Breakthrough in Metal Additive Manufacturing: Ring-Shaped Laser Eliminates Multiple Defects in PBF-LB Process

New Approach Tackles Common Defects in Additive Manufacturing
Researchers at the University of Wisconsin-Madison (UW-Madison) have developed an innovative solution to mitigate three common defects in metal parts produced using Laser Beam Powder Bed Fusion (PBF-LB) Additive Manufacturing. In a groundbreaking study published in the International Journal of Machine Tools and Manufacture, the team demonstrated that a ring-shaped laser beam can simultaneously reduce pores, rough surfaces, and large spatters in metal parts—issues that often compromise part quality and reliability.

Revolutionary Laser Technology and Enhanced Manufacturing Efficiency
Traditional research in metal additive manufacturing typically focuses on addressing one type of defect at a time. However, the new study, led by Associate Professor Lianyi Chen, presents a holistic approach that mitigates multiple defects simultaneously. The key innovation lies in the use of a ring-shaped laser beam instead of the conventional Gaussian-shaped beam, a change that significantly improves the overall quality of the manufactured parts.

“By understanding the mechanisms behind the defect formation, we were able to develop a solution that not only reduces defects but also speeds up the production process without compromising quality,” said Chen. This innovation holds particular promise for industries like aerospace, medical devices, and energy, where metal parts with complex geometries are increasingly required.

Addressing Common Defects in Metal Parts
Defects such as pores, voids, rough surfaces, and large spatters are common in metal parts produced through additive manufacturing. These issues can affect the mechanical properties, durability, and reliability of the parts, making them unsuitable for critical applications. The UW-Madison team’s research offers a significant step forward in ensuring that parts produced through PBF-LB are of higher quality and more reliable.

In-Situ Experiments and High-Speed Imaging for Deeper Insights
To better understand how the material behaves during the additive manufacturing process, the team used advanced synchrotron X-ray imaging at the Advanced Photon Source, a high-energy X-ray facility at Argonne National Laboratory. The combination of real-time X-ray imaging, numerical simulations, and theoretical analysis allowed the researchers to identify the mechanisms that reduce process instabilities, which in turn mitigate defects.

Furthermore, the research demonstrated that the ring-shaped laser beam can drill deeper into the material, enabling the production of thicker layers without causing instability—an essential factor in improving manufacturing productivity.

Collaborative Effort and Future Implications
This research was a collaborative effort between UW-Madison and Argonne National Laboratory, with key contributions from PhD student Jiandong Yuan and collaborators Qilin Guo, Luis Escano, and others. The study was funded by the National Science Foundation and the Wisconsin Alumni Research Foundation.

The breakthrough in using the ring-shaped laser beam not only improves the quality of metal parts but also enhances the productivity of the additive manufacturing process, a critical step towards more efficient production in industries that require high-performance metal components.