Manufacturing of Porous Alumina Ceramic by Gel Casting

Various quantities of non-toxic monomer (2-hydroxyethyl methacrylate, HEMA) was added to form porous alumina ceramic by gel casting process. Pure water, monomer, cross-linker (N, N'-methylene-bis-acrylamide (MBAm)), and dispersant (ammonium salt of poly (methacrylic acid), PAS) were combined to form an aqueous solution, which added alumina powder and was milled to form alumina slurry with zirconia balls for 240 minutes. An initiator (ammonium persulfate, APS) was added to the alumina slurry with a vacuum mixing system and formed in an inverted metal mold. After heat treatment, curing, stripping and drying, the alumina green body was sintered at 1200, 1300, 1400, 1500 and 1600 ℃ for 1 h. The original alumina powder and sintered porous alumina ceramic materials were analyzed for particle size, viscosity, TGA/DTA, sintering density, porosity, SEM, XRD and bending strength. The results show that the porous alumina ceramic can be prepared with porosity of 12-48 wt% and bending strength of 17-153 MPa at various monomer content of 5-25 wt% and sintering temperatures of 1200-1500 ℃.