Dr. Alex Plotkowski
Materials Science & Technology Division
Oak Ridge National Laboratory

Process Modeling for Microstructure Control in Metal Additive Manufacturing

ABSTRACT: Metal additive manufacturing (AM) is a relatively new set of processes that have the potential to revolutionize the design and production of structural and functional components. In addition to the ability to produce complex geometric designs that cannot be fabricated with conventional processes, AM also offers an opportunity to locally control material microstructure and properties. However, the relationships between process, microstructure, and properties are complex. Computational modeling offers a pathway to optimizing process conditions to achieve a desired microstructural distribution, but the development of such modeling techniques faces its own challenges. The process dynamics are inherently multi-scale, with significant sources of uncertainty in both the knowledge of relevant physical parameters and in the set of model assumptions used at a given scale. The purpose of this presentation is to describe the range of relevant techniques for predicting relevant AM process dynamics for the purpose of controlling microstructure, as well as their limitations. Relevant examples and experimental case studies will be discussed in detail.

BIOGRAPHY: Alex Plotkowski received a B.S.E. in Mechanical Engineering and M.S.E. in Produce Development and Manufacturing from Grand Valley State University in 2012. He earned his Ph.D. in Materials Engineering from Purdue University 2016, where he studied the development computational fluid dynamics techniques for modeling alloy solidification during large-scale casting processes. Following his graduate studies, Alex worked as a Post-Doctoral Research Associate at the University of Tennessee-Knoxville, where he developed fast-acting heat transfer models for simulating additive manufacturing process dynamics, and studied non-equilibrium solidification phenomena in welding and AM. In 2017, he took a staff position in the Deposition Science & Technology group at ORNL. He is currently the acting group leader for Microstructural Evolution Modeling in the Materials Theory and Simulation section of the Materials Science & Technology Division at ORNL. His research involves the development of new materials for advanced manufacturing processes, and in the application of computational modeling approaches to understanding microstructure development during processing.