Slip Casting of a Si3N4-Based System

Silicon oxynitride ceramics were prepared by aqueous slip casting in plaster moulds. The colloidal behavior of slurries prepared with various dispersants was optimized through the electrokinetic sonic amplitude and rheological measurements. Samples with dimensions up to 5 x 10 x 2 cm were produced and the optimal processing and sintering conditions were determined. The flexural strength and dielectric constant of selected samples were similar to the values reported in literature for materials obtained with more expensive shaping techniques. The results showed that the preparation of large silicon oxynitride components by slip casting is feasible.