This work examines how feedstock composition and process settings influence the performance of Al-6061 parts made through material extrusion (MEX). A feedstock with 57 vol% (78 wt%) solids loading was selected based on torque rheometry, showing stable flow and shear-thinning behavior with a measured viscosity of 710.9 ± 3.2 Pa·s. Filaments produced from this material had a consistent diameter of 1.74 ± 0.0064 mm and were used to print specimens at extrusion multipliers of 0.9, 0.95, and 1.0. Debinding and sintering procedures, guided by thermal analysis, resulted in a peak density over 97% of the theoretical value. Among the conditions tested, the 0.95 extrusion multiplier produced the most favorable mechanical properties, with an ultimate tensile strength of 153.5 ± 3 MPa, a yield strength of 68.2 ± 11.7 MPa, and elongation reaching 28 ± 3%, which aligns with values reported for annealed Al-6061. Fractographic analysis showed a ductile fracture mode, confirming good interlayer adhesion and consistent sintering. These results show that MEX is a reliable method for fabricating Al-6061 parts with complex geometries and stable mechanical performance.

Polymer‐coated ceramic powders (PCCPs) prepared via a thermally induced phase separation (TIPS) process have emerged as a promising alternative for enhancing the processability and mechanical properties of highly filled ceramic polymer compounds. This study investigates the performance of PCCP, specifically alumina particles coated with polybutylene terephthalate (PBT), compared to conventional admix compounds prepared through melt‐mixing. The research explores the viscosity, flowability, packing efficiency, and thermal stability of PCCP at 50 and 60 vol.% solids loadings. The results indicate that PCCP exhibits significantly lower viscosity across all shear rates, with a 54.1% reduction at 1000 s ^‒1 compared to admixes at 50% loading, which can help to improve mold filling behavior and reduce processing defects. Additionally, PCCPs demonstrate enhanced powder flowability, as evidenced by a lower Hausner ratio (1.15 for 50% PCCP vs. 1.56 for alumina particles) and high pycnometer density (2.81 g/cm ³ ), suggesting good packing efficiency. At 60% loading, all compounds exhibited significantly increased viscosity, indicating the challenges associated with high solids loading, while PCCP maintained improved rheological performance under these conditions. The findings highlight PCCPs as a better alternative to conventional, ad‐mixed ceramic‒polymer compounds, offering enhanced flow characteristics at industrially relevant shear rates, better packing, and improved thermal behavior, making it a viable option for high‐performance ceramic injection molding applications.