Rheological Behavior of Alumina Aqueous Suspension for Extrusion Gelation Freeform Fabrication
Extrusion gelation freeform fabrication (EGFF) is a new solid freeform fabrication technique to fabricate ceramic parts. The study of ceramic suspensions rheological behavior is essential to a better understanding of parts fabrication through EGFF process. In this paper, the effects of dispersant concentrations, solids loading and binder composition on the rheological behavior of alumina suspensions were examined. The optimal amount of dispersant was found to be about 0.1 wt.%. The suspensions with 50 vol.% alumina and 1wt.% sodium alginate show shear thickening behavior. Such behavior is unfavorable for extrusion gelation freeform fabrication. By addition of PVA or styrene-acrylic latex, the rheological behavior of suspensions was changed. The addition of PVA or latex has a great effect on the viscosity of the suspensions and the type of their rheological behavior. The ceramic suspensions with PVA or latex were found to be shear thinning more suitable for EGFF.
Wei Pan and Jianghong Gong
Z. Y. Yu et al., "Rheological Behavior of Alumina Aqueous Suspension for Extrusion Gelation Freeform Fabrication", Key Engineering Materials, Vols. 336-338, pp. 984-987, 2007