Breakthrough made in 3D ceramic printing

RESEARCHERS in California, US, have developed a new kind of resin that can be 3D-printed and fired to create high-strength, full-density ceramic components.

Ceramics have extremely high melting points, are environmentally stable and unreactive. However, unlike metals and polymers, they are difficult to manufacture complex parts from, because they cannot be easily cast or machined. 3D printing or the additive manufacturing of ceramics increases the complexity of parts that can be produced, but current techniques are very slow or introduce significant porosity, which makes parts brittle. The team at HRL Laboratories, led by Tobias Schaedler, says its new technique overcomes these difficulties.

Chemical engineer Zak Eckel and chemist Chaoyin Zhao have developed a UV-curable siloxane-based resin. It is made from (mercaptopropyl)methylsiloxane and vinylmethoxysiloxane, with a UV free-radical photo initiator, a free-radical inhibitor, and a UV absorber. Shapes are formed layer by layer by focussing UV light onto the liquid resin, which hardens into the desired shape where the light touches it.

This solid shape is then fired at around 1,000?C in an argon atmosphere, converting it into silicon oxycarbide. The components resist shrinking during the firing process and are as dense and strong as conventional ceramics. The fired pieces can withstand temperatures of 1,700?C.

The team says that the process could be used to create a wide variety of parts, from large components in jet engines to tiny parts in microelectromechanical systems.

“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 Schaedler.

The team is now looking for commercial partners to develop the technology.

Science DOI: 10.1126/science.aad2688