Take the I-40 west from Knoxville for half an hour, turn north on Highway 95, and you’ll soon arrive at a government facility that, had it never been constructed, would have made the world a far different place. Physicist Enrico Fermi once worked here, as did countless other scientists with names less well-known but whose work was no less crucial to our nation’s defense.
That’s because Oak Ridge National Laboratory (ORNL) was home to the world’s first continuously operating nuclear reactor; it supplied the fissionable material that fueled the atomic bomb, a weapon whose use—though devastating—most likely prevented millions of additional war casualties.
Since that infamous day, ORNL has had a far more peaceful mandate. Its motto? Solving big problems.
A quick look at the organization’s website reveals extensive research into an array of these “big problem” areas, among them artificial intelligence, quantum computing, clean energy, cybersecurity, and material development. Scientists have developed better batteries here, found more effective ways to reduce carbon emissions and recycle plastic, and taken the first steps toward decoding the secret language of plants. Simply put, there’s some serious science going on here.
Brian Post has worked at ORNL since 2013 after earning his Ph.D. in mechanical engineering from the Georgia Institute of Technology. Today he leads the Manufacturing Systems Design Group, where he spends much of his time taking 3D printing and other advanced manufacturing technologies in novel, often surprising directions.
For example, visitors to pre-COVID IMTS exhibitions had a chance to ride around in the Strati and then the Olli, two 3D-printed vehicles made possible by Post’s work in large-scale additive manufacturing (AM). He and a team of researchers have continued to improve and help deploy this and other additive capabilities, resulting in meaningful, possibly industry-altering technological shifts.
“Oak Ridge hosts thousands of visitors a year, with a majority representing individual companies,” said Post. “Of these, approximately 50 enter into a cooperative research and development agreement (CRADA) with my team. We work with them to solve challenges, develop fundamental solutions, and push the technology forward. I’m proud to say that we’re definitely punching above our weight when it comes to these industrial partnerships.”
Such partnerships are a two-way street, he added. “They’re a key lifeline for us to know which way to push our technology development. For instance, an industrial pull in a certain direction or toward a specific application area gives us insight. It keeps us connected to what industry needs and keeps us working at a pace that’s relevant for the stream.”
It also supports the guidelines outlined by the Department of Energy (DoE), which funds much of ORNL’s work. The first of these is to help reduce industrial energy usage, an effort largely focused on lightweighting, increased fuel efficiency, and developing more efficient manufacturing processes. Second on the list is to support the administration’s goals of carbon reduction and greener technology spaces, followed by helping American companies be more competitive in the global marketplace, which Post said means “working hand in hand with our industrial partners to develop technologies that benefit the United States.”
“We’re in the business of helping American companies succeed,” he noted. “We’re also stewards of public funds intended to empower American industry—to make them more competitive and achieve success through advanced manufacturing techniques.
It’s delivering significant results. Post noted that, overall, his group has generated more than one billion dollars of industrial impact. Prior to the development of DoE’s 110,000-sq.-ft. Manufacturing Demonstration Facility (MDF)—a user facility at ORNL—in 2012, the largest commercially available 3D printer had deposition rates of five cubic inches of material per hour and produced parts no larger than a suitcase.
Thanks to collaborations with companies such as Lincoln Electric, Cincinnati, GKN Aerospace, Lockheed Martin, and dozens of other manufacturers—many of which assigned employees to work alongside Post and his ORNL team for extended periods—large-scale additive manufacturing (LSAM) has become almost commonplace. “There are now around several dozen companies active in this space, where before there were none,” he said.
Their work is not entirely in additive, nor is it all large-scale. Other notable projects include the development of a fuel canister bracket made of refractory metal for the Browns Ferry Nuclear Plant in Alabama. They’ve produced Inconel 718 turbine blades for hot-fire testing, and found ways to repurpose rare earth magnets. Meanwhile, a newly developed robotic additive manufacturing and compression molding (AMCM) process, which Post said produces fully dense composite parts with excellent material properties, promises to support automotive-level production rates.
