The Mechanism of Radiation-Induced Nanocluster Evolution in Oxide Dispersion Strengthened and Ferritic-Martensitic Alloys

Author

Matthew John Swenson, Boise State UniversityFollow

Publication Date

8-2017

Date of Final Oral Examination (Defense)

5-17-2017

Type of Culminating Activity

Dissertation

Degree Title

Doctor of Philosophy in Materials Science and Engineering

Department

Materials Science and Engineering

Supervisory Committee Chair

Janelle P. Wharry, Ph.D.

Supervisory Committee Co-Chair

Hui Xiong, Ph.D.

Supervisory Committee Member

Yaqiao Wu, Ph.D.

Supervisory Committee Member

James Cole, Ph.D.

Abstract

The objective of this study is to evaluate the mechanism of irradiation-induced nanoparticle evolution in a model Fe-9%Cr oxide dispersion strengthened steel and commercial ferritic-martensitic alloys HCM12A and HT9. Each alloy is irradiated with Fe²⁺ ions, protons, or neutrons to doses ranging from 1-100 displacements per atoms at 500°C. The morphology of nanoclusters are characterized using atom probe tomography. The evolution of clusters in each alloy are notably different with each irradiating particle, and the competing effects of ballistic dissolution and radiation-enhanced, diffusion-driven growth are attributed to the respective differences in cluster evolution. A phase evolution model, originally theorized by Nelson, Hudson, and Mazey, is used to simulate time-dependent nanocluster irradiation evolution in each alloy, with useful insights achieved to inform future alloy development. In all cases, a downward temperature shift is required to emulate low-dose-rate nanocluster evolution using higher-dose-rate irradiations.

DOI

https://doi.org/10.18122/B2GX21

Recommended Citation

Swenson, Matthew John, "The Mechanism of Radiation-Induced Nanocluster Evolution in Oxide Dispersion Strengthened and Ferritic-Martensitic Alloys" (2017). Boise State University Theses and Dissertations. 1319.
https://doi.org/10.18122/B2GX21