September 26
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1:00 PM
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2:00 PM
UW-Madison Department of Materials Science and Engineering welcomes this week’s seminar speaker, Associate Professor Hang Z. Yu. The seminar on “Shear-Driven Metallurgy for Additive and Sustainable Manufacturing” will be on Thursday, Sept. 26 in MS&E 265 from 1 p.m. to 2 p.m.
Abstract
Relying on melting and rapid solidification, mainstream fusion-based metal additive manufacturing processes are persistently challenged by a series of critical issues, including porosity, hot cracking, and high energy consumption. This presentation explores alternative approaches that bypass melting, specifically focusing on a shear-driven, non-equilibrium process known as additive friction stir deposition. This method offers high build rates, excellent scalability, and produces fully dense components with properties comparable to forged materials. With low cost and energy consumption, it supports agile manufacturing of a wide range of metals and alloys as well as metal matrix composites, opening new possibilities for large-scale near-net shaping, structural repair, remanufacturing, and the development of hybrid or functional materials. Moreover, thanks to its high tolerance of feedstock quality, additive friction stir deposition enables recycling and upcycling through simultaneous consolidation of scrap metals and dynamic evolution of microstructures and impurity phases. Beyond niche applications, this process offers a platform to quantitatively explore the unique kinetic phenomena under far-from-equilibrium conditions with sustained external forcing. By combining tracer-based experiments, in situ monitoring, AI-assisted process modeling, and time-resolved phase and microstructure analyses, we have unraveled new fundamental insights into atom transport and phase formation under such driven conditions, which cannot be described using linear irreversible thermodynamics applicable to near-equilibrium scenarios.
Bio
Dr. Hang Z. Yu is an Associate Professor in the Department of Materials Science and Engineering at Virginia Tech. He earned his B.S. in physics from Peking University in 2007 and his Ph.D. in materials science and engineering from MIT in 2013. He conducted postdoctoral research at MIT from 2013 to 2015 prior to joining the Virginia Tech faculty in 2016. Dr. Yu’s research focuses on the metallurgical fundamentals underlying advanced manufacturing, with an emphasis on process physics and kinetic phenomena. His research group specifically explores shear-driven, non-equilibrium processes like additive friction stir deposition, which can provide scalable, sustainable, and resilient alternatives to contemporary fusion-based additive technologies. Dr. Yu received the DARPA (Defense Advanced Research Projects Agency) Young Faculty Award in 2022 and currently serves as an editor for Materialia.