Researchers from MIT have developed a new kind of 3D printer that squirts out liquid metal to rapidly produce big objects like components for furniture. The system deposits molten aluminium through a path of tiny glass beads not unlike a mould. To demonstrate, the team created sturdy parts like chair legs.
“If we could make this machine something that people could actually use to melt down recycled aluminium and print parts, that would be a game-changer in metal manufacturing. Right now, it is not reliable enough to do that, but that’s the goal,” says Skylar Tibbits, associate professor in the Department of Architecture and co-director of the Self-Assembly Lab.
While the technique is apparently 10 times faster than other kinds of metal additive manufacturing processes, the resulting structures are quite rough around the edges. Still, the researchers believe it’s “suitable for some applications in architecture, construction, and industrial design, where components of larger structures often don’t require extremely fine details,” according to MIT News. “It could also be utilised effectively for rapid prototyping with recycled or scrap metal.”
The team chose aluminium because it is commonly used in construction and can be recycled cheaply and efficiently.
Bread loaf-sized pieces of aluminium are deposited into an electric furnace, “which is basically like a scaled-up toaster,” Karsan adds. Metal coils inside the furnace heat the metal to 700 degrees Celsius, slightly above aluminium’s 660 degree melting point.
The aluminium is held at a high temperature in a graphite crucible, and then molten material is gravity-fed through a ceramic nozzle into a print bed along a pre-set path. They found that the larger the amount of aluminium they could melt, the faster the printer can go.