Drying Behaviour of Gelcast Green Alumina Parts Utilizing PEG Solution

In this work, gelcast alumina green parts were dried by utilizing polyethylene glycol (PEG) solution as the liquid desiccant medium. The parts lost about 30-40 wt% of internal water in a reasonable period of time, i.e. 2-3 h and accomplished most of the shrinkage uniformly, then the part could continue drying in air at the room conditions. Finally, a defect-free porous part could be obtained after the process of the binder burnout at 900 degrees C. The results show that the green part loses more weight at a higher rate while drying in the PEG6000 solution than in the other PEG solutions with different PEG molecular weight. The solid loading of the alumina slurry and the concentration of PEG solution also affect the drying process significantly.