PSI - Issue 83

Ahmad Issmail et al. / Procedia Structural Integrity 83 (2026) 229–238

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Fig. 5: Fracture surfaces (a1-d1), crack initiation defects (a2-d2), and crack propagation stages (e-f) observed with SEM of the investigated specimens tested at a nominal stress level of 150MPa 4. Conclusions This study adopted microstructural homogenizing T6 heat treatment to investigate the roughness-dominated surface monotonic and fatigue response of PBF-LB AlSi10Mg. Standard specimens with different build orientations demonstrated identical stress-strain behavior before fracture, yielding the same tensile strength while exhibiting differences in elongation at break depending on the degree of irregularity of the surface texture. Fatigue performance trends were overall consistent with the surface roughness profiles, with specimens with higher surface roughness yielding shorter fatigue lives. As such, miniature specimens exhibited improved fatigue performance and lower scatter compared to standard specimens. In contrast, m|H exhibited comparable fatigue behavior to m|45° despite its significantly higher surface roughness measurements, likely owing to blunter surface roughness valleys combined with the benign nature of the support remnants and unfused powder particles that contributed to its high registered values of R a , R z , and R v .