Talks and Poster Presentations (without Proceedings-Entry):
J. Homa, J. Stampfl:
"Fabrication of Cellular Ceramics Structures by Gel-Casting and Rapid Prototyping";
Poster: Junior Euromat 2006,
Gel-casting is a novel forming process for making complex-shaped ceramic and metallic parts. A low viscosity slurry, consisting of ceramic or metallic powder, an aqueous or non aqueous solvent, dispersant and two organic monomers, are poured into a mold and polymerised in situ. The obtained green body is then dried, debinded and sintered.
Gel-casting moulds are in contrast to slip casting non-porous moulds and they can be fabricated by a wide range of materials. Moulds are usually made of metal, plastic, glass or wax whereas the mould complexity is often limited by the fabrication process.
If conventional techniques as milling is used to make the moulds, the complexity of the parts is lower than injections moulded parts, because the material is very brittle and therefore undercuts can not be realized.
But by the combination of Rapid Prototyping and Gel-casting highly complex ceramic parts can be produced, which can not be fabricated by any other ceramic forming technique.
A 3D model is designed on the computer and the mould is build up out of wax and thermoplastic material by a rapid prototyping machine. A soluble wax is used to support overhangs, so that this kind of forming process can be used to fabricate highly complex cellular structures such as certain diesel particulate filters or highly porous structures.
Created from the Publication Database of the Vienna University of Technology.