Influence of the Slip Composition on the Properties of Tape-cast Li_(1.075)Nb_(0.625)Ti_(0.45)O_3 Aqueous Slurry

The aqueous tape casting process is systematically developed and investigated for the tape casting of Li1.075Nb0.625Ti0.45O3 microwave ceramic. The well-dispersed aqueous Li1.075Nb0.625Ti0.45O3 slurries are prepared,which with water-soluble PVA as binder,ethylene alcohol as plasticizer,and ammonium salt of polycarboxylate as dispersant. The influence of the slip composition on the dispersion and the rheological behavior of the suspension are stu-died. Effect of dispersant amount on the viscosity of the ceramic slurry is investigated. The amount of the dispersant required to achieve a minimum of viscosity is equal to 0.2wt%. It is revealed that the flow properties are remarkably influenced by the concentration of PVA and ethylene alcohol. The rheological test indicates that the ceramic slurry exhibits a typical shear-thinning behavior and scarcely no time dependent behavior. In addition,SEM micrographs show that the microstructure of the green ceramic sheets is homogeneous.