January 23
@
4:00 PM
–
5:00 PM
The ME 903: Graduate Student Lecture Series features campus and visiting speakers who present on a variety of research topics in the field of mechanical engineering. Professor Tao Sun is a professor at Northwestern University.
Unveiling Metal 3D Printing with X-Ray Insight
Abstract: Metal additive manufacturing (AM) refers to a group of disruptive technologies that build metallic three-dimensional objects by adding feedstock materials layer-by-layer based on computer models. AM not only offers engineers the freedom to design geometrically complex parts but also presents material scientists with opportunities to synthesize and process novel materials with far-from-equilibrium phases and microstructures. While AM holds the promise of revolutionizing the manufacturing industry, building defect-free metal products with precise control of material microstructures and part performance remains challenging. Indeed, substantial fundamental issues exist in metal AM that must be addressed before the technology can reach its full potential.
My team has been applying operando high-speed X-ray imaging and diffraction techniques to investigate various metal AM processes. The superior penetration power of high-energy X-rays and the extremely high fluxes provided by the synchrotron facility enable the characterization of dynamic structural evolution in bulk metallic materials with unprecedented spatial and temporal resolutions. Many highly transient phenomena involved in metal AM processes and their complex interplays were investigated, particularly the mechanisms responsible for different types of structure defects and build anomalies.
In this presentation, I will first give a brief overview of the operando synchrotron experiments on various metal AM processes conducted by our team in recent years and highlight the key insights gained from these studies. Specifically, I will explain how measurements of structural dynamics enabled by cutting-edge X-ray techniques have advanced the development of numerical models, improved our understanding of defect formation, and facilitated the benchmarking of process sensors. Finally, I will discuss the unresolved scientific questions that could be explored in the next phase of synchrotron research, with a focus on the new opportunities offered by 4th-generation facilities, such as the recently upgraded APS.
Bio: Dr. Tao Sun is an Associate Professor of Mechanical Engineering at Northwestern University. He obtained his BS and MS in Materials Science and Engineering (MSE) from Tsinghua University and his PhD in MSE from Northwestern University. After PhD study, Dr. Sun conducted postdoctoral research at Argonne National Laboratory, where he was later promoted to Assistant Physicist and then Physicist. In 2019, he began his academic career as Associate Professor at the University of Virginia and later joined Northwestern in 2023. Dr. Sun’s research focuses on addressing fundamental challenges in advanced manufacturing using cutting-edge in situ and ex situ characterization techniques. His work emphasizes the in-depth understanding of energy-matter interactions, mass and heat flow, defect generation, and material structure evaluation involved in various additive manufacturing processes. Dr. Sun was the recipient of TMS Young Innovator Award in the Materials Science of Additive Manufacturing and was recently recognized as a Highly Cited Researcher by Clarivate.