Influence of rice husk addition on the rheology and printability of alumina inks for direct ink writing

Pluronic F-127 based alumina-rice husk inks with different weight % of rice husk (1, 3, 5, 7.5, 10 wt.%) were prepared and rheological characteristic of the inks was studied. The concentration of rice husk in the solid content of the ink was 1.5%, 4.6%, 7.7%, 11.5%, and 15.4%. The gelation temperature was observed to decrease with an increase in rice husk wt.% from 23 °C to 7 °C. The XRD of the sintered sample showed the presence of quartz and nepheline derived from rice husk and alumina. The microstructure of sintered alumina showed that porosity increased with increasing rice husk content. The relative density of the samples sintered at 1350 °C and 1600 °C was observed to be between 80.6% and 62.5%, and between 83.8% and 76.3%. This study shows that the microstructure of 3D-printed parts can be tailored by adding rice husk to alumina-PF127 inks by direct ink writing.