Metal-based additive manufacturing (MBAM) has enabled rapid prototyping and one-off production, but the cost of equipment has limited widespread adoption. Recent developments in hybrid filaments and processes have created more accessible methods for MBAM, leveraging common fused filament fabrication (FFF) printers and Ultrafuse 316L metal filament. This technique has shown promise but suffered from large pore formations along parallel print paths. To reduce the formation of process-dependent pores, a design of experiments (DOE) was conducted to investigate the effects of varying extrusion parameters such as layer height, line width, and extrusion multiplier for tensile samples produced on a Creality Ender 3 V2 and MakerBot Method X. Characterization techniques included tensile testing, microhardness, density measurements, and optical microscopy; findings were compared to samples produced via laser-powder bed fusion (L-PBF) and from 316L plate. The Method X produced components with approximately 1% porosity and the Ender 4% porosity. Mechanical properties for both FFF printers were comparable to previous research, with an increase in tensile strength for the Method X. Despite the increased porosity in the Ender samples, only a 7% reduction in strength from the average yield in Method X samples (153.6 MPa) was observed. It was found that a combination of increased layer height and extrusion rate led to improved mechanical properties in parts printed on the Ender, while the default Makerbot settings resulted in the best overall performance for Ultrafuse 316L samples.

Wire-arc directed energy deposition (arc-DED) of maraging 250 (M250) steel is of growing interest for aerospace, tooling, and defense applications, yet systematic process characterization data remain limited. This study presents a mixed quantitative–qualitative factorial comparison of three Fronius synergic transfer modes, GMAW-CMT-Mix, GMAW-CMT-Universal, and GMAW-Pulsed-Arc, for single-bead M250 deposition across wire feed speeds of 4.45 to 8.26 m/min and travel speeds of 0.3 to 1.5 m/min. Bead geometry and process behavior are characterized using non-contact optical profilometry and destructive methods (i.e., metallographic sectioning, optical microscopy, and Vickers microhardness). The material feed rate ratio, R_wt, is introduced as a unifying process descriptor; heat input and cross-sectional area scale linearly with R_wt, while travel speed primarily governs bead height and wire feed speed primarily governs bead width. At the highest travel speed tested, GMAW-CMT-Mix and GMAW-Pulsed-Arc exhibit bead humping, rendering those conditions unsuitable, while GMAW-CMT-Universal maintains stable deposition with consistent dilution and the lowest heat input at equivalent R_wt. GMAW-CMT-Mix yielded the highest dilution and hardness. Linear regression of process responses against R_wt gives $R^2$ exceeding 0.83 for both height and width across all modes. These results establish a characterization baseline supporting future multi-layer studies.