Ceramic forming and powder preparation
The forming process is of utmost importance for turning selected raw materials into a high quality ceramic with the desired properties. This forming process must provide a homogeneous green body for the subsequent sintering process. The green body is characterized by both an even distribution of the raw material particles without any hard agglomerates as well as a homogeneous and high density.
The preparation of the ceramic bodies, slurries and granules plays a decisive role in the production of ceramics alongside the forming process itself. Every forming process requires specific consideration due to the use of specialized binder and additive systems.
At the Fraunhofer-Center HTL, standard measurement methods for particle size distribution and "Zeta" potential, not only in diluted suspensions, but also application-oriented in highly concentrated slurries can be used for the improvement of the preparation process and for the selection of the best additives. These methods are supplemented by rheological measurement methods (oscillation and rotation), measuring extruders and both optical and electron microscopy. All the chemical and physical properties of raw materials that are important for processing, forming and the properties of the ceramics can be analyzed beforehand. After the forming process, special methods for the characterization of green compacts are available at the HTL.
At Fraunhofer-Center HTL, all common forming processes for ceramics are available (dry pressing, isostatic pressing, or wet pressing, slip casting, tape casting, extrusion, etc.). The range of forming processes is completed by new types of 3D printers, with which it is possible to construct complex ceramics through additive design, and a high-quality 5-axis milling machine for green body processing and finishing.
In order to enable fast prototyping with metals and ceramics, the Fraunhofer-Center HTL also offers the forming processes (in particular the additive forming process) as a service independently of projects for material and process development.