A Physical Model for Drying of Gelcast Ceramics

Gelcasting is a promising new technology for manufacturing advanced structural ceramic components. The process involves drying of the ‘green’ gelcast part before densiï¬cation. The physical mechanisms controlling this relatively long drying process are not well understood. In this study, several controlled experiments were performed to elucidate the key mechanisms. A one-dimensional drying model was formulated based on evaporation and gaseous diffusion through the part. Experimental data were used to obtain correlations for model parameters. This model predicts the instantaneous moisture content of a gelcast sample with an accuracy of better than 10% when dryer humidity and temperature, and sample thickness are speciï¬ed.