A 3D-printed ceramic lattice. (Image courtesy of HRL Laboratories.)
Ceramic materials are ideal for a wide range of applications from jet engine components to intricate microelectromechanical parts.
Unfortunately, because they cannot be cast or machined easily, ceramic parts are generally more difficult to process compared to polymers or metals.
However, a new approach for producing ceramics using additive manufacturing overcomes the traditional limitations on ceramic processing.
3D Printing Ceramics
Ceramic parts are traditionally consolidated from powders by sintering. This inevitably leaves residual porosity in the parts, limiting their strength as well as their range of achievable final shapes.
The new approach utilizes a preceramic monomer resin which can be 3D-printed into parts of virtually any shape or size. Using a laser to raster the geometry of a part in the resin cures that portion of the resin into a polymer. Once cured, the resin is then fired to yield the final product: a high-strength, fully dense ceramic part.
Left: A laser is used to raster part geometry in preceramic resin. Right: a printed piece of resin before final curing. (Images courtesy of HRL Laboratories.)
No significant shrinkage has been observed as a result of the firing process and once fired, the parts show exceptional thermal stability.
A silicon oxycarbide microlattice fabricated using this process exhibited ten times the strength of similar ceramic materials. It can also withstand temperatures in excess of 1700°C (3092°F).
"With our new 3D printing process, we 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," said Dr. Tobias Schaedler, program manager at HRL Laboratories.
Check out the video below to see just how tough these 3D-printed ceramics are:
Applications for 3D-Printed Ceramics
Schaedler and his colleagues envision applications for their process in the aerospace, electronics and packaging industries.
At this point the most salient concerns are those regarding quantity rather than quality. The promotional video for the process mentions that it can take anywhere from several hours to several days to complete. The company also hints that it could substantially reduce that time, which would be crucial to integrating this process into manufacturing on an industrial scale.
For more information, check out the team’s research paper “Additive Manufacturing of Polymer Derived Ceramics”
in the January 1st
2016 issue of Science