Novel fabrication of more homogeneous water-soluble binder system feedstock by surface modification of oleic acid

Compared to conventional debinding process of wax-based binders used in ceramic injection molding, polyethylene glycol-based binders (water-soluble binders) with its high efficiency and environmental acceptability have appeared as a good alternative. However, water-soluble binder feedstock still presents some problems such as powder–binder separation or particle segregation which limits injected parts’ final properties. In the present work, we have successfully prepared the more homogeneous water-soluble feedstock with lower shear viscosity by a prior ball milling treatment to induce a small quantity of oleic acid to the surface of zirconia powders before the mixing process. Also, the surface modification mechanism of oleic acid to zirconia powders has been systematically discussed. With the modified powder, as-leached part with less agglomeration and phase separation has been fabricated, which suggests a novel modification method for fabricating injection molded ceramic parts by using water-soluble binders.