Ceramic suspensions tape casting

Tape casting is used to produce a green body which consists of a thin layer of a dried ceramic suspension. These green layers can be cut into a near-net shape and sintered to give a useful ceramic object. In addition, these thin ceramic layers can be layered to produce a multilayer structure like that of the multilayer capacitor shown in Figure... 

A related technique used to produce very thin, virtually continuous tapes (0.1 mm) of ceramic materials is tape casting. This involves the preparation of a colloidal suspension which is transported on a carrier... 

Moist granular ceramics produced by using the common forming methods, such as tape casting and extrusion, should be dried before the binder burnout and sintering. Drying is also a key step in solid firee-form fabrication techniques that involve layer-by-layer deposition of colloidal suspensions. 

Rheological methods are widely used to determine the properties of concentrated ceramic suspensions. Rheology can be used as an analysis method, e.g. when determining the optimal amount of dispersant from measurements of viscosity versus the amount of dispersant added. In addition, rheological measurements are often used for quality control in order to minimize the batch-to-batch variation before a ceramic suspension is processed further, e.g. spray dried or tape cast. The rheological behaviour can also be used as a direct process parameter, which should be appropriately adjusted to obtain the optimal green-body properties after forming. 

Casting in ceramics is different from solid casting in metals. Flere, a suspension or a slurry of ceramic powder is prepared and poured into a mold. This mold absorbs the liquid and leaves the solid with its internal shape imparted to it. The same method is used in powder metallurgy to produce porous parts. The slurry can also be used to produce tapes, where the method is called tape casting. 

Y. Zhang, C. Qin, and J. Binner. (2006). Processing multi-channel alumina membranes by tape casting latex-based suspensions, Ceram. Int. 32 811-818. 

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