The Critical Materials Institute (CMI) at the U.S. Department of Energy's Ames Laboratory is using 3D printing to invent an array of new alloys to be used in the creation of clean energy.

The goal is to find substitutes for materials essential for clean energy technologies that are also at risk of being in short supply.

The DOE is also partnering with Cincinnati Inc. to develop 3D printer capable of printing polymer components up to 10 times larger than currently producible, and at speeds 200 to 500 times faster than existing machines.

CMI scientists are using a LENS MR-7 3D printer, manufactured by Optomec, instead of traditional casting methods to streamline the process of bulk combinatorial materials research, quickly producing a large variety of alloys.

"Metal 3D printers are slowly becoming more commonplace," CMI Principal Investigator Ryan Ott said. "They can be costly, and are often limited to small-scale additive manufacturing in industry. But for us, this equipment has the potential to become a very powerful research tool. We can rapidly synthesize large libraries of materials. It opens up a lot of new possibilities."

The LENS MR-7 uses models from CAD software to build layers of metal alloy on a substrate via metal powders that are melted by a laser. Four chambers supply metal powders to the deposition head that can be programmed to produce a nearly infinite variety of alloy compositions. The printing occurs in an ultra-low oxygen glove box to protect the quality of highly reactive materials.

 In a recent demonstration run, the printer produced a one-inch long, 0.25-inch diameter rod of stainless steel in 20 seconds.

Researchers are hoping to overcome some of the obstacles of traditional combinatorial materials research.

"The problem is that it's been typically limited to thin film synthesis," Ott said. "These thin film samples are not always representative of the bulk properties of a material. For example magnetic properties, important to the study of rare earths, are not going to be the same as you get in the bulk material."

Combined with computational work, experimental techniques, and a partnership with the Stanford Synchrotron Radiation Lightsource (SSRL) for X-ray characterization, scientists at the CMI will be able to speed the search for alternatives to rare-earth and other critical metals.

"Now we have the potential to screen through a lot of material libraries very quickly, looking for the properties that best suit particular needs," Ott said.

The CMI seeks ways to eliminate and reduce reliance on rare-earth metals and other materials critical to the success of clean energy technologies. The DOE's Energy Innovation Hubs are integrated research centers that bring together scientists and engineers from many different institutions and technical backgrounds to accelerate scientific discovery in areas vital to the country's energy security.

The Ames Laboratory is a DOE Office of Science national laboratory operated by Iowa State University. Ames Laboratory creates innovative materials, technologies and energy solutions.