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Materials Science at Oregon State University

New Mechanistic Models to Predict Long-Term Evolution of Microstructure and Creep in Nickel Based Alloys

Date: Thursday, Nov 12th
Presenter: Dr. Agnieszka Truszkowska, OSU Materials Science

Abstract


Nickel based superalloys are used in fossil energy systems for their ability to provide high strength and corrosion resistance in chemically hostile environments at very high temperatures. Under these adverse operating conditions components’ lifespan is limited by the processes of creep, creep-fatigue, and microstructural evolution. The performance of nickel based alloys has been traditionally assessed by extrapolating from short timescale empirical data that either under- or overestimate materials microstructure evolution during its lifespan. The goal of our research team is to fill this gap by developing a totally new approach for prediction of microstructure evolution and creep in nickel superalloys. The central innovation of our approach is to model the alloys using the discrete element method (DEM). DEM is a well-established numerical method developed for modeling of granular materials like soil or rock. DEM is based ons simple particle interaction laws and can accurately predict material deformation, from the elastic regime to failure. Through this project we seek to reformulate DEM to model metal deformation while supplying the models with microstructure information developed through atomistic simulations via molecular dynamics and density functional theory. This talk is intended for a general audience — in it I will argue why a system for modeling dynamics of granular materials is well suited to model deformation of metals; I will present the progress that we have made to adapt DEM for this task; and I will describe the modeling that we are doing at other scales to inform our DEM simulations.

Bio
Agnieszka received her B.S. degree in Biotechnology from University of Belgrade in 2009. In 2014 she received her PhD in Chemical Engineering from Oregon State University with a minor in Mathematics. She is currently a postdoctoral fellow in Materials Science department at Oregon State University working under Dr. P. Alex Greaney, Dr. T. Matthew Evans and Dr. Jamie Kruzic. Agnieszka is interested in computational research in both the basic sciences and their engineering applications. Her PhD research was in computational fluid dynamics, in particular multiscale modeling of two-phase flows in microarchitectures. Her current group is developing a unique approach to model long-term deformation in metals and alloys.