Ceramic 3D Printing

Additive manufacturing (AM) of ceramics is a technology that addresses many limitations of traditional ceramic processing. Conventional methods often require complex tooling, long lead times, and offer limited design flexibility—particularly for intricate geometries or internal features. In contrast, AM enables the direct fabrication of complex, high-performance ceramic components with minimal material waste, no molds, and significantly reduced development times. In the last decade, much research has been centered on different additive manufacturing technologies for ceramics, some of which have already been commercialized. Some of the popular ceramic AM methods are Vat Photopolymerization, Fused Filament Fabrication, Selective Laser Sintering, and Binder Jetting, with each of them having advantages or disadvantages in terms of cost, ease of use, resolution, final part quality, and other factors.

Vat Photopolymerization 

Vat photopolymerization is a well-established family of AM techniques characterized by the layer-by-layer curing of liquid photoactive resins through light-induced polymerization. A very popular technique within the VPP family is Digital Light Processing (DLP). Here, light from a projector is selectively directed onto the transparent bottom of the vat, where it cures the resin only in the desired regions. A schematic representation is shown in Figure 1 (left).

Figure 1: Left: Schematic representation of DLP process. A new layer can be seen being cured by the light projection system. Thickness of a single layer is exaggerated. Right: Timeline of a VPP additively manufactured part. Orange part represents plastic, while gray part represents ceramic.

While this process is mature for plastics, it can be adapted for ceramics by incorporating ceramic powders into the resin, forming ceramic slurries. These slurries, typically composed of about 50 vol.% ceramic particles, are printed similarly to standard resin systems. The resulting green parts are composites of ceramic particles within a polymer matrix. To obtain dense, monolithic ceramics, the printed parts require post-processing—specifically debinding and sintering. Debinding involves slowly heating the green part to thermally decompose and remove the organic matrix. This step must be carefully controlled to prevent crack formation caused by internal gas evolution. After debinding, the ceramic body is sintered using conventional thermal treatments to achieve densification. Figure 1 (right) shows the timeline of a manufactured part. The top object shows the part immediately after printing, with ceramic particles embedded in a plastic matrix. In the debinding stage, the plastic is removed, leaving behind only loosely adhered ceramic powder. Finally, in the sintering step, the powder is densified into a monolithic object.

Formulating suitable ceramic slurries presents several challenges due to the interplay of multiple critical parameters. The organic resin must exhibit a high photopolymerization rate to ensure rapid and complete curing of each layer, which restricts the choice of monomers—acrylates and methacrylates are typically used. At the same time, achieving high ceramic content is essential for minimizing shrinkage and cracking during sintering, but high particle loading leads to increased viscosity, which can hinder the printing process. Therefore, balancing photoreactivity, ceramic content, and rheological properties is key to producing high-quality ceramic suspensions. With carefully designed formulations, a wide variety of ceramic materials can be processed using vat photopolymerization.

Figure 2: External (left) and internal (right) view of the CeraFab S65 machine.

In the K9 department, we have access to the CeraFab S65 (Lithoz, Austria) additive manufacturing system, as can be seen in Figure 2. Technical parameters of the machine are shown in Table 1. The machine uses blue light (460 nm) for curing of the layers. It enables processing of highly viscous slurries due to the vat recoating system. The machine enables the creation of extremely detailed and complex objects, as seen in the parts shown in Figure 3 (left), while the sintered parts can be seen in Figure 3 (right).

Table 1: Technical parameters of the CeraFab S65 machine.

 Figure 3: As-printed parts on the build platform (left). Sintered parts (right).