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Developing a predictive understanding of thermodynamics and kinetics of phase transformation and defect evolution during concurrent ion irradiation and transient heating


EMSL Project ID
50082

Abstract

As a part of PNNL Physical and computational sciences directorate seed LDRD project, we aim to develop a predictive understanding of the phase transformation pathway and defect evolution mechanisms that enables solid solution formation or compositional patterning in model single phase body centered cubic (BCC) alloys and BCC alloys with second phase precipitates under ion irradiation and/or photon irradiation and post-irradiation annealing. This project is directly relevant to designing radiation tolerant materials for future nuclear energy technologies. We will answer key questions related to how enthalpy of mixing of solute and matrix elements in BCC alloys dictate the formation of solid solution or compositional patterning under irradiation. We will also evaluate how the open packed BCC structure will modify the solute-vacancy and solute-self-interstitial interaction under irradiation. Another key aspect of study will be the balance between ballistic mixing and increased diffusion under irradiation that can either keep the starting microstructure of the alloy in a metastable state or drive it to stable equilibrium products. Overall the project will involve synthesis of thin films of metallic alloys, irradiation of them using EMSL Helium ion microscope and imaging them in STEM and APT in EMSL in addition to VASP DFT computational studies using EMSL Cascade super computer.

Project Details

Start Date
2017-10-24
End Date
2018-09-30
Status
Closed

Team

Principal Investigator

Arun Devaraj
Institution
Pacific Northwest National Laboratory

Team Members

Libor Kovarik
Institution
Pacific Northwest National Laboratory

Vaithiyalingam Shutthanandan
Institution
Environmental Molecular Sciences Laboratory

Related Publications

Devaraj A., Z. Xu, F. Abu-Farha, X. Sun, and L.G. Hector. 2018. "Nanoscale solute partitioning and carbide precipitation in a multiphase TRIP steel from Atom Probe Tomography." JOM. The Journal of the Minerals, Metals and Materials Society 70, no. 9:1752-1757. PNNL-SA-132326. doi:10.1007/s11837-018-2974-1
Elsaidi S.K., M.A. Sinnwell, A. Devaraj, T.C. Droubay, Z. Nie, V. Murugesan, and B.P. McGrail, et al. 2018. "Extraction of Rare Earth Elements using Magnetite@MOF Composites." Journal of Materials Chemistry A 6, no. 38:18438-18443. PNNL-SA-136516. doi:10.1039/c8ta04750b