Study On Preparation For Alumina Ceramic By Novel Colloidal Forming

The green bodies of alumina were fabricated by gel-casting and boehmite as a binder in this paper. Characteristic, technological conditions and influencing factors of the two processes had been discussed separately. By means of FESEM and DTA-TG, the link between green body's microstructure and its properties were studied in this paper.In the process of gel-casting, how to prepare high solid content slurry with low viscosity was studied, the effects of dispersant selecting, content, pH, the ball milling time and solid content to the fluidity were discussed. The rich suspending liquid was obtained using PMAA-NH4 as a dispersant with solid content 55%, pH 10, viscosity 985mPa.s. Low poisonous organic monomers of N-Methyloacylamide and 2-Hydroxy-ethylester methacrylic acid were chosen, the influences of proportion and content of the organic monomer and the crosslinker on green body's bending strength, initiator and catalyst addition on solidify velocity had been studied. The better organic monomer was N-Methyloacylamide. The study also included the processes of drying and degreasing sintering; The surface-exfoliation phenomenon of green body was eliminated by adding polyethylene glycol.Alumina ceramic was formed after gelling and solidify using boehmite as a binder. The pasty stock was obtained using TAC as a dispersant with solid content 50%, boehmite 9wt%, viscosity 960mPa.s. The green body's bending strength was 3.916MPa after jelling and drying under special temperature and time using nitric acid as a curing agent. The influences of boehmite on slurry viscosity, bending strength and sintered body density were also studied.