, the thin wall of TTS-3
during the plastic deformation phase (region ③). After consisted of vertical struts with stretching-dominated
the fracture of the topologically thin wall of AVB-3, the mechanical properties, which significantly enhanced the
bending-dominated lattice structures became the main load-bearing capacity of the AVB. However, the sidewall
load-bearing components. As a result, the subsequent curvature had a different effect on the forces between the
compression process yielded smooth curves without stress lattice and topological thin-walled structures.

Volume 11 Issue 4 (2025) 179 doi: 10.36922/IJB025150133