Ceramic processing via thermoversible gelcasting is enabled by the rapid, thermally reversible gelation of a set of triblock copolymer solutions. The triblocks behave as low viscosity solutions at temperatures above about 60°C, but behave as strong elastic solids at temperatures below 35°C. The gel structure forms instantaneously by the aggregation of the end blocks of the copolymer molecules to form an elastic gel. This transition is maintained even when the gels are filled with high volume fractions of solid particles. Therefore these materials can be used to form ceramic objects with complex shapes via simple gelcasting. Processing can be optimized when the triblock endblock is of an appropriate length. If the block length is too short, the relaxation time of the gel is too low, and details in ceramic pieces are not retained. Alternately, too long an endblock raises the processing temperatures and increases the viscosity of the ceramic slurry. |
