dc.contributor.advisor | Ju Li. | en_US |
dc.contributor.author | Yang, Yang | en_US |
dc.contributor.other | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering. | en_US |
dc.date.accessioned | 2019-07-15T20:37:12Z | |
dc.date.available | 2019-07-15T20:37:12Z | |
dc.date.copyright | 2019 | en_US |
dc.date.issued | 2019 | en_US |
dc.identifier.uri | https://hdl.handle.net/1721.1/121710 | |
dc.description | This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. | en_US |
dc.description | Thesis: Ph. D., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2019 | en_US |
dc.description | Cataloged from student-submitted PDF version of thesis. | en_US |
dc.description | Includes bibliographical references (pages 181-205). | en_US |
dc.description.abstract | In this thesis, computational and experimental techniques are developed to study the response of materials to radiation and corrosion environments at nanoscale, respectively. Firstly, controlled ion radiation has become a popular tool for the fabrication and modification of nanostructured materials as well as understanding materials degradation in radiation environment. Here we aim to overcome a major limitation in current 1D Monte Carlo simulation codes for ion radiation, i.e., the incapability to predict the primary radiation damage in nanoscale ion implantation experiments. A prototype code in MATLAB named "Mat-TRIM", and a more advanced code in C-language named "IM3D", are developed to accurately capture the key physics of ion-mater interaction in nano-structured materials in three-dimensions (3D). Using IM3D, we revealed the nano-beam and nano-target effect of ion radiation. | en_US |
dc.description.abstract | We then quantified the relative error of 1D approach in several classical examples, showing significant relative errors of more than 1000% when the beam/target- size is close to or smaller than the range of ions, indicating the necessity of full-3D simulations. We also observed a topological evolution of point defects' distributions in 3D when beam-size varies. Also, radiation is a powerful characterization tool. In particular, in-situ environmental transmission electron microscopy (E-TEM) technique, using electron radiation for imaging, enables direct observation of materials corrosion at nano/atomic resolution. Using this technique, we directly visualized the deformation of 2nm-thick surface oxide on aluminum nanotips under oxygen environment. We showed the native aluminum oxide can deform like liquid and self-heal its branches quickly at room temperature, rendering a continuous oxide layer without fracture/spallation during deformation. | en_US |
dc.description.abstract | We also developed a "mechanical-break-junction" method to overcome the difficulty of preparing fresh metal surface in a TEM for initial oxidation studies. A contrast experiment to aluminum oxidation is performed for zirconium alloy, a metal which is used as the cladding in water-cooled reactors. We in-situ observed the oxidation-induced crack/pore evolution at nanoscale. The crack/pores in oxide will form a percolated network, leading to the failure of oxide as a passivation layer. Our observations demonstrated that the plasticity of metal oxide is crucial for the oxidation resistance of metals. | en_US |
dc.description.statementofresponsibility | by Yang Yang. | en_US |
dc.format.extent | 205 pages | en_US |
dc.language.iso | eng | en_US |
dc.publisher | Massachusetts Institute of Technology | en_US |
dc.rights | MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. | en_US |
dc.rights.uri | http://dspace.mit.edu/handle/1721.1/7582 | en_US |
dc.subject | Nuclear Science and Engineering. | en_US |
dc.title | Nanoscopic materials response to radiation and corrosion environments | en_US |
dc.type | Thesis | en_US |
dc.description.degree | Ph. D. | en_US |
dc.contributor.department | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering | en_US |
dc.identifier.oclc | 1103918837 | en_US |
dc.description.collection | Ph.D. Massachusetts Institute of Technology, Department of Nuclear Science and Engineering | en_US |
dspace.imported | 2019-07-15T20:37:06Z | en_US |
mit.thesis.degree | Doctoral | en_US |
mit.thesis.department | NucEng | en_US |