CAREER: Fundamental Insights into Deformation of Lightweight Alloys from Discovery-Class Atomistic Simulations

University Of North Texas, Denton TX

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The research objective of this award is to understand deformation science in ultralight, single-crystal, hexagonal close-packed magnesium-lithium (Mg-Li) alloys by using the state-of-the-art atomistic simulation methods such as accelerated molecular dynamics (AMD). While the conventional molecular dynamics technique allows us to study deformation mechanisms in materials over nano-second timescales, AMD and other techniques allow study of large material systems containing important microstructural defects over experimentally relevant time scales. In many instances, the experimentally relevant timescales are at least six orders of magnitude larger than molecular dynamics time scales. In pursuit of this goal, we will explore some fundamental problems associated with defect interactions at the microstructural length scale and clarify fatigue processes in Mg-Li alloys using computational modeling. Deliverables include a catalog of fundamental components and basic mechanisms, modeling and analysis tools developed for this work, documentation of research results, student education, and research experiences for graduate and undergraduate students. Mg is about two-thirds as dense as aluminum. Replacing many automobile components with Mg alloys will reduce automobile weight, decrease the fuel consumption by about 30%, and cut down carbon-dioxide emission substantially. Li is the lightest metal known and it dissolves extensively in Mg. Thus, alloying Mg with Li can produce revolutionary, lightest weight structural alloys if we overcome fundamental issues such as instability of its room temperature mechanical properties. Our work will shed light in this important area. Other areas of impact include bridging the knowledge-divide between sighted and blind students through a digital library for the blind students, increasing the participation of high school, undergraduate, and graduate students in research, enhancing research and education experiences for student researchers through collaboration with our colleagues at national laboratories, conference presentations, and journal publications, and disseminating state-of-the-art research tools like AMD into the classroom curriculum rapidly.