The thermal debinding of soluble binders in injection molded zirconia ceramic from room temperature to 250°C

In ceramic injection molding, the conventional solvent-debinding process encounters limitations such as solvent cost and environmental pollution. In this paper, a suitable thermal-debinding process from room temperature to 250 degrees C using carbon/alumina embedding powders with nano and submicron size was developed to remove the soluble binders replacing the conventional solvent debinding of injection molding ZrO2 ceramic. The effects of the embedding powders on microstructure and debinding ratio were studied in detail. The results showed that the main factor influencing debinding ratio was associated with the sufficient dispersing of mixed particles, which was characterized by the relative change ratio of tap volume. A debinding mechanism was proposed to explain the effects of carbon/alumina mixed powders on the debinding ratio and surface cracks. Based on the influencing mechanism, the debinded green part with the elimination of soluble binders and optimal surface was achieved using the mixed powders with C/A = 8/2 on the top and C/A = 4/6 on the bottom.