Study on gelation process of gelcasting for superfine zirconia using DMAA gel system

The effects of vacuum degassing time, initiator, monomer, crosslinker/monomer, gelation temperature and solid content on gelation process of low-toxicity DMAA monomer as well as the properties of green bodies were studied. Complex shape green bodies with smooth surface, without cracking and exfoliation were successfully prepared. When the amount of monomer is 15%, the crosslinker/monomer is 1:50, the addition of initiator is 1% and the temperature is 60°C, the green bodies prepared by 52vol% slurry show a bending strength close to 30 MPa, which can be directly machined. Mercury porosimetry and SEM indicate that the green bodies have homogeneous microstructure, without aggregation and particle-clusters. In addition, ideal pore structure with low porosity(26%), small pore size(the most concentrative pore diameter is 36 nm), narrow and unimodal pore size distribution of green bodies are observed.