Professor Xun Liu awarded NSF CAREER Award to study ultrasonically assisted wire arc additive manufacturing
The Department of Materials Science and Engineering congratulates Professor Xun Liu for being awarded a Faculty Early Career Development (CAREER) Award.
The National Science Foundation recognizes early-career faculty like Dr. Liu, who are leaders in their roles as a researcher and educator. Xun Liu, an assistant professor of welding engineering in the Department of Materials Science and Engineering, has received a five-year Faculty Early Career Development (CAREER) Award for her research on “Ultrasonically Assisted Wire Arc Additive Manufacturing of Metal Matrix Nanocomposites for High-strength, Lightweight Structures”.
Metal matrix nanocomposites (MMNC) are a promising class of lightweight materials where the well-dispersed nanoparticles within the bulk metal matrix provide superior mechanical properties. Wire arc additive manufacturing (WAAM) enables direct manufacture of MMNC structural parts at large scale with freeform geometries. However, achieving desirable mechanical properties are challenging due to agglomeration of nanoparticles in the repeated melting cycles, solidification defects, and the as-cast microstructure features.
Ohio State is one of the original institutions in the U.S. studying power ultrasound, which includes contributions from renowned researchers Professor Robert C. McMaster and Professor Karl Graff. Professor Liu continues to blaze the power ultrasonic trail using a novel research process developed by the early-career faculty member and her team. Their innovative ultrasonically assisted (UA) WAAM process applies superimposed ultrasonic vibration during WAAM. Ultrasound is generally referred to as sounds with frequency of above 20kHz. In contrast to high frequency ultrasound, which is more commonly known for medical imaging or NDE applications, power ultrasound is in the lower frequency end, typically at 20kHz or 40kHz, whereas the power output is in a much higher range of several kilowatts. The multiple, non-linear physical phenomena associated power ultrasound in liquid and solid phases provide several unique advantages in enhancing manufacturing processes. For the purposes of this project, benefits of UA on WAAM are to disperse nanoparticles, refine the microstructure and minimize defects. Fundamental mechanisms involved in these effects will ultimately be discovered.
The multidisciplinary nature of this project, covering the fields of mechanical design, materials, metallurgy, data processing, thermo-mechanical modeling, and others provides a number of real-world, problem-based training opportunities for students at different levels. Results of this research can be transformed into various outreach activities that increase manufacturing career awareness in young generations and under-represented minorities through collaborations with different programs, e.g. TEK-8, PREFACE and WiE.
I think this award will be a great opportunity to further advance the knowledge of power ultrasound in advanced manufacturing and carry on the legacy of this research in our renowned welding engineering program. I would like to express my sincere appreciation to my colleagues, Department Chair Dr. Michael Mills and many other collaborators in support of this proposal submission.
Professor Xun Lui
In addition to this award, Dr. Liu is the PI of two active NSF projects focusing on the fundamental principles and engineering applications of power ultrasound. One study is in collaboration with the University of Michigan and focuses on ultrasonic effects on material mechanical behavior to improve incremental sheet metal forming process. The other study focuses on an innovative ultrasonically assisted resistance spot welding process for joining lightweight and dissimilar materials for which Dr. Liu’s team holds a patent. More details can be found on Liu's website.
Liu joined the welding engineering faculty roster at Ohio State in January 2018. Her strong background in experimental and computational research contribute to the department's academic and research pursuits and those of the country's only ABET-accredited program. Xun is a role model for young women and underrepresented minorities who are considering the welding engineering discipline.
