Focus

Net-shape forming techniques: Gel-Casting

The transport and energy industry it is more and more in need of complex ceramic parts with high level of accuracy (blades, rotors, turbines, etc...) able to stand harsh operating conditions while retaining the shape. This can be accomplished if the ceramic bodies can be produced in an easy and economic way. Gel-casting can be a valid alternative to injection molding for the production of large, complex-shaped components requiring highly uniform properties. This highly reproducible forming technique is not requiring significant changes in the equipment generally used in ceramic processing. The core of the technique is an organic monomer solution that can be polymerized to form a strong, cross-linked polymer-solvent gel. The monomer solution provides a low-viscosity vehicle that combined with the ceramic powder forms an highly fluid slurry that can be easily poured into moulds to form complex shapes. Recently, following the so-called "green chemistry principle" ISTEC is studying to replace the chemicals generally used for this process (metacrylamide, metilen-bysacrylamide, etc) with more environmental friendly natural polymers (agarose, agar-agar, k-karragenine).