PROCESSING OF DIATOMITE FROM COLLOIDAL SUSPENSIONS - TAPE CASTING

The microstructural development of ceramic tapes is influenced by the properties of the casting suspensions from which they are produced. Th e aim of the present paper was the study of the relevant relationships between the rheological properties of as formulated ceramic suspensio ns, and the resultant microstructures of as cast and sintered tapes. T he material system studied consisted of diatomite powder (50 wt-%) dis persed in water by the use of a deflocculant (0.7 wt-% Dolapix). The t ape casting slips were prepared by adding a total amount of similar to 10 wt-% of suitable additives (binder, thickening, and antifoaming ag ents). Particle size distributions and surface chemistry were found re levant in determining tape casting performance, as well as the green a nd final microstructure of the bodies. Porous layers, having controlle d porosity and pore size distributions, were obtained for potential ap plications infiltration systems.