Engineering news
Doctoral student Brandon Sweeney and his advisor Micah Green at Texas A&M University claimed their method could “transform the landscape of 3D printing”. The team said they used traditional welding concepts to improve printed parts, potentially making them more immediately useful.
Printed parts are often not strong enough, said Sweeney, who began working with 3D-printed materials while working at an army research laboratory. The engineering student claimed plastic parts made with additive manufacturing (AM) are fracture-prone, causing issues with durability and reliability.
“I was able to see the amazing potential of the technology, such as the way it sped up our manufacturing times and enabled our CAD designs to come to life in a matter of hours,” said Sweeney. “Unfortunately, we always knew those parts were not really strong enough to survive in a real-world application.”
Along with Dr Green and Mohammad Saed, Sweeney thought of using carbon nanotubes to “weld” the layers together. However, the team knew they could not put the parts in an oven because they would melt. Instead, they decided to use microwaves for a more focused technique.
“We realized that we needed to borrow from the concepts that are traditionally used for welding parts together where you'd use a point source of heat, like a torch or a TIG welder to join the interface of the parts together,” said Sweeney. “You're not melting the entire part, just putting the heat where you need it.”
The team used the carbon nanotube composite to control where the heat hit the parts and bonded layers together. A thin layer of the material was put on the 3D printer filament before printing. It then became embedded within the part during the printing process, making the parts stronger. The engineers incorporated the microwave welding process into the 3D printer itself, so printed parts are welded as they are made.
“This is interesting sounding research,” said Josh Dugdale, technical manager of the Manufacturing Technologies Association to Professional Engineering. The technique could bring other advantages, he said.
“Making sure that components that have been additively manufactured are strong enough and have the structural integrity to perform is really important. There is some fascinating development work taking place around the world looking at how you can strengthen and stiffen AM components by using them in tandem with other materials. If the parts can be made in this way then the benefits that could be gleaned in areas like weight reduction could be significant.”
The team’s work was published in Science Advances.