Yu Research Group
About Us
The Yu Research Group explores processing science in advanced manufacturing, emphasizing the underlying process physics, mechanics, and materials science. 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.
With continual and sufficient energy supply in friction stirring, the printing process is under a far-from-equilibrium, 'driven' condition, which cannot be described using linear irreversible thermodynamics applicable to near-equilibrium scenarios. Through in situ or time-resolved characterization and theoretical innovation, we aim to develop an in-depth understanding of the unique kinetics of atomic transport and phase/microstructure evolution for such driven conditions. With the process and materials science fundamentals gained, 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.
Within the theme of additive friction stir deposition, our research portfolio includes process fundamentals (such as temperature and material flow), dynamic phase and microstructure evolution mechanisms, the design and manufacturing of heterostructured materials, and circular economy-related applications. Materials of interest include precipitate-strengthened alloys (e.g., aerospace grade 7xxx and 2xxx Aluminum), two-phase alloys (e.g., Ti-6Al-4V), pure metals (e.g., Cu), as well as functional materials, such as magnetic materials and shape memory alloys and composites. Kinetic phenomena of interest include continuous dynamic recrystallization, shear-induced mixing and segregation at the atomic scale, and shear-induced fracture and dispersion at the micro- and meso-scale. 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.