Making 3D Metal Magic
K.2, L3, and B8. Only a devoted “Star Wars” fan would recognize that Nanci Hardwick has given droid names to the 3D printers leaving her factory. And never mind the fact that they existed a long time ago in a galaxy far, far away, it’s entirely fitting that Hardwick would name her team’s brainchildren after them. Both technologies are, after all, equally improbable.
“You stand in front of the machine and think, ‘I see it happening, but my brain tells me this isn’t possible,’” said Hardwick. “It’s mesmerizing to watch.”
A Significant Force
Hardwick is the CEO of Meld Manufacturing Corp. in Christiansburg, Va., and she’s talking about the company’s 3D-printing process of the same name (MELD). The company’s solid-state additive manufacturing technology is “almost magical” in its operation, she enthused, and it is able to use a veritable cornucopia of metal feedstocks to build some equally magical workpieces.
The industry is taking notice. For instance, the U.S. Army recently invested millions in a pair of large-format machine tools equipped with MELD print heads. One of these lays claim to the title of “World’s largest metal printer,” and will be used to build jointless hulls up to 9.1-meters long for next-generation combat vehicles. The Army also certified MELD as a replacement for Ti6-4 titanium forgings, and, in another “world’s largest” feat, a MELD-equipped metal printer built an aluminum cylinder measuring 3.05 meters in diameter.
“Although we’ve demonstrated the ability to print with a variety of feedstocks, including different shapes and sizes of metal powder, leftover chips from the machining process, and even recycled scrap, our standard, off-the-shelf printers use commercially available metal bar stock,” Hardwick noted. “You might think of it as a mechanical pencil, but one that requires far more force to push the lead out.”
The “lead” in this case could be made of 316L stainless steel, Inconel 625, 6061 aluminum, CuW (copper-tungsten), or any other metal that plastically deforms when subjected to vertical downforce coupled with rotational shear (which is practically all of them). As for the amount of pressure needed to “write” with a metal bar, Hardwick said it’s significant, although not enough to exceed the structural integrity of a well-constructed CNC machining center. The applied force varies depending on the size of the machine, type of feedstock, and desired deposition rate, according to Hardwick, adding “but figure thousands of pounds.”
This isn’t Hardwick’s first CEO rodeo. In 2007, she took the reins at Aeroprobe Corp., a designer and manufacturer of air data and flow measurement systems formed in 1994. “The company was originally focused on the types of test and validation equipment used in wind tunnels, for example, and ground-based testing of jet engines,” Hardwick said. “I wanted to take all those sensors, plumbing, and computers, miniaturize it, and stick it on an aircraft. I knew there was a need for better instrumentation, especially with unmanned air vehicles [UAVs], and doing so would provide real-time data about flight and weather conditions.”
Previously, Hardwick worked on conceptual aircraft designs for UAVs. She saw signs that the industry was quite literally about to take off and felt that such advanced capabilities were crucial to UAV success, so Hardwick pitched her idea to Aeroprobe’s management. The answer was a polite, “No, thank you. But maybe you’d like to buy the company?”
She promptly took the company up on the offer and assumed control of it. But she had even bigger plans. In addition to helping Aeroprobe develop new lines of instrumentation for the aerospace, automotive, and wind power industries, Hardwick had her sights set on another project, one poised to grow metal wings and take flight. “I saw an opportunity to take the tremendous amount of expertise we have here and apply it to a specific application,” she explained. That led to the formation of Meld Manufacturing, which became a subsidiary in 2018 and now is poised to be spun off as a separate company in early 2023.
The Long-Term Play
Looking back, Hardwick might be disappointed that self-driving car technology has outpaced air taxis and delivery drones to date, but she has no regrets about her timing. Aeroprobe was well positioned to support the prototype stages of numerous UAV programs that have since moved into production. It’s largely due to this “long play” that the company has an excellent reputation and continues to grow with the market. And given Meld Manufacturing’s numerous patents and endorsements from the U.S. military, it’s likely that a similar story will soon be told about Hardwick’s latest business venture.
That story begins with a meeting at the Army Research Lab in Maryland, where an acquaintance was looking for ways to repair components or even manufacture replacements in a battlefield environment. “He was sending broken car parts and scraps of metal to a company that had developed a mobile, miniaturized atomizer,” she said. “I believe the intent was to use the resulting powder for cold spray deposition, and that they’d had some success but were struggling with a small amount of porosity. So even though we weren’t part of the original project, he sent us a quantity of powder, just to see if we could repair some damaged steel plates.”
