Dr. Balasubramaniam Radhakrishnan
Computational Sciences and Engineering Division
Oak Ridge National Laboratory

Large Scale Phase Field Simulations of Microstructures during Additive Manufacturing: Challenges and Approaches

ABSTRACT: During additive manufacturing by powder bed fusion processes, the material undergoes steep excursions in temperature at rates high enough to cause significant deviation from equilibrium during solidification and subsequent solid-state phase transformations occurring during subsequent cooling and post-process heat treatment. Quantitative prediction of processing-microstructure-property relationships in AM processed components is an extremely challenging endeavor that requires the development of advanced computational approaches, numerical techniques ,and implementation in state-of-the-art high performance platforms. This talk will focus on the simulation of solidification microstructures and the effect of structural inhomogeneity on the subsequent solid-sate transformation using massively parallel phase field simulations. The computational challenges and the strategies for mitigating the challenges will be discussed.

BIOGRAPHY: Bala Radhakrishnan is a Distinguished Research Staff in the Computational Engineering and Energy Sciences group at the Oak Ridge National Laboratory. He obtained his B.Tech and M.S. degress in Metallurgy and Physical Metallurgy from the Indian Institute of Technology, Madras, India, in 1975 and 1977, respectively. He worked as a Scientist in the Materials Division of the National Aeronautical Laboratory in India from 1977 to 1986. He obtained his Ph.D. in Materials Science and Engineering from the University of Alabama at Birmingham in 1989. Following his training as an experimental metallurgist, he turned a computational materials scientist since joining ORNL in 1993. His main research interest is in understanding the processing-microstructure-property relationships in metallic materials using a combination of materials theory and computational modeling. He is currently focusing his research on high performance computing related to microstructure evolution during additive manufacturing of structural alloys. His current research is mainly supported by the Exascale Computing Project, ExaAM, and by the HPC for Manufacturing (HPC4Mfg) program.