Drying-induced forming of alumina ceramics using high solid-loaded slurries with addition of glycerol

摘要

A new drying-induced forming (DIP) of ceramics has been developed using high solid-loaded alumina slurries with addition of glycerol, in which the slurry was simply dried in an open mold at the ambient condition. The drying-induced forming approach is facilitated by the high stability of concentrated slurries during drying where glycerol was added to maximize the critical solid loading and play simultaneously as a drying control agent. The drying and rheological behaviors of slurries were examined with respect to the glycerol addition. A slurry of 60 vol percent solid loading with 20 wt percent glycerol addition was chosen for the drying induced forming test. The green samples exhibited no bending or cracks, and a small degree of shrinkage anisotropy during sintering. The sintered samples showed a high relative density of 99.2 percent and an average strength of 420 MPa. We demonstrate here a possibility of producing near-net-shaped and bulk ceramic components in a simple scheme by using the drying-induced approach.