Despite the powder being a “mystery alloy,” Hardwick accepted the challenge and soon returned the test plates, good as new. And, while she takes pride in this ad-hoc proof of concept, she’s more excited about its potential uses in third-world countries, where established provisions of high-quality feedstock are in short supply but waste metals are not. Further, Hardwick sees the ability to convert “whatever materials we have, wherever we are” into 3D-printed parts as a steppingstone to interplanetary space exploration. “That would be super cool,” she beamed.
Building the Case
It would be so cool, in fact, that Hardwick raised the notion as part of her sales pitch to the Army during the “giant 3D-printer” selection process referenced earlier. She admits it was far from the deciding factor, but noted that those responsible for the project recognized the ability to print with a wide selection of metals and feedstocks—even those with mysterious pedigrees—would serve to future-proof their investment.
Hardwick’s presentation also explained another key differentiator. As its name implies, there’s no melting with MELD—the metal achieves plasticity but never forms a molten “melt pool” as with laser-, electron-, and arc-based processes. Because of this, there’s neither residual stress nor need for post-build heat treatment or “hipping” (hot isostatic pressing). The grain structure is also much finer than that achievable with even billet, cast, and forged metals, resulting in components that exhibit excellent strength as well as improved resistance to wear and corrosion. Finally, she said, the process itself is faster than competing technologies. It produces less waste, and is performed without the need for shielding gases or sealed build chambers.
Simply put, parts leave a MELD printer ready for finish machining. In the Army’s recent acquisition, even this final handling step is eliminated—the two large-format printers are hybrid machines that combine an Ingersoll three-axis vertical machining center with a MELD deposition head. The good news for the rest of the manufacturing world is that Meld Manufacturing has just released a similar machine, albeit in a much smaller package, dubbed the 3PO hybrid printer.
“One of the Army’s primary goals is to produce monolithic structures that eliminate as many weld joints as possible, as these are vulnerable to rockets and other explosive devices,” Hardwick cautioned. “Regardless, we were the only supplier that checked all the boxes, which is why the selection team unanimously chose Meld for their project.”
Wins like this are nothing new to Hardwick. She took home the Roanoke Blacksburg Technology Council Entrepreneur of the Year award in 2016 for her innovations in unmanned systems and additive manufacturing. At the 2018 R&D 100 Awards, an “international competition that recognizes the 100 most exceptional innovations in science and technology from the past year,” MELD earned a special Market Disruptor award. And during the 2022 Additive Manufacturing Users Group conference, Hardwick and Meld Manufacturing were presented with the Advanced Concepts Award.
When not busy receiving achievement awards or developing novel technologies, Hardwick volunteers—a lot. Former Virginia Governor Ralph Northam recognized Hardwick for her leadership in the community and as a small business owner. She also serves on the governor’s advisory board for Build Virginia, an organization that supports manufacturing workforce development, as well as the editorial advisory board of the regional magazine Valley Business Front.
She previously had leadership roles on the Roanoke Blacksburg Technology Council, the United Way’s United in Caring Fund, Onward NRV (the New River Valley Economic Development Alliance), Virginia Tech’s CRC Community Impact Program, and the New River Community College Foundation and Lyric theatre. She also was a founding board member of the Roanoke Blacksburg Innovation Network, an adult literacy tutor for the Literacy Volunteers of America, and created the Ridge and Valley Chapter of the AUVSI, which is described as the world’s largest nonprofit organization devoted exclusively to advancing the unmanned systems and robotics community.
“I’ve been quite lucky to have had these opportunities,” Hardwick said. “I live in a small community in the mountains of Virginia. It’s very rural, and we have some challenges here, so I’m just grateful I can help. And I loved teaching people to read—I mean, how can you get more impactful than that, really?
“Volunteering is like dinner. You just figure out how to make it happen, no matter how busy you get,” she continued. “But I’m also very fortunate professionally. After all, who gets to participate in two brand-new industries during their career? Every day I’m surrounded by so much innovation and so many very cool people. I’ve been on aircraft carriers, race car wind tunnels, drone launches…you name it. I’m truly blessed.”