Abstract：The direct foaming method combined with gelcasting was employed to prepare mullite ceramic foam. Triacetin, polyimide and hydroxypropyl cellulose were creatively proposed as gelling agent for gelcasting process, respectively. The influence of gelling agent on rheological properties and the correlation rule with the curing time were studied. The results show that different kinds of gelling agent have different influence on rheological properties. It is considered that the rheological properties have significant influence on the curing time. Ameliorating the thixotropy, improving the rate of viscosity growth, and enlarging the linear viscoelastic domain of foam slurry are conducive to shorten the curing time of foam slurry. Among these three gelling agents, the triacetin obtains the optimal effects, the initial curing time and curing time of foam slurry is both shortest.
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