Fabrication of α-sialon sheets by tape castingand pressureless sintering

Sheets of α-sialon were prepared by tape casting and pressureless sintering. Suspensions consisting of precursor α-sialon powders, dispersant, binder, plasticizer, and 60 MEK/40E as solvent were optimized for tape casting by rheological measurements. Crack-free green tapes with good flexibility and high strength were obtained from suspensions with suitable rheological properties (moderate viscosity, shear-thinning behavior, and negligible thixotropy). The obtained green tapes showed great homogeneity by means of scanning electron microscope observation and pore-size distribution, leading to homogeneous α-sialon sheets after pressureless sintering at 1750 °C for 2 h. The results showed that it was possible to fabricate homogeneous α-sialon sheets with smooth surfaces through tape casting and pressureless sintering.