MSE Seminar: Selected Observations of Microstructural Development in Metallic Alloys
Friday, October 9, 2020
via Zoom only
Department of Materials Science and Engineering
University of Central Florida, Orlando
Title: Selected Observations of Microstructural Development in Metallic Alloys Additively Manufactured by Laser Powder Bed Fusion
Additive manufacturing (AM), commonly referred to as 3D printing, of metallic alloys is a disruptive technology that can produce net-shape components with nearly unlimited geometrical complexity and customization. This technology also brings an opportunity to design new and modified alloys based on robust understanding of phase equilibria and kinetics so that the dependent process variables are de-sensitized and thermo-kinetic environments associated with AM are utilized effectively. In this presentation, in-laboratory, hands-on, closed-loop experimental research capability for gas atomization and laser powder bed fusion (LPBF) for metallic alloy development will be first introduced. Selected observations of microstructural development from solidification, micro-segregation, cracking, homogenization, and precipitation will be presented for Al-, Mg-, Ni-, and Fe-base alloys, both commercially available and new/modified compositions. Properties for loadbearing, corrosion resistance, and biomedical applications will be explored for expansive application of AM technology. Practical use of knowledge in thermodynamics, phase diagrams and diffusion kinetics in designing and modifying the alloy composition for enhanced printability (or buildability) and properties will be highlighted. Pervasive throughout the presentation are the lessons and paths towards an understanding of the classical relation, structure-properties-processing (including AM) in materials science and engineering.
Dr. Yongho Sohn is a Pegasus Professor and Lockheed Martin Professor of Engineering in the Materials Science and Engineering Department at University of Central Florida. He received his B.S. with honors and M.S. from Worcester Polytechnic Institute, Worcester, MA in Mechanical and Materials engineering, respectively. He graduated in 1999 with Ph.D. in Materials Engineering from Purdue University and spent two years as a post-doctoral research scholar at the University of Connecticut. He joined University of Central Florida in 2001 as an assistant professor. His research and teaching interests includes metallic alloy powder processing and additive manufacturing, microstructural analysis and control, multicomponent intrinsic and interdiffusion in multiphase alloys, protective metallic/ceramic coatings for high temperature applications, light-weight metallic alloys and metal-matrix composites, and materials characterization. He is a Fellow of ASM International (FASM), recipient of NSF CAREER Award (2003), Outstanding Materials Engineer Award from Purdue University (2016), 2020 Engineer of the Year Award from Korean-American Scientists and Engineers Association, UCF’s 2017, 2012 and 2006 Research Incentive Awards, and UCF’s 2007 and 2013 Teaching Incentive Award. He is an Associate Editor for Journal of Phase Equilibria and Diffusion and a Board of Review member for Metallurgical and Materials Transactions. Details on his research and teaching activities can be found at http://mse.ucf.edu/sohn.