Abstract Scope |
Direct ink writing (DIW) of fine αalumina is limited by ink rheology, greenbody strength, and densification are impacted by the polymer binder. This study investigates the impact of various binders on printability, densification, and microstructural quality. Slurries containing aluminum oxide and one of three types of binders containing either polyvinyl alcohol (85–98 k Mw), polyvinylpyrrolidone (40 k Mw), or branched polyethyleneimine (25 k Mw), were extruded into five simple and five complex benchmark geometries. Dimensional accuracy was measured after drying and again after sintering to quantify shrinkage and imperfections, additionally, microstructure was analyzed by microscopy. Comparative assessment of rheology, green strength, and porosity revealed binder-dependent tradeoffs. This study compares three common binder variants and provides insight for tailoring binder systems to produce defect-free, high-performance alumina components by DIW. |