Hydrolysis assisted solidification (HAS) is a new method for net-shaping ceramic green parts from aqueous suspensions. The process exploits thermally activated and/or accelerated hydrolysis of aluminum nitride powder added to highly loaded ceramic suspensions. Several simultaneously occurring effects accompany the hydrolysis of AlN: an increase in the effective solids content of the suspension due to internal water consumption, a decreasing zeta potential due to ammonia formation, an increase in the surface area of the solid phase, etc. The overall result is a rapid increase of the suspension's viscosity and hence the setting of the low viscous suspension to form a rigid solid part. As a result, green parts can be prepared by slip-casting or injection molding within an impermeable mould. The present paper presents the basic principle of the hydrolysis-assisted solidification process and in addition, the preparation technique for forming alumina ceramic parts is described and the properties of the green and sintered products presented. The green parts of different size, formed by slip-casting or injection molding, show homogeneous microstructures and high green strength. The sintered alumina parts have high density, homogeneous microstructure and good mechanical properties.
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