Page 114 - MSAM-4-2

Materials Science in Additive Manufacturing Impact of cell angle on AlSi10Mg structures

formation and dimple rupture before transitioning to rapid those with lower porosity exhibit more intense oscillations
brittle cleavage failure. This highlights the typical sequential than their higher porosity counterparts. This behavior can
nature of dynamic fracture processes, such as impact and be attributed to the rapid deformation of high porosity
fatigue deformation. Moreover, the loading distribution structures under impact loading, which enables a swift
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and stress concentration in porous structures vary transition to a dense state with minimal resistance.
according to the lattice structure design, leading to different Among the Dodeca structures in Figure 9A, variations
deformation modes, as reported in the literature. 2,4,60 These in oscillation intensity are observed, with Dodeca-A P80
results align with studies in the literature on LPBF-built showing the smoothest oscillations, followed by Dodeca-B
lattice structures and indicate that fracture characteristics P80, whereas Dodeca-C P80 displays the most intense
can be further optimized by adjusting strut thickness, unit oscillations. The intensity of these oscillations reflects
cell geometry, and porosity levels. 4,8,15 changes in the load-carrying capacity of the structures
upon impact and indicates the extent of damage sustained.
3.2.2. Influence of unit cell orientation under constant A significant reduction in load-carrying capacity may
impact energy (124 J) suggest the occurrence of large fractures within the porous
Impacting structures with different single-unit cell structures. The findings indicate that the geometry and
rotation angles at a constant energy level allows an orientation of the single-unit cells influence the oscillation
intuitive comparison of performance differences among patterns. In addition, as the porosity decreases slightly by
various designs. When subjected to an impact energy of 10% (from 90% to 80%) under the same impact energy, the
124 J, all structures experience oscillatory cycles during slope of the force-displacement curves increases, indicating
the deformation phase (Figure 9). Notably, the intensity a large enhancement in rigidity. There is also a notable
of these oscillations is more pronounced in the Dodeca variation in the peak force of oscillation among different
structure (Figure 9A and B) compared to the Octa porosities (Figure 9A-D), highlighting disparities in porous
structure (Figure 9C and D). Within each structure type, structural strength. The final displacements observed

A B

C D

Figure 9. Force-displacement curves under impact loading at an impact energy of 124 J for various porous structures. (A) Dodeca structures with 80%
porosity, (B) Dodeca structures with 90% porosity, (C) Octa structures with 80% porosity, and (D) Octa structures with 90% porosity
Abbreviations: Dodeca: Dodecahedral; Octa: Octahedral

Volume 4 Issue 2 (2025) 10 doi: 10.36922/MSAM025130019