A team of Penn State researchers used a new 3D-printing method to produce a complex metal build that was once only possible with welding: fusing two metals together into a single structure.
Using an advanced additive manufacturing process known as multi-material laser powder bed fusion - enabled by a newly acquired system in Penn State's Center for Innovative Materials Processing Through Direct Digital Deposition (CIMP-3D) - the researchers printed a complex structure out of a blend of low-carbon stainless steel and bronze, which consists of 90% copper and 10% tin. The researchers published their approach in npj Advanced Manufacturing.
"In a process called selective powder deposition, we can now melt multiple powdered metals in a single layer during the additive manufacturing process - and we were the first university in the U.S. to do so," said Jacklyn Griffis, a doctoral candidate in mechanical engineering and first author of the paper. "The fine powders are tens of microns in diameter, almost like flour. We can selectively deposit the powder with micron-level resolution, then melt it together with a laser."
Researchers used an Aerosint selective powder deposition system, which CIMP-3D acquired in August 2023, to print and test the metal part. The system was integrated into an existing 3D Systems ProX320 AM machine in the Systems for Hybrid-Additive Process Engineering (SHAPE) Lab at CIMP-3D. A one-centimeter-tall metal part includes thousands of layers of metal powder, Griffis said, and takes a few hours to print.
"We now have the processing technology to print these multi-material metal parts, as well as a way to monitor the melt pool and observe and address potential issues in real time," said corresponding author Guha Manogharan, associate professor of mechanical engineering, head of the SHAPE Lab and co-director of CIMP-3D. "To do this, we produce a digital 3D rendering of the part through CT scans, which we use to look for pores, cracks at the interface or micron-scale defects."
