Study on rheological behavior of slurry for aluminum nitride ceramics

Effects on the rheological behavior of slurry for tape-casting aluminum nitride substrate were studied systematically. The effects of milling time, solvent, dispersant, binder and plasticizer on the rheological behavior of slurry were studied. All the rheological curves obtained under experiment conditions can be correlated with Hershel Bulkley model. Correlated Hershel Bulkley yield stress τ_c can reflect the stability of suspension. The results show that τ_c of A1N slurry is low when the volume fraction of dispersant is 2.5%; τ_c increases with the increase of solid loading; τ_c is the lowest when the milling time is 4 h in the experiments. The viscosity of slurries decreased sharply with the increase of the R ratio (plasticizer/binder), the rheological behavior of aluminum nitride slurries were improved obviously.