Tennessee Tech explores innovations in metal casting technology
Fred Vondra, professor and chair of manufacturing and engineering technology at Tennessee
Tech.
Tennessee Tech University's Department of Manufacturing and Engineering Technology,
led by Chair and Professor Fred Vondra, is pioneering new approaches in metal casting
through the innovative use of technology.
This cutting-edge technique, known as lost-PLA, leverages the benefits of 3D printing
to revolutionize the traditional casting process, making it more efficient and cost-effective.
“Traditionally, metal casting has relied on the lost-foam process, where Styrofoam
is used to create a mold,” Vondra said.
Made from the same material as disposable coffee cups, this model is placed into a
sand mold. When molten metal is poured in, the Styrofoam dissolves, and a negative
space is left behind in the sand mold. In other words, as the molten metal fills the
sand mold, it displaces and takes the shape of the Styrofoam.
While effective, this method can be costly and time-consuming due to the initial creation
of the Styrofoam models.
"Lost-PLA casting offers significant advantages over the traditional lost-foam process,"
Vondra said. "With a 3D printer and a roll of PLA filament, which is widely available
and inexpensive, we can create precise models quickly and affordably. This eliminates
the need for costly Styrofoam molds and allows for easy variations in design."
PLA, or polylactic acid, is the most widely used filament in 3D printing. It has a
low cost, averaging $25 per two pounds, and a low melting point at 392 degrees Fahrenheit,
making it ideal for short-run metal casting projects.
"The ability to print PLA models on-demand means we can rapidly prototype and test
new casting products," Vondra explained. "It's a game-changer for our foundry, which
is currently adapting this relatively new phenomenon."
This innovative work is supported by a grant from the American Foundry Society.
"While lost-foam casting remains superior for high production runs, the initial cost
savings and flexibility of lost-PLA make it an excellent option for short-run and
prototype projects," Vondra said.
As an expert in metal casting, Vondra's career has been marked by his contributions
to setting up foundry processes.
"When I was a grad student at the University of Northern Iowa, I helped establish
their foundry. Now, as I approach retirement, I'm excited to set up a new foundry
in Tech's new ACME building," he said.
Earlier this summer, Vondra was among several American Foundry Society members who
traveled to Washington, D.C. to meet Sen. Marsha Blackburn, who was presented with
the organization's Manufacturing Champion Award. “Getting to meet with and talk to
her was a wonderful highlight,” he said.
Vondra and other professors in the Department of Manufacturing and Engineering Technology
provide students with hands-on experiences with cutting-edge processes to prepare
them for their future careers, and Tech is committed to advancing knowledge and innovation
through research and practical applications.
But while metal casting is central to manufacturing and engineering technology, Vondra
adds, it is also so much more.
“Metal casting is a skill, a craft and an art, all at the same time,” he said.
Vondra says he was reminded of this on his recent trip to the nation’s capital when
he viewed a moving piece of cast metal artwork at the Vietnam Veterans Memorial.
“It’s a sculpture of nurses receiving injured soldiers, and the expression on their
faces is of pure anguish. It’s profoundly impactful, and the artist’s talent in capturing
such emotion through metal casting was remarkable,” Vondra said.
Learn more about the Department of Manufacturing and Engineering Technology at https://www.tntech.edu/engineering/programs/met/index.php.
