| Abstract Scope |
Laser powder bed fusion (LPBF) of aluminum alloys requires coordinated control of processing parameters to achieve high consolidation while retaining a useful post-yield mechanical response. In this study, a defect-sensitive process window was evaluated for an Al–Fe–Zr alloy using a balanced 80-condition matrix of laser power (275–375 W), scan speed (500–2000 mm s-1), and hatch spacing (0.06–0.12 mm), with layer thickness fixed at 0.06 mm. In addition to porosity and representative defect morphology, the post-yield response was quantified using the absolute stress reserve, Δσ=UTS-YS, and the normalized hardening capacity, H_c. H_cvaried from 0.32 to 28.99 %, demonstrating strong sensitivity to processing condition. Factorial decomposition showed that scan speed accounted for 62.91 % of the observed H_cvariation and the power–speed interaction for a further 26.74 %. The most favourable hardening response occurred at intermediate scan speeds, with the optimum power shifting from lower values at 1000 mm s-1 to higher values at 1500 mm s-1. Porosity was negatively associated with H_c(ρ=-0.658), but the combined process–porosity model provided the strongest cross-validated prediction (Q^2=0.737), showing that defect content constrains, but does not uniquely determine, the post-yield response. These results establish an interaction-sensitive process window in which both defect state and processing history must be considered when optimizing LPBF Al–Fe–Zr alloys. |