Material characterization for Fused Deposition of Ceramics

Fused Deposition of Ceramics (FDC) is a technique to produce ceramic components, based on the extrusion of powder/binder filaments to form layer by layer three dimensional objects. Filament materials must contain a high content of ceramic powder to prevent shrinkage on thermal treatments as debinding and sintering, without compromising adequate theological properties during the extrusion process. This research aims at developing an alternative FDC system not requiring the use of precursor filaments. Throughout this process, material in pellet or granule form is fed into a chamber where it is softened. Pressure forces the material down a chamber and out through a nozzle tip. In this work, feedstocks containing different ceramic/binder compositions were prepared. Two kinds of alumina powders with different particle sizing characteristics were used and mixed with a commercial binder based on polyolefin waxes. Thermal and rheological analyses together with scanning electron microscopy were used to characterize the feedstocks, as well to select both the optimized feedstock and processing conditions.