Tape casting of non-aqueous silicon nitride slips

Tape casting is a powerful method for the manufacturing of flat, large area ceramic components. Silicon nitride is a reference material for high tempe rature structural applications. Between them, thick film/coating technologi es and ceramic-ceramic joining are receiving an increased attention. In thi s work, the rheological behavior on non-aqueous silicon nitride slips for t ape casting was investigated considering different solvent and binding syst ems.. by controlling the total binder and plasticizer content and the binde r to plasticizer ratio. A phosphate ester was used as dispersant. The chara cteristics of the green tapes obtained in different conditions were studied in terms of density, thickness and microstructure and related with the rhe ological properties of the slips. Once the slip properties were adjusted, m anufacturing parameters, such as the casting speed and the gap between the blades and the carrier substrate, were also analyzed in order to improve th e green tape properties and the process reliability. In order to obtain sin terable compacts, Al2O3 and Y2O3 were used as sintering aids. The effect of the sintering aids in both the rheological behavior and the green characte ristics was also studied. (C) 2000 Elsevier Science Ltd. All rights reserve d.