Interpenetrating composites offer a three-dimensional reinforcement geometry and are an established reinforcement concept for MMC composites. Additive manufacturing processes offer the advantage that, in contrast to conventional preforming processes such as freeze casting, the ceramic preform can be freely defined globally and thus adapted to the respective loading situation.

In this contribution, ceramic preforms of different geometries - and also of different filling grades representing different grades of open porosity - were produced by FDM. It was shown that a stable printing process could still be realized even with a nozzle diameter of 0.4 mm, thus generating correspondingly filigree structures in the FDM, which are necessary for the production of interpenetrating composites.

By means of gas pressure infiltration, it was shown that the open porosity of the structures is maintained after sintering and that the preforms are very well suited for the fabrication of interpenetrating composites.