Microstructural evolution of zirconium carbide (ZrCₓ) ceramics under irradiation conditions

<p>A comprehensive understanding of the microstructural evolution of Zirconium Carbide (ZrC₂) ceramics under irradiation conditions is required for their successful implementation in advanced Gen-IV gas-cooled nuclear reactors. The research presented in this dissertation focusses on elucidating the ion and electron irradiation response of ZrC₂ ceramics. In the first part of the research, the microstructural evolution was characterized for ZrC₂ ceramics irradiated with 10 MeV Au³⁺ ions up to doses of 30 displacement per atom (dpa) at 800 ºC. Coarsening of the defective microstructure, as a function of dose, was revealed by transmission electron microscopy analysis. The lack of change in the irradiated microstructure, at doses above 5 dpa, indicated that a balance between irradiation damage accumulation and dynamic annealing of defects was reached. It was also found that concurrent oxidation occurred during the ion irradiation. The effects of irradiation on the morphology and microstructure of the initial oxide formed on the surface of ZrC₂ were investigated. The concomitant reduction in size and surface coverage of the oxide nodules at high doses, indicated that oxide dissolution was the predominant mechanism under irradiation conditions.</p> <p>In the second part of the research, Zirconium Carbide (ZrC₂) was irradiated with 10 MeV Au³⁺ ions to a dose of 10 dpa and subsequently with 300 keV electrons in a transmission electron microscope (TEM). It was found that high-energy electron irradiation of pre-damaged ZrC₂ foils induce atomic mixing via radiation enhanced diffusion (RED), producing surface oxidation of the TEM foil.</p>

Name thesis:degree_name

Ph. D. in Nuclear Engineering

Grantor

Missouri University of Science and Technology

Year dc:date.available

2020

Author dc:creator

• Florez, Raul

• Electron Irradiation
• Ion Irradiation
• Raman
• TEM
• XRD
• Zirconium Carbide
• Materials Science and Engineering
• Nuclear Engineering

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/2821

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-3826