The paper presents a way to fabricate design prototypes for ceramic diesel particulate cross flow filters by a solid free form fabrication process. Due to the strong undercuts of the structure fugitive wax molds have to be used. The wax mold, which is either produced by rapid prototyping or by stacking milled wax layers, is filled with a ceramic slurry. Gelcasting, a ceramic forming technique for complex shapes, was used in combination with the fugitive wax molds to produce monolithic cross flow diesel particulate filters (DPF). The gelcast cross flow filters have dimensions from 20 × 30 × 28 mm³ to 90 × 90 × 40 mm³ and wall thickness from 0.4 to 1 mm. The material used is recrystallized silicon carbide (RSiC), because it has an inherent porosity, good thermal shock resistance and a non-shrinking sintering behavior. Furthermore the binder removal and the sintering are discussed.

Keywords: Gelcasting, DPF, RSiC, Ceramics, Rapid Prototyping.