Two separate University of Pittsburgh research groups have received funding from America Makes to improve design development for three-dimensional printing.
Directed by faculty in Pitt’s Swanson School of Engineering, the two projects will receive more than $1.7 million.
Each group has a different approach to 3-D printing research. One group, led by Albert To, associate professor of mechanical engineering and material science, focuses on the design aspect of 3-D printing. The second group’s focus is on the process of additive manufacturing.
“What [are] the process parameters of the 3-D printing, what does that do to the material structure, and in turn, the final product that is generated,” said group leader Ravi Shankar, associate professor in the department of industrial engineering at Pitt. “So that’s really our approach in our research group, where we look at those underlying linkages between process, structure, and the outcomes.”
But what exactly is 3-D printing?
Shankar’s team deals with the direct metal laser sintering, which involves creating metallic components from computer aided design software. The printer lays down layers of powder, which is heated by a laser, traveling through the powder bed along pre-programmed paths, according to Shankar. The end result is a solid, three-dimensional object built from the bottom up.
Shankar says the majority of objects created using the printer come from high-performance alloys, such as titanium or stainless steel, which become usable parts in aerospace industries and biomedicine.
Before 3-D printing, groups would design a part on their computer, analyze it and then fabricate it in a machine shop, which could take weeks, Shankar said.
“The advantage of 3-D printing, of course, is that you take the design that you created on your computer, transfer it to the 3-D printer and in a matter of several hours, it autonomously generates the three-dimensional body that you designed on your computer,” he said.
Shankar’s group received $805,988 to create software tools which can help automate the design of “support structures” needed when the three-dimensional part is built. Currently, few rules exist for designing them. Shankar’s team is tackling how to create optimized supports.
DMLS printers retail at about $800,000. Consumer-level printers that deal with plastic materials run about $2,000.
Shankar says to imagine having a ledge-shaped region of the design, which is overhanging. If it’s only supported by a bed of powder underneath, it’s not going to be very stable. This is where the support structures come in.
“[They serve] both a mechanical role and a functional role to enable the direct metal laser sintering process to be used more reliably for creating metallic components, particularly with a focus on biomedical components,” Shankar said.
These little pillars also play a critical role in extracting heat and preventing distortions in the geometry and internal structure of the material being built.
Shankar says the technology is improving, along with the interest within the broader community. With that comes more motivation to come up with new innovations through additive manufacturing.
The effort is somewhere between infancy and maturity, he said.