Jan 1, 2016 | By Benedict

HRL Laboratories has developed a new technique for 3D printing ultra-strong ceramic materials which can withstand temperatures in excess of 1,400 degrees Celsius. The company believes the process could soon be used in the aerospace industry.

3D printed ceramics have been around for some time now, with companies like Vormvrij 3D and Deltabots developing their own ceramic 3D printers and 3D printed ceramic products. But whilst many existing ceramic 3D printers utilize a simple FDM-style process, HRL Laboratories are using a more precise stereolithography technique to produce incredibly detailed, strong and heat-resistant ceramic 3D prints.

“We have a pre-ceramic resin that you can print like a polymer, then you fire the polymer and it converts to a ceramic,” said Tobias Schaedler, senior scientist at HRL. “There is some shrinkage involved, but it's very uniform so you can predict it.”

By developing a new printable resin made of “preceramic polymers”, HRL seems to have hit upon a ceramic 3D printing method which sidesteps the common pitfalls associated with ceramic 3D printing. Typical techniques for 3D printing ceramics cannot produce particularly complex parts, with prints often susceptible to cracks and fractures. Most ceramic 3D printers are also limited to "oxide ceramic materials” with low melting points. Because of the precise stereolithography process used, HRL can 3D print dense and durable ceramic parts, resistant to the highest temperatures.

“We’ve invented a resin formulation compatible with stereolithography / 3D printing which, after 3D printing, can be fired to produce a fully dense ceramic part,” explained Zak Eckel, an engineer at HRL. “This is an amazing breakthrough, as it allows us to produce freeform ceramic parts of extremely strong and temperature-resilient ceramics without any machining, casting or impaction. We can leverage many of the benefits of 3D printing, the ability to create complex 3D parts, with a highly useful engineering material.”

Parts printed using HRL’s $3000 ceramic 3D printer do not look like ceramic 3D prints at all, more closely resembling plastic parts. The special resin they use contains all the molecules you need to form a tough ceramic. Layers of the resin are carefully etched with a UV light, which fuses monomers into polymers. The plastic-like print is then forged in an oven at 1,000 degrees Celsius in the presence of argon gas, which removes the excess chemical groups and leaves behind only the strong ceramic framework.

Using electron microscopy to analyze the end product, the researchers detected no porosity or surface cracks. Further tests reveal that the ceramic material can withstand temperatures of 1,400⁰ Celsius (2552⁰ Fahrenheit) before experiencing cracking and shrinkage.

A curved 3D printed ceramic lattice

A 3D printed leading edge

HRL has been able to form what could be the first ever 3D printed silicon carbide ceramics, and the team believes it could print several more kinds by appropriately adjusting the makeup of the ceramic-plastic resin. The company sees its crack- and heat-resistant ceramics as an ideal material for numerous high-temperature applications, such as in hypersonic vehicles and jet engines. This method could help designers to make lots of special small parts that are capable of resisting the heating and high temperatures generated by the exhaust during takeoff.

“If you go very fast, about 10 times speed of sound within the atmosphere, then any vehicle will heat up tremendously because of air friction,” said Schaedler. “People want to build hypersonic vehicles and you need ceramics for the whole shell of the vehicle.”

Thanks to the new approach, HRL Labs researchers have 3D printed two classes of useful ceramic parts - large, very lightweight lattice structures that could be used in heat-resistant panels and other exterior parts for airplanes and spacecraft, and small, intricate parts for use in electromechanical systems or in components of jet engines and rockets.

The group has now funding from DARPA, says Schaedler. "The method brings us closer to the goal of being able to 'engineer in' desired material properties that generally are not found together, such as strength and low density or low weight, and to craft these materials into complex shapes,” said Stefanie Tompkins, director of the Defense Science Office at the Defense Advanced Research Projects Agency (DARPA).

Rocket and satellite designers looking for small, heat-resistant parts could soon turn to HRL’s ceramic 3D printing process, once further testing has been carried out. A paper detailing the company’s findings has been published in Science Magazine.

 

 

Posted in 3D Printing Application

 

 

Maybe you also like:


   


Stéphane Hocquet - BCRC wrote at 1/11/2016 12:06:14 PM:

I wonder if they can obtain a dense part, simply a cube 3 x 3 x 3 cm³, with that kind of technology. I suppose they can only obtain a part with no crack only if this part is build with porosities (like the examples they proposed in the video). In that case, there is place for the evolved material to be gently eliminated during sintering. But actually, no rapid manufacturing or prototyping technology exists that allows dense ceramic part (as a cube) with larger dimensions to be built without any default;

pizzaslice wrote at 1/2/2016 2:35:44 PM:

There are various different AM processes to create ceramics; stereolithography, lithography-based ceramic manufacturing, freeze-form extrusion, powder based selective laser sintering, slurry based selective laser sintering, fused deposition of ceramics, powder bed and inkjet 3d printing, slurry based and inkjet 3d printing, direct inkjet printing, laminated object manufacturing and direct ink writing. Some of these technologies, like stereolithgraphy have been studied for years. There are others, who can print these parts or are very close to printing these parts as well.



Leave a comment:

Your Name:

 


Subscribe us to

3ders.org Feeds 3ders.org twitter 3ders.org facebook   

About 3Ders.org

3Ders.org provides the latest news about 3D printing technology and 3D printers. We are now seven years old and have around 1.5 million unique visitors per month.

News Archive