Dr. Boopathy Kombaiah
Senior Scientist and Group Lead
Reactor Structural Materials Group
Idaho National Laboratory

Abstract

Interfaces in materials play a crucial role in controlling degradation processes in extreme environments, including radiation damage, creep, corrosion, and embrittlement. Understanding defect dynamics near interfaces in materials enables accurate prediction of the lifetime of components and design of damage-resistant materials in the energy industry. My talk will highlight the importance of defect dynamics near interfaces in evaluating and mitigating material degradation mechanisms under extreme conditions.

Firstly, I will discuss our efforts to explore experimental evidence for diffusional creep mechanisms by examining vacancy dynamics around stressed grain boundaries. Despite being used by materials scientists for several decades, diffusional creep theories remain vigorously debated due to a lack of direct experimental evidence and poor predictions of observed creep rates in materials. To validate these mechanisms, we employed experimental and multiscale modeling approaches to examine the signatures of creep-induced elemental redistribution (CIER) in alloys under diffusional creep conditions.

In the second portion of my talk, I will focus on enhancing damage tolerance in high-entropy alloys by utilizing the high density of interfaces produced by nanoprecipitates. Our experiments and simulations indicate that the interfaces in these alloys enable effective recombination of radiation-produced vacancies and interstitials, an essential mechanism for radiation tolerance. This materials design strategy, which incorporates a high density of interfaces, can be applied to other engineering alloy systems to improve their radiation tolerance.

Biography

Dr. Boopathy Kombaiah is a senior scientist in the Nuclear Materials Performance division and the lead of Reactor Structural Materials group at the Idaho National Laboratory. He earned his Ph.D. from North Carolina State University under the guidance of Prof. KL. Murty. Following this, he furthered his research as a postdoctoral associate at Carnegie Mellon University and Oak Ridge National Lab. Dr. Kombaiah’s research is centered on understanding materials degradation under extreme stress, temperature, and radiation environments. He employs advanced mechanical and microstructural characterization techniques to uncover damage mechanisms in materials. He has published over 40 peer-reviewed journal articles and presented his work at several international conferences. He is a recipient of 2015 American Nuclear Society (ANS)- Mark Mills award, 2022 Department of Energy Office of Science Early Career award, and 2024 INL Early Career Exceptional Achievement award.

Thursday, February 27. 2025
4:10 pm seminar

zoom link upon request