Gelcasting of Alumina with Low-toxicity HEMA System

The industrialization of gelcasting technique based on the acrylamide system has been prevented to some extent because acrylamide is a neurotoxin monomer. In this paper another gelcasting based on the polymerization of low-toxicity 2-hydroxyethyl methacrylate (HEMA) was successfully developed. The rheological properties of alumina suspensions with two dispersants, JN281 and tri-ammonium citrite (TAC), in the new system were compared. The results show that JN281 is more effective for the new system than the frequently used TAC. High solids loading ceramic suspension with low viscosity can be prepared by addition of JN281. The green bodies made through the new system have smooth surface with a dried green strength of 18MPa. The SEM photos also indicate that the green bodies have a homogeneous microscopic structure. Dense complex-shape ceramic parts were successfully produced through the new gelcasting system.