Research Projects
Laser Powder Bed Fusion
Laser Powder Bed Fusion (LPBF) is a highly complex process involving numerous dynamic and transient phenomena. These include dynamic laser absorption and reflection, intense metal vaporization, intricate melt flow, high-velocity particle spattering, powder entrainment, keyhole oscillation and fluctuation, and rapid solidification with phase evolution. The interplay of these processes determines defect generation and microstructure development.
Our team investigates the ultrafast dynamics of LPBF using advanced experimental and computational tools. We aim to uncover the fundamental physics governing defect formation and build anomalies, as well as develop process monitoring techniques to detect defects during the printing process
Further reading
-
“Sub-millisecond keyhole pore detection in laser powder bed fusion using sound and light sensors and machine learning”, Materials Futures, 3 (2024) 045001
-
“Machine learning aided real-time detection of keyhole pore generation in laser powder bed fusion”, Science, 379, (2023) 89
-
“Critical instability at moving keyhole tip generates porosity in laser melting”, Science, 370, (2020) 1080
-
“Keyhole Threshold and Morphology in Laser Melting Revealed by Ultrahigh-Speed X-ray Imaging”, Science, 363, (2019) 849
-
“Bulk explosion induced metal spattering during laser processing”, Physical Review X, 9, (2019) 021052
-
“Real-time monitoring of laser powder bed fusion process using high-speed X-ray imaging and diffraction”, Scientific Reports, 7, (2017) 3602
Wire Laser Directed Energy Deposition
Wire laser directed energy deposition (DED) is an additive manufacturing technology that offers significant advantages for building large-scale metallic components, owing to its fast deposition rate, high feedstock efficiency, and low manufacturing costs. While wire-laser DED may appear to be a straightforward process, the structural dynamics are far more complex, particularly using a coaxial printhead with multiple laser sources.
Our team focuses on understanding and controlling microstructure evolution in the wire laser DED process. We are particularly interested in uncovering the non-classical solidification behaviors that arise under unique processing conditions. In addition, we are actively developing enabling approaches, based on feedstock engineering, for printing advanced metallic, composite, and multi-material systems using a single wire feeder.
Further reading:
-
“An operando synchrotron study on the effect of wire melting state on solidification microstructures of Inconel 718 in wire-laser directed energy deposition”, International Journal of Machine Tools and Manufacture, 194 (2024) 104089
-
“Tailoring material microstructure and property in wire-laser directed energy deposition through a wiggle deposition strategy”, Additive Manufacturing, 77, (2023) 103801
Binder Jetting
Binder jetting is one of the most versatile additive manufacturing techniques, capable of working with nearly all classes of materials. The binder jetting production process separates the printing and densification steps, avoiding non-equilibrium conditions that often complicate product qualification and certification. Therefore, it is particularly suitable for mass production of parts with complicated geometries in industrial settings.
Our team is interested in understanding and controlling the printing and sintering processes in binder jetting. In addition, we are exploring innovative applications of binder jetting for manufacturing high-performance batteries.
Further reading
-
“Ink-based Additive Manufacturing for Electrochemical Applications”, Heliyon, 10, (2024) e33023
-
“Real time observation of binder jetting printing process using high-speed X-ray imaging”, Scientific Reports, 9, (2019) 2499
Acknowledgement
We acknowledge supports to our research from the following funding agencies
© Copyright 2024 FAST-AM Lab
Contact
Prof. Tao Sun
Department of Mechanical Engineering
2145 Sheridan Rd, Evanston, IL, 60208
taosun@northwestern.edu
1-847-467-2676