Yu Research Group
About Us
The Yu Research Group explores the fundamental processing science in advanced manufacturing, emphasizing the underlying material kinetic phenomena along with processing physics and mechanics. The Yu Research Group is specifically recognized as a pioneer of solid-state metal additive manufacturing via additive friction stir deposition, which is characterized by rapid and extensive shear flow at elevated temperatures. Compared to mainstream fusion-based metal additive manufacturing, this process has demonstrated salient advantages in quality, properties, cost, energy consumption, and environmental impact. Our research strikes a balance between basic science and engineering:
Basic Science: The extensive shear-driven printing process is characterized by continual, sustained supply of energy and external forcing, therefore providing a good experimental platform to explore the unique kinetic phenomena under far-from-equilibrium, 'driven' conditions, which may not be properly described using linear irreversible thermodynamics applicable to near-equilibrium scenarios. We are interested in exploring the fundamentals of atomic transport (e.g., shear-induced segregation/mixing), microstructure evolution (e.g., continuous/discontinuous dynamic recrystallization; mechanical instability of inclusions), phase transformation, and interface bonding-- all under external force-driven conditions. Through in situ or time-resolved characterization and theoretical innovation (based on variables that can be measured in experiments to test the theory), we aim to gain an in-depth understanding of the phenomenological laws and governing mechanisms behind these intriguing processes.
Engineering: With the gained process and materials science fundamentals, we seek to establish quantitative process-structure-property linkages and advance material sustainability through niche applications via recycling, repair, and remanufacturing. Additionally, through collaboration, we are exploring advanced quality control schemes in solid-state additive manufacturing enabled by the integration of in situ monitoring, physics simulation, and Bayesian learning-based prediction. Material systems of interest include precipitate-strengthened alloys (e.g., aerospace grade 7xxx and 2xxx Aluminum), two-phase alloys (e.g., Ti-6Al-4V), immiscible binary systems, as well as functional materials, such as magnetic materials and shape memory alloys and composites. Applications of interest include structural repair, solid-state recycling (and upcycling), underwater printing, and robotic AM.
* We are proud to share that Professor Hang Yu is honored to be a recipient of the DARPA (Defense Advanced Research Projects Agency) Young Faculty Award. In the capacity of the lead PI, Professor Hang Yu has been fortunate to receive a DURIP (Defense University Research Instrumentation Program) Award of $800,000. This generous grant enabled the acquisition and installation of a state-of-the-art MELD L3 metal 3D printer, further enhancing our research capabilities. Our research group is also actively involved in contributing to the development of the world's largest metal 3D printer, which is currently under construction at Rock Island Arsenal, IL.
*In addition to these exciting developments, Professor Hang Yu has recently published a monograph titled 'Additive Friction Stir Deposition' with Elsevier in 2022. Furthermore, he is collaborating with Dr. Nihan Tuncer (Desktop Metal) and Dr. Zhili Feng (Oak Ridge National Laboratory) to edit a forthcoming book titled 'Solid-State Metal Additive Manufacturing: Physics, Processes, Mechanical Properties, and Applications,' which is currently in the press with Wiley-VCH.
*We are delighted to share some articles highlighting the achievements of our research group. One article is titled 'Research and Industry Partnership Helps Forge 21st Century Metallurgy'. Another article, published by the American Chemistry Society, is titled 'Metal 3D Printing Is Showing Its Mettle.' These articles provide insight into the impactful work our team is contributing to the field of metallurgy and 3D printing.
DIVERSITY, EQUITY, AND INCLUSION
The Yu Research Group at Virginia Tech advocates for the simultaneous advancement of technology and society as crucial elements for a more promising future. The group is dedicated to upholding its core principles of amplifying their influence by actively addressing diversity, equity, and inclusion (DEI) within the engineering domain:
With unwavering commitment, our team endeavors to cultivate a constructive professional and social atmosphere that embraces individuals of all backgrounds and ensures their acceptance and respect, irrespective of their race, ethnicity, gender, country of origin, religion, sexual orientation, or skin color, while addressing the world's most pressing engineering needs.
Featured News
Recently students in the Yu research group worked to assist Virginia Tech's unprecedented COVID-19 response by 3D printing face shield bands and assisting in design of N-95 replacement masks. As a whole Virginia Tech delivered more than 2000 face shields to surrounding hospitals and is poised to deliver critical components if the need arises.