{"554341":{"#nid":"554341","#data":{"type":"event","title":"PhD Proposal by Alex Bryant","body":[{"value":"\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003ETHE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EGEORGIA INSTITUTE OF TECHNOLOGY\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EUnder the provisions of the regulations for the degree\u003C\/strong\u003E\u003Cbr \/\u003E \u003Cbr \/\u003E \u003Cstrong\u003EDOCTOR OF PHILOSOPHY\u003C\/strong\u003E\u003Cbr \/\u003E \u003Cbr \/\u003E \u003Cstrong\u003Eon Tuesday, August 2, 2016\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003E12:00 PM\u003C\/strong\u003E\u003Cbr \/\u003E \u003Cstrong\u003Ein Love 295\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003E\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003Ewill be held the\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003E\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EDISSERTATION PROPOSAL DEFENSE\u003C\/strong\u003E\u003Cbr \/\u003E \u003Cbr \/\u003E \u003Cstrong\u003Efor\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EAlex Bryant\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003E\u0022Shock Compression Induced Phase Changes in Cerium-Based Metallic Glass\u0022\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EProf. Naresh N. Thadhani, Advisor, MSE\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EProf. Faisal Alamgir, MSE\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EProf. Arun M. Gokhale, MSE\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EProf. Josh Kacher, MSE\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003EDr. Christopher Wehrenberg,\u0026nbsp;LLNL\u003C\/strong\u003E\u003C\/p\u003E\u003Cp align=\u0022center\u0022\u003E\u003Cstrong\u003E\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbstract:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EThe proposed research is aimed at investigating pressure-induced phase changes in a Ce-based metallic glass (MG) through the use of laser-driven shock experiments and atomic resolution structural characterization. MGs exhibit very high strength, have intrinsically low density, and deform by shear banding. At high pressures and high strain rates, MGs can undergo phase changes that not only absorb energy, but also transform the structure into a higher density configuration with superior mechanical properties. However, the structural evolutions associated with shock compression induced phase transitions are not well understood. Understanding the atomic structure changes concomitant with these phase transitions is the motivation for this work.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EThe proposed research will involve performing laser-driven shock experiments at varying pressures on melt-spun Ce3Al MG and crystalline ribbons. The extreme pressure (~5 - 250 GPa) response of the MG will be investigated using the high energy Omega laser facility at the Laboratory for Laser Energetics. The lower pressure (~10 GPa) experiments will be performed using Nd:YAG laser driven shock compression and time-resolved velocity interferometry to determine the equation of state for the MG and its various phases. In addition, specimens will be recovered for post-impact structural analysis to gain information about the phases formed, transition states, and the mechanisms for the shock-induced phase changes. Structural analyses will be performed using synchrotron X-ray scattering, comparing macroscopic and atomic structure via X-ray diffraction (XRD), pair distribution function (PDF), and Extended X-ray Absorption Fine Structure (EXAFS). The ultimate goal will be to correlate the structural changes with shock compression conditions. Preliminary PDF results from recovery experiments at pressures \u0026gt; ~9.5 GPa indicate a shock-induced phase change resulting in a higher density amorphous structure. XRD measurements of recovered samples from ~120 and ~75 GPa experiments indicate shock-induced crystallization.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EThe overall\u0026nbsp;\u003Cem\u003Eobjective\u003C\/em\u003E of this research is to determine the phase changes and structural evolution occurring in the Ce3Al MG under shock compression and correlate those with the structural stability as a function of shock loading conditions. The \u003Cem\u003Esignificance\u003C\/em\u003E\u0026nbsp;of the proposed research is the advancement of the fundamental understanding of pressure-induced phase changes in metallic glasses.\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E \u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Shock Compression Induced Phase Changes in Cerium-Based Metallic Glass"}],"uid":"27707","created_gmt":"2016-07-20 13:48:08","changed_gmt":"2016-10-08 02:18:25","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2016-08-02T13:00:00-04:00","event_time_end":"2016-08-02T16:00:00-04:00","event_time_end_last":"2016-08-02T16:00:00-04:00","gmt_time_start":"2016-08-02 17:00:00","gmt_time_end":"2016-08-02 20:00:00","gmt_time_end_last":"2016-08-02 20:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"102851","name":"Phd proposal"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}