In addition, they’ve done extensive research into microstructural control during 3D printing. “By controlling the local rates of cooling and the way in which we introduce energy during electron-beam, powdered-metal printing, we were able to modify the grain structure inside a monolithic block to replicate the Mona Lisa,” he said. “You can only see it on a micrograph, but it’s pretty cool.”
On the opposite end of the AM spectrum, Post has an interest in large-scale concrete printing, an activity that falls squarely under the DoE’s goals of energy efficiency and green manufacturing. “Concrete production accounts for a large share of industrial energy consumption, so if there’s a way to use less of it, we’ll save a significant amount of energy while also cutting CO2 emissions, which account for roughly 8 percent of the global footprint.”
As many in the AM industry have found, topology optimization serves to reduce material use while increasing part strength, and concrete structures are no different. The challenge then becomes how to build these structures on a scale far surpassing that of 3D-printed cars and compression molds. Doing so not only requires a truly massive machine tool, but one that a construction company can deploy in the field without too much cost or effort.
“Some residential house builders have used big gantry robots for this application, but they’re limited in size,” said Post. “We developed something similar to the cable-driven skycams you see at sporting events, but instead of a camera, it would have a concrete extruder. Such a design would support quick setup onsite, even in remote locations, and require minimal infrastructure. We named it the SkyBAAM.”
Although SkyBAAM (big area additive manufacturing) technology is not quite ready yet to take flight, Post’s team has constructed a prototype system and built some small structures with it. They also began developing alternative cement formulations that are less energy intensive and generate lower amounts of CO2. “Instead of relying on hydraulic reactions as in Portland cement, we use a binder that cures by absorbing carbon dioxide from the atmosphere.”
Post earned his undergraduate degree in mechanical engineering at Purdue University. At that time, he planned to pursue a career in surgical robotics. A summer internship at ORNL with professor Lonnie Love changed his plans. While working with a robotics group making human exoskeletons, ship motion simulators, and omnidirectional vehicles, Post got involved in a DARPA’s “Revolutionizing Prosthetics” project.
“This was around 2008 or so, and far too many soldiers were returning from Iraq and Afghanistan with missing limbs,” he said. “DARPA was very interested in developing the next generation of prosthetic device, something that would give warfighters greater capabilities than a stick with a hook on it. So, we started working on small-scale hydraulic stuff, with tiny actuators and pumps and accumulators. We built an elbow joint that could curl 60 lbs every six seconds and a finger that could curl 25 lbs, but we soon found ourselves designing things that we couldn’t make anymore.”
The team turned to direct metal laser sintering (DMLS) and other additive technologies to produce the parts that traditional manufacturing could not. That, said Post, was his introduction to 3D printing. He never turned back. “When I finished my Ph.D. and came back from Georgia Tech, I went to Oak Ridge and began looking for ways to use my robotics knowledge to improve the state of additive systems.”
ORNL supports six of the seven leading AM technologies. When asked which is his favorite, Post admitted to some bias toward hybrid manufacturing, which he spends most of his time on. He’s quick to note that this encompasses two distinct technologies—the hybrid CNC machine tools offered by Mazak, DMG Mori, and Okuma (all are partnering with ORNL), which combine additive and subtractive manufacturing in the same piece of equipment, as well as hybrid processes that allow the manufacturer to shuttle work back and forth between complementary machinery quickly and accurately.
“If we can figure out how to use these systems effectively, it’s going to open a lot of applications, especially in the casting and forging industry, where the U.S. has lost so much of our capabilities over the past few decades,” he said. “If we can reshore some of that by investing in advanced manufacturing technology, I think we’ll enjoy significant value.”
Additive or not, it’s this last point that has captured much of Post’s attention, and rightfully so. “We’ve lost so much, not just in casting and forging but in other manufacturing areas as well. When you offshore an entire industry, you don’t just lose the capital equipment and the building infrastructure; you lose the people and the knowledge they carry. To rebuild that isn’t easy. We need to train people in advanced manufacturing technologies, create new industries built around those services, and then provide long-term support to the industry as a whole; we need to make American production more cost-effective and agile than ever before. There’s a huge opportunity there, but more importantly, it’s the right thing to do for our country.”