Abstract: In order to get enough operating time in gelcasting processing, we hope ceramic slurry delay solidification. Idle time commonly is postponed by decreasing slurry temperature and the
amount of initiator and catalyst. In this paper, other ways were studied. The heat evolution of the slurry was measured to characterize the
polymerization process. Results show that increasing ionic strength can delay polymerization reaction. Idle time is shortened when pH of slurry
decreased but mounted up rapidly when pH of slurry is under 1.7. Various inhibitors have different inhibit effect on polymerization under different
temperatures. Composite inhibitor of phenothiazine and catechol can delay solidification of ceramic slurry effectively under 20～60℃.

Key words: gelcasting, idle time, ionic strength, inhibitor