Journal of the American Ceramic Society, Vol.97, No.3, 725-732, 2014
Fabrication of Barium Strontium Titanate ( Ba0.6Sr (0.4) TiO3) 3D Microcomponents from Aqueous Suspensions
This study reports on the fabrication of BST (Ba0.6Sr0.4TiO3)-based 3D microcomponents through an aqueous colloidal approach. The BST powder was synthesized by solid-state reaction assisted by thermal analysis and XRD diffraction. Well crystalline cubic BST single phase was obtained upon heat-treating the precursor powder mixture at 1200 degrees C-1250 degrees C. The reactivity of the BST powder toward water was evaluated by the changes in pH and concentration of leached ionic species along aging time. Hydrolysis reactions were suppressed by chemisorbing a suitable phosphate-based protective agent and enabled an excellent dispersion ability to be achieved. Aqueous suspensions with solids loadings as high as 50vol% that are stable against hydrolysis for several days could easily be prepared from the surface-treated BST powder in aqueous solutions of an epoxy resin. After adding a suitable hardener, the colloidal suspensions could easily be cast into soft silicon rubber molds to obtain homogeneous and high dense green BST bodies.