Fig. 1. Optical micrographs depicting the melt-pool morphologies of (a) as-fabricated Al-2.5 wt% Fe alloy sample and (b) sample exposed to 300 °C for 1000 h.

Fig. 2. EBSD orientation maps coupled with grain boundaries showing the α-Al (fcc) matrix of (a) as-fabricated Al-2.5 wt% Fe alloy sample and samples exposed to 300 °C for (b) 100 h and (c) 1000 h. The colors represent orientations along the Z direction (building direction) in terms of the orientation color code, and the fine lines and bold lines in the maps correspond to misorientations (θ) of 1 < θ < 15° and θ > 15°, respectively.

Fig. 3. (a) Fraction of HABs, (b) average orientation angle, and (c) mean spacing of HABs for the α-Al matrix of the as-fabricated sample upon exposure to 300 °C for different periods.

Fig. 4. XRD spectra of as-fabricated sample and samples exposed to 300 °C for different periods.

Fig. 5. SEM micrographs depicting the representative microstructure of (a) as-fabricated sample and samples exposed to 300 °C for (b) 10 h, (c) 100 h, and (d) 1000 h.

Fig. 6. TEM images showing the Al-Fe phases distributed inside the melt pool of (a) as-fabricated sample and samples exposed to 300 °C for (b) 10 h, (c) 100 h, and (d) 1000 h.

Fig. 7. (a) TEM bright-field images showing the Al-Fe phases distributed inside the melt pool and (b) electron diffraction patterns captured in the enclosed area of the experimental Al-2.5 wt% Fe alloy sample exposed to 300 °C for 1000 h.

Fig. 8. HAADF-STEM images and the corresponding EDS elemental mappings of Al-Fe phase particles dispersed in the α-Al matrix of the experimental samples exposed to 300 °C for (a) 10 h and (b) 1000 h.

Fig. 9. Mean particle size of the Al-Fe phases distributed inside the melt pool of the experimental samples exposed to 300 °C for different periods.

Fig. 10. Variation in (a) Vickers hardness and (b) thermal conductivities of the experimental Al-2.5 wt% Fe alloy samples.

Fig. 11. Nominal strain-stress curves of the experimental specimens subjected to tensile deformation at ambient temperature along (a) the Z direction and (b) the X/Y direction.

Fig. 12. Fracture surface morphologies of (a, b) as-fabricated specimen and the specimens exposed at 300 °C for (c, d) 100 h and (e, f) 1000 h, which were subjected to tensile deformation along (a, c, e) the Z direction and (b, d, f) the X/Y direction.

Fig. 13. (a) SEM micrographs depicting the distribution of coarsened Al-Fe phases in the α-Al matrix of the experimental Al-2.5 wt% Fe alloy sample exposed to 300 °C for 1000 h, (b) magnified view of the region enclosed by white dashed lines in (a), (c) corresponding orientation color map of the region shown in (b), and (d) the pinning effect of the nanosized Al13Fe4 phase on grain boundaries.

Fig. 14. Variation of (a) Fe concentration in the matrix and (b) lattice parameter of Al of experimental Al-2.5 wt% Fe alloy samples after thermal exposure at 300 °C for different periods.

Fig. 15. Variation of the lattice parameter as a function of Fe concentration in the present study compared with previously reported data for Al-Fe binary alloys.