Additive manufacturing, or 3D printing, offers the ability to fabricate customized, complex parts traditionally unobtainable for a variety of applications including: on-site, rapid fabrication of metallic bone implants with patient-specific designs, replacement and optimization of legacy components (e.g., in the Departments of Defense and Energy), and repair of existing aerospace components in remote locations (e.g. outer space). However, metallic AM introduces a melt pool with rapid thermal cycles that result in microstructures featured with anisotropy and porosity, thus deteriorating the mechanical properties of AM metallic builds. This presentation will discuss our research on how to manipulate and promote the microstructures and properties of AM fabricated metallic components, by a high-throughput framework integrating computational, experimental and data-driven approaches. I will report three potential routes: (1) to optimize the processing conditions and/or melting strategies (line or spot) to tailor the columnar to equiaxed transition (CET) of grain structures, (2) to select and design nanoparticle-based inoculations as grain refiners to enhance the heterogeneous grain nucleation, and (3) to roll the deposited layer to produce large plastic strains that induce recrystallization for grain refinement. The knowledge from the research will enable the adoption of AM technologies for structural components, which have a great potential to reduce the waste of materials, revolutionize U.S. manufacturing, and increase the design flexibility in engineering. The talk will conclude with a discussion about future research, collaboration, and teaching interests.
Dr. Lei Chen is currently an assistant professor at Mississippi State University. Dr. Chen received his BS and MS degrees from Huazhong University of Science & Technology, China in 2005 and 2007 respectively, and PhD degree from the National University of Singapore in 2012. Chen’s research interest is in the broad area of advanced manufacturing and materials design, with a focus on additive manufacturing of metals and piezoelectric composites. His research group is supported by NSF, ORAU, ARL, and ONR-SBIR. Chen has published over 60 authored and co-authored papers in top international journals including Nature, Nature Communications, Acta Materialia, ASME Journal of Manufacturing Science and Engineering, Additive Manufacturing, Nano letters, Journal of Power Sources, etc. Chen has received 1630 citations to date. He has received a number of awards from universities and organizations worldwide. Recent awards include the prestigious ASEE Southeastern Section New Researcher Award (2018), ORAU Ralph E. Powe Junior Faculty Enhancement Award (2017), Southeastern Conference Visiting Faculty Travel Award (2016), Y. Z. Hsu Scientific Paper Award (2015), Chinese Excellent Self-financed Student Abroad Award (2012), and President Graduate Fellowship Award at National University of Singapore (2009).
Monday, February 11 at 2:00pm
Materials Research Building (MRB), 114
2005 Levy Ave., Tallahassee, FL