Laser Powder Bed Fusion Additive Manufacturing of Fe3Al-1.5Ta Iron Aluminide with Strengthening Laves Phase

Advanced aluminides strengthened with incoherent Laves phase precipitates are promising lightweight and creep-resistant alternatives for high-alloy steels superalloys high-temperature critical components up to 750 °C service temperature. A significant issue manufacturing these conventional casting is the strong coarsening tendency of at elevated temperatures, leading a strength reduction. In this context, short lifetime melt pool in additive its fast solidification cooling rates promise consolidate homogeneously distributed fine particles without coarsening. The main scientific objective work exploit unique characteristics laser powder bed fusion (L-PBF) (AM) process print dense crack-free bulk Fe3Al-1.5Ta samples containing uniformly (Fe, Al)2Ta precipitates. Fe-25Al-2Ta (at.%) alloy was selected since creep resistance 650 surpasses one P92 martensitic–ferritic steel (one most alloys developed steam turbine applications). Fundamentals on process–microstructure relationships governing L-PBF-fabricated builds provided by detailed microstructural characterization using X-ray diffractometer (XRD) ultra-high-resolution scanning electron microscopy (SEM) equipped energy-dispersive spectroscopy (EDX) high-resolution backscatter diffraction (EBSD) detectors. Orientation imaging (OIM) grain reference orientation deviation (GROD) maps were applied measure texture visualize substructures within grains. mechanism voids formation, morphology, volume fraction as function input energy density identified. melting dynamics led microstructures large columnar grains, porosity, periodic cracks during printing process. Processing building temperatures below brittle-to-ductile transition temperature, BDTT (750 °C), often caused severe macrocracking delamination. Crack-free densities higher than 99%, some approaching 99.5%, fabricated from pre-alloyed gas-atomized powders combination high power (250–300 W), slow-to-medium speed (500–1000 mm/s), 800 build plate preheating 67° rotation strategy. morphology pores indicated relatively sharp spherical geometry speeds 1000 mm/s crack-like values. ultra-fast L-PBF suppressed D03 Fe3Al-ordering. characterized B2 FeAl-type order clusters dispersed disordered A2 ?-(Fe, Al) matrix. Additionally, (C14–P63/mmc) predominantly formed matrix boundaries frequently quantitative EDX analysis gave 77.6–77.9 at.% Fe, 21.4–21.7 Al, 0.6–0.8 Ta, while composition 66.3–67.8 8.7–9.8 22.4–24.9 indicating that considerably enriched Ta respect coarse, grains which grow epitaxially substrate, several m width, extended across layers along direction. exhibited microtexture close <0 0 1> showed hardness value comparable as-cast spark plasma-sintered counterparts. negligible variation height observed. Within framework study, we demonstrated porosity cracking issues could be resolved mainly controlling parameters platform above BDTT. Nevertheless, modifications and/or post-manufacturing processing required microstructure refinement.