Alumina Ceramic Gelcasting Forming Process, The Curing Stress Testing And Characterization

In this paper, used self-made cantilever sensor to study the inner stress during the transformation from suspension to the green bodies, the cracking of the green body arising from the stress and other properties were also investigated. The effects of slurry with different initial temperature, the addition of catalyst, the addition of initiator, monomer concentration, monomer and crosslinker ratio, the addition of moderator were studied, this parameters will act on the inner stress in the green body, lead to the phenomenon of different cracks in the green bodies after debinder, and effect green bodies'other properties.Increase the catalyst and initiator dosage and increasing initial temperature of the slurry can improve the gel casting of the curing rate and reduce stress from the slurry liquid to solid transition. The following conditions may reduce the curing stress and significantly improve the green body in the degree of cracking after row of plastic:①to maintain temperature and add the same amount of initiator, increased catalyst dosage from 50μl to 150μl;②to maintain the temperature and amount of catalyst is not Change, increased the addition of initiator from 100μl to 200μl;③to maintain the adding with same amount of catalyst and initiator, the slurry temperature increased from 25℃to 35℃.Regulating the liquid monomer content can improve or reduce the internal stress during the process of gel casting. Increased the monomer content from 10wt% to 25wt%, can reduce the gel point of time appeared, enhance the flexural strength of green bodies, improve the internal stress, increased degree of cracking after debinder time.Adjust the ratio of monomer and crosslinking agent can adjusted the stress slurry during the gel casting. When the ratio of monomer and crosslinking agent (mass ratio) increased from 70:1 to 10:1, increased degree of cracking after debinder time.With the increasing volume fraction of solid, the internal stress produced during slurry to green body reduces. When the solid volume fraction increased from 30vol% to 50vol%, the curing stress reduced, the degree of cracking after debinder time abated; With the increase of solid loading, drying is complete, solid volume fraction of 50vol% obtained linear shrinkage of the green body obtained green body was about 30vol% linear shrinkage of the half.With the added of HEA and PEG4000 as the representative stress of sustained release, 1 to 3% of the content, the green body can make the stress generated when the decrease in the curing. But the stress of sustained release dosage of more than 4%, will significantly affect the slurry rheology, the slurry viscosity, is not conducive to injection molding.