Development of water soluble binder systems for low pressure injection molding of alumina

Low pressure injection molding of alumina powder using a water-soluble binder system has been carried out successfully. The water-soluble based binder system consisted of Poly (2-ethyl-2-oxaline), low density polyethylene and stearic acid. The critical powder loading of the binder-powder mixture was determined based on torque rheometry experiments. The theological properties of the powder-binder mixture were investigated systematically. The binder system used provides satisfactory mixture stability, excellent mouldability and reasonably fast water leaching and thermal debinding rates. The water-soluble constituent, poly (2-ethyl-2-oxaline), was removed by leaching in convecting water at 60degreesC within 6 hour. The remaining binder constituents were thermally removed during heating to 450degreesC. Sintering of the parts was conducted at 1550degreesC for an hour in air.