{"678544":{"#nid":"678544","#data":{"type":"event","title":"PhD Proposal by Zifeng Wang","body":[{"value":"\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EZifeng Wang\u003C\/strong\u003E\u003Cbr\u003EAdvisor: Prof. Ting Zhu\u003C\/p\u003E\u003Cp\u003E\u003Cbr\u003E\u003Cem\u003Ewill propose a doctoral thesis entitled\u003C\/em\u003E,\u003C\/p\u003E\u003Cp\u003E\u003Cbr\u003E\u003Cstrong\u003EAtomic-Scale Investigation of Deformation Mechanisms in BCC Metals\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cbr\u003E\u003Cem\u003EOn\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cbr\u003ETuesday, December 3rd at 10:30 a.m.\u003Cbr\u003EMRDC 4115\u003C\/p\u003E\u003Cp\u003Eand\/or\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;Virtually via Zoom\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/gatech.zoom.us\/j\/9177065615?pwd=UE43WEZBZDZ6SmQ3eHhwRE1yUGF6dz09\u0022\u003Ehttps:\/\/gatech.zoom.us\/j\/9177065615?pwd=UE43WEZBZDZ6SmQ3eHhwRE1yUGF6dz09\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee\u003C\/strong\u003E\u003Cbr\u003EProf. Ting Zhu \u2013 George W. Woodruff School of Mechanical Engineering (advisor)\u003C\/p\u003E\u003Cp\u003EProf. Naresh N. Thadhani \u2013 School of Materials Science and Engineering\u003C\/p\u003E\u003Cp\u003EProf. David L. MacDowell \u2013 School of Materials Science and Engineering\u003C\/p\u003E\u003Cp\u003EProf. Joshua P. Kacher \u2013 School of Materials Science and Engineering\u003C\/p\u003E\u003Cp\u003EProf. Oliver N. Pierron \u2013 George W. Woodruff School of Mechanical Engineering\u003C\/p\u003E\u003Cp\u003E\u003Cbr\u003E\u003Cstrong\u003EAbstract\u003C\/strong\u003E\u003Cbr\u003EBody-centered cubic (BCC) crystals, known for their high strength at elevated temperatures, are crucial in extreme environments,. These properties make BCC metals, particularly refractory metals like molybdenum, tungsten, and niobium, valuable in aerospace and nuclear applications. However, they also exhibit brittleness at low temperatures due to limited dislocation mobility, a phenomenon driven by the ductile-to-brittle transition temperature (DBTT) and high Peierls stress, which inhibits dislocation motion.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EIn this proposal, in-situ high-resolution transmission electron microscopy (HRTEM) and molecular dynamics (MD) simulations are combined to study three key deformation mechanisms in BCC metals. First, we explore anomalous twinning in tungsten, revealing unexpected twin nucleation on the {112} twin plane with lower resolved shear stresses rather than the {112} anti-twin plane. Second, we investigate superplastic deformation in tungsten nanostructures, observing over 100% elongation at room temperature due to dislocation-grain boundary interactions. Finally, we examine fracture behavior in single-crystal molybdenum across temperatures up to 1100\u00b0C, identifying various crack propagation modes, involving dislocation activity, cleavage, and phase transitions from the initial BCC structure to the newly formed FCC and HCP structures. Understanding these mechanisms is crucial for guiding the design of materials that combine high strength and ductility, improving the mechanical performance of BCC metals across a range of temperatures, and enhancing their applications in industries such as aerospace and nuclear energy.\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003E\u003Cstrong\u003EAtomic-Scale Investigation of Deformation Mechanisms in BCC Metals\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Atomic-Scale Investigation of Deformation Mechanisms in BCC Metals"}],"uid":"27707","created_gmt":"2024-11-19 21:01:25","changed_gmt":"2024-11-19 21:01:59","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2024-12-03T10:30:00-05:00","event_time_end":"2024-12-03T12:00:00-05:00","event_time_end_last":"2024-12-03T12:00:00-05:00","gmt_time_start":"2024-12-03 15:30:00","gmt_time_end":"2024-12-03 17:00:00","gmt_time_end_last":"2024-12-03 17:00:00","rrule":null,"timezone":"America\/New_York"},"location":"MRDC 4115 and\/or   Virtually via Zoom ","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":""}}}