Researchers have discovered that applying a magnetic field during 3D printing can significantly reduce defects in metal parts.
This new method could lead to stronger and more reliable components for airplanes, race cars, and even medical implants.
Scientists from University College London (UCL) and the University of Greenwich used a powerful X-ray facility to observe how flaws form during 3D printing.
Their research, published in Science, shows that magnets can reduce tiny holes (pores) in metal parts by 80%, making them more durable.
In 3D printing, a computer-controlled laser melts layers of metal powder to build complex shapes. This process is used to create everything from aircraft parts to titanium bicycle frames and hip implants. However, when the laser melts the metal, it also creates vapor, forming small keyhole-shaped cavities. These cavities can collapse and leave behind tiny holes, weakening the final product.
To solve this problem, researchers applied a magnetic field while printing. The magnetic field helped stabilize the molten metal, changing the keyhole shape from an unstable J-shape to a stable I-shape. This prevented the cavities from collapsing and reduced the number of holes in the final part.
“When the laser heats the metal, it turns into liquid and produces vapor, which pushes the molten metal apart,” explains Dr. Xianqiang Fan, the study’s lead author. “This forms a J-shaped depression, which can break and create pores. Applying a magnetic field makes the process more stable, reducing these defects.”
To capture these changes in real time, the team used synchrotron X-ray imaging, a powerful technique that records images 100,000 times per second. They performed these experiments at the Advanced Photon Source (APS) in Chicago, which allowed them to see exactly how the molten metal behaves during 3D printing.
Professor Peter Lee from UCL explains, “For decades, we knew these tiny pores existed, but we didn’t fully understand how to prevent them. Now, thanks to high-speed X-ray imaging, we can see that thermoelectric forces—created by the magnetic field—help stabilize the molten metal and dramatically reduce defects.”
While this discovery is promising, there are still challenges to overcome before it can be widely used in manufacturing. Engineers will need to find ways to integrate magnetic fields into 3D printing systems on a large scale. However, the impact could be significant.
Professor Andrew Kao from the University of Greenwich adds, “This technique could revolutionize 3D printing, making it cheaper and faster to produce high-quality parts. Whether it’s artificial hip joints, battery packs for electric vehicles, or Formula 1 components, this new approach will improve manufacturing in many industries.”
With this breakthrough, the future of stronger, more reliable 3D-printed metal parts is closer than ever.
Source: KSR.
