Unprecedented footage of a 3D printing process could lead to faster printers and stronger parts, according to the authors of a newly published study.
Engineers from Carnegie Mellon University and Argonne National Laboratory used one of the world’s most powerful x-rays to take high-speed video and photos of Laser Powder Bed Fusion at the Chicago-area lab.
Researchers said the LPBF technique can result in tiny cavities known as “vapor depressions” in the printed material, which could lead to cracks or other defects in finished parts. The study, published in the journal Science, noted that manufacturers often used a “trial and error” approach to combat the little-understood flaws.
Analysis of the high-speed images, however, showed that the defects can occur under nearly all conditions when a laser moving across a powder bed reaches enough power to boil metal.
The research represented the first time scientists were able to view the “keyhole phenomenon” — named for the shape of the larger cavities — and emphasized the importance of the laser’s focus during the LPBF process.
Engineers also said the research allowed them to be able to predict when the gaps would form. By taking the study’s findings into account, 3D printers could one day be able to print more durable parts at far higher speeds.
"Our research shows that you can predict the factors that lead to a keyhole — which means you can also isolate those factors for better results,” co-author and recent Carnegie Mellon graduate Ross Cunningham said in a statement.