Development of a tape casting process for making thin layers of Si3N4 and Si3N4 + TiN

A process for the tape casting of silicon nitride ceramics has been developed and is described in detail. A solvent (ethanol) based recipe was developed using polyvinyl butyral and polyethylene glycol as the binder and plasticizer, respectively. The effect, of milling times, dispersant, solvent, plasticizer and binder contents were all investigated as well as that of the binder to plasticizer ratio. In addition the beneficial effect of multi-stage milling of the slip was evaluated. The removal of the ceramic tape from the carrier film is described. In addition the recipe and process used for producing silicon nitride tape was successfully adapted for the production of two different silicon nitride + titanium nitride composite based tapes. From the tapes produced it was possible to hot press dense multi-layer laminate structures with the thinnest layers being 45 μm thick.