Researchers at HRL Laboratories have recently demonstrated a means to additively 3D-print ceramics with a use of a resin that pushes way present limits of ceramic processing while overcoming temperature resistance and brittleness.
Why ceramics are so important
Ceramics components can withstand outrageous amounts of pressure as well as heat that would destroy components made out of metals and plastics. Ceramic components are regularly used in the manufacture of jet engines and can also be found in the brakes of top-of-the-line mountain bikes as well as brakes in Ferraris as well as a host of other super-cars stretching all the way into the realm of professional racing circuits like Formula 1.
The heat and pressure applied to the slowing a car traveling at speeds over 200 mph is fantastic and one of the reasons that ceramics are the norm.
However, it’s for this reason that the production of ceramics by 3D-printing has proven so difficult, and the end product has not offered the strength and heat-resistance that one associates with ceramics. Rather, the end-product has had the opposite qualities when it comes to rigidity and strength, that is until now.
New process produces unheard of success in ceramic printing
The techniques that the team at HRL Laboratories have used to throw a spanner into the limitations of 3D-printing of ceramics were detailed in the Jan 1 journal Science.
“3D printing is a very important new capability, but so far, most materials that can be printed are not high-performance engineering materials,” said study co-author Tobias Schaedler, a materials scientist at HRL Laboratories in Malibu, California. “We wanted to figure out 3D printing of a high-temperature, high-strength ceramic.”
He and his team have done just that by combining polymer chemistry and UV light.
3D-Printing of ceramics has proven difficult in the the past owing to the high heat needed to fuse the printed ceramic particles together. Lacking proper fusing, the printed ceramics are quite porous and its these pores that lead to cracking. In traditional 3D-printing of ceramics powder-based precursors have been layered on top of each other just as an ink jet printer would do with ink on a page.
Rather than relying on powders, Schaedler and his colleagues began with a resin containing silicon, carbon and oxygen. Prior to the “printing” the team shone a spectrum of ultraviolet light beams onto this resin making it harden where the light shone through the material. After laying down the designed shape, the object is heated to 1,000 degrees Celsius in inert argon gas to produce a nearly flawless ceramic.
1,000 degrees Celsius in inert argon gas, drives off any remaining volatiles, leaving behind a pure ceramic part
The new technique is somewhere between 100 and 1,000 times faster that current techniques used to print ceramics and electron microscopy showed little porosity and no surface cracks in the printed objects. This lack of porosity made the crated silicon carbides as much as ten times stronger that presently available ceramic foams according to the researchers.
Work is still needed but the technique is groundbreaking
Ceramics, owing to their heat-resistance and strength will likely find their way into any mission to Mars as well as countless other applications including microsensors in microelectromechanical systems according to the researchers in a conversation with LiveScience.
Schaedler also said, “We are working to reinforce our ceramics with fibers,” in an effort to lessen the inherently brittle nature of ceramics.
“We are at the discovery phase. It will take at least five years for an application to be commercialized,” Schaedler said.
