New Center Aims to Push Boundaries of 3-D Printing
Rich Martukanitz holds two prototypes, one in each hand.
Both are models for the same jet engine bracket.
The holes where the brackets would attach to the engine line up exactly, and the overall dimensions of the parts are roughly equal, but that's where the similarities end.
The first design, a thick, heavy chunk, would make a good doorstop. The second is a hollowed-out set of spider arms, like a splayed but sturdy rack of ribs.
The prototypes are the before and after of an open competition sponsored by GE to redesign an actual engine bracket. The goal was to make it 30 percent lighter while retaining its original strength and mechanical properties. The difference illustrates some of the promise of additive manufacturing.
"You're reimagining components from the ground up," says Martukanitz, director of Penn State's Center for Innovative Materials Processing through Direct Digital Deposition, known as CIMP-3D. "You can manufacture components having features and characteristics that are near impossible to do with conventional processes. And you drastically cut manufacturing time, materials — and cost."
Additive manufacturing, sometimes known as 3-D printing, is exactly what it sounds like. Working from a computer-generated 3-D model, a "printer" puts down layer after layer of material, adding layers until the design is realized in a finished part.
Admittedly, there's a lot of hype attached to this new technology. But there's plenty of real-world promise, too. "It gives new freedom and flexibility to design engineers," Martukanitz says. "There's lots of excitement about this in the aerospace, medical, and oil and gas industries. Additive manufacturing is leading the resurgence of manufacturing in the U.S."
CIMP-3D, created in early 2012, aims to be a world-class resource for that resurgence. A university-wide collaboration, the center draws faculty from the College of Engineering, the College of Earth and Mineral Sciences, the Materials Research Institute and the Applied Research Laboratory. It has its roots in a quarter century of ARL expertise in laser-based deposition technologies — the core of the region's powder metal industry.
"We were doing this before additive manufacturing was in vogue," says Martukanitz, "so we have a leg up. When the field got hot, we were able to respond very quickly, because we had the infrastructure and the expertise already in place. CIMP-3D just brings everything together."
In early 2013, when President Obama announced the National Network for Manufacturing Innovation , a network of advanced manufacturing hubs, the center was designated as the metals node for the pilot National Additive Manufacturing Innovation Institute, now known as America Makes.
The 8,000-square-foot facility, located in Penn State's Innovation Park, is operated by ARL, with industrial partners Sciaky Inc., an electron-beam welding manufacturer based in Chicago, and Battelle Memorial Institute of Columbus, Ohio. It includes a design lab outfitted with a polymer prototyping machine, and a manufacturing demonstration facility that houses, in addition to an array of laser- electron beam- and ink jet-based deposition systems, an X-ray computed tomography machine that scans the interiors of finished parts, detecting defects and allowing for reverse engineering.
Researchers focus on advancing the technology, which means everything from improving design and manufacturing processes to basic materials science. Modeling is a major emphasis, and covers not just design but the ability to predict material properties and performance.
"It's really virtual experimentation before we build a part," Martukanitz says. "We have to address concerns that these processes produce the characteristics required for critical applications.
"We're not making doorstops, or trophies," he adds. "We want to make critical components: components for electrical and mechanical systems, orthopedic implants and jet engine parts."
For now, the focus is mostly on metal components, which are produced in both near-net and net shape. The first need finish machining, Martukanitz explains, while the latter are ready to go right out of the printer. Already, though, center researchers are looking at the possibilities for making parts from advanced materials, including ceramics and composites.
Gary Messing, co-director of the center, is head of the department of materials science and engineering and a ceramic scientist. "Additive manufacturing conditions can be radically different from those for conventional processes," he says. "There's a lot of materials science to be done to understand microstructures and properties. But I think ceramics have a role to play in this."
The center was recently named the manufacturing demonstration facility for additive manufacturing by the Department of Defense. Among other things, that means industrial partners can try out processes on the center's advanced systems, and also get expert advice. A recent change in the university's intellectual property policy, whereby intellectual property that results from industry-sponsored research no longer is mandated to be owned by the university, has helped attract interest in the facility from large corporations like Boeing, Northrup Grumman, Moog Corporation, Pratt & Whitney and Siemens, as well as small start-ups and individual entrepreneurs. Martukanitz reports more than 800 visitors to the center since its opening.
Last but not least, CIMP-3D boasts a robust education and training program for students and companies. Center co-director Tim Simpson, professor of mechanical and industrial engineering, leads this effort in partnership with Penn State's Digital Fabrication Network, known as DIGI-Net, and the Learning Factory, where teams of engineering students partner with industry to help solve real-world engineering problems for their senior design projects.
"What distinguishes us from other facilities of this type is both our breadth and depth of technologies," says Martukanitz. "We can cover a wide range of enabling technologies relevant to additive manufacturing, such as design, analysis, materials, processing, characterization and validation. We have faculty interests all over the board. We really are one-stop shopping. I don't think there's anyone else that can say that."