The extremely high melting point of many ceramics adds challenges to additive manufacturing as compared with metals and polymers. Because ceramics cannot be cast or machined easily, 3D (three-dimensional) printing enables a big leap in geometrical flexibility. We report preceramic monomers that are cured with ultraviolet light in a stereolithography 3D printer or through a patterned mask, forming 3D polymer structures that can have complex shape and cellular architecture.

These polymer structures can be pyrolyzed to a ceramic with uniform shrinkage and virtually no porosity. Silicon oxycarbide microlattice and honeycomb cellular materials fabricated with this approach exhibit higher strength than ceramic foams of similar density. Additive manufacturing of such materials is of interest for propulsion components, thermal protection systems, porous burners, microelectromechanical systems, and electronic device packaging.

Ceramics are much more difficult to process than polymers or metals because they cannot be cast or machined easily. Traditionally ceramic parts are consolidated from powders by sintering, which introduces porosity and limits both achievable shapes and final strength. “With the new 3D printing process can take full advantage of the many desirable properties of this silicon oxycarbide ceramic, including high hardness, strength and temperature capability as well as resistance to abrasion and corrosion. Says program manager Dr.Tobias Schaedler.

The novel process and material could be used in a wide range of applications from large components in jet engines and hypersonic vehicles to intricate parts in microelectro-mechanical systems and electronic device packaging.