Press-compaction-assisted binder jetting of textured ceramics

Abstract

In this work, textured ceramics were successfully obtained using press-compaction-assisted binder jetting for the first time. A mixture of alumina nanoplatelets and nanoparticles was used as the feedstock powder (the nanoplatelets served as templates for epitaxial grain growth during sintering while the nanoparticles were consumed by the grain growth). The nanoplatelet fraction in the mixture was varied from 0 wt% to 50 wt%. Green samples were prepared with a lab-designed press-compaction-assisted binder jetting machine. The green samples were then sintered in a furnace and their sintered densities were measured. A scanning electron microscope and X-ray diffractometer were used to investigate the degree of texture in the sintered samples. Finally, the biaxial flexural strength of the sintered samples was measured. As the nanoplatelet fraction increased, the sintered density decreased, but the degree of texture increased. Interestingly, the biaxial flexural strength of the sintered samples with 5 wt% or 10 wt% nanoplatelets was higher than those without nanoplatelets, suggesting the increased degree of texture has a stronger effect on the mechanical response than the reduced sintered density under these conditions.