Issue 62

F. Cantaboni et alii, Frattura ed Integrità Strutturale, 62 (2022) 490-504; DOI: 10.3221/IGF-ESIS.62.33

The energy absorption data are reported in Fig. 6. After the heat treatment, it growths for all the samples independently from the cell morphology. This means that that the samples are able to reach higher deformation and therefore to absorb more energy when stressed. This behavior is consistent with the decrease in hardness recorded after heat treatment and appears interesting for applications in the biomedical fields, such as for surgical implants and tools [2,50].

Figure 6: Energy absorption values of the samples.

The reported mechanical performance is in accordance with the literature [18,32,49,51-53]. In particular, the results obtained were compared with the literature to identify the main differences between the radially graded porous structure and uniformly distributed ones. The mechanical properties such as ultimate strength, yield stress, hardness, and energy absorption presented similar values for each configuration of the cell [1], [32], [37,53–55]. Instead, the radial arrangements give the lattices a stiffness homogenization along the planes perpendicular to the symmetry axis, contrary to the non-radially graded lattices, which are characterized by anisotropic stiffness [56,57].

Figure 7: Main failure modes after compression test on AB sample: a) FCC90, b) DM90, c) DG90, d) FCC0, e) DM0 and f) DG0. Failure modes and Fracture analysis The compression tests were ended after the first major structural collapse, usually signified by the fracture of the specimen into multiple pieces. Otherwise, they were terminated when the sample reached the strain of 50%-60%. Some examples of specimen failure, representative of the analysed AB samples, are reported in Figure 7.

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