CAREER: Microstructure and Size Effects on Metal Plasticity at Limited Length Scale

University Of Vermont & State Agricultural College, Burlington VT

Investigators

Abstract

TECHNICAL: Meaningful results related to strength and plasticity in one-dimensional metallic nanowires can only be achieved if the influences of microstructure and sample size are fully understood. The two foci of these research activities are to (1) use parallel atomistic simulation to characterize the complex interactions between lattice dislocations and special grain boundaries in gold and nickel nanowires, and (2) measure the strength, ductility and strain-rate sensitivity of gold and nickel nanowires with controlled microstructures and grain size using applied electrochemical methods and atomic force microscopy. This would enable the PI to prove both theoretically and experimentally that special grain boundaries such as twin boundaries can dramatically improve these properties in nanowires. The intellectual merit lies in the presentation of a combined experimental/modeling research approach harnessing the power of both atomistic simulation and atomic force microscopy. This combination of methodologies will be very successful in bridging the gap between experiment and modeling in the mechanical characterization of individual nano-building block materials. Another potential outcome of such approach can be to rapidly help establish new standard methods and calibration procedures to test nanowires, as well-defined as nanoindentation technique for thin films, open up new research areas and lead to more findings. The research is also expected to show new ways to fabricate nanorods and nanowires with specific defects that make them stronger. NON-TECHNICAL: The educational component of this 5-year plan is strongly integrated to the multidisciplinary research program. The PI will make major educational and outreach contributions at the University of Vermont (UVM) to (1) spearhead the effort of revising the graduate engineering program with a focus on Multiscale Systems and Modeling; (2) structure international student exchanges with eight European engineering-specific programs at undergraduate level via the existing International Student Exchange Program (ISEP); and (3) develop a vigorous outreach program, via a novel scientific imaging which cross-cuts with the photographic arts, to improve the recruitment in engineering of students from rural high schools in Northern Vermont and the Abenaki Indian tribe in the Missisquoi Valley community. This CAREER award will also broadly advance the understanding in the field while promoting educational training of undergraduate and graduate students involved in the research project. In particular, this award is expected to enhance the education of students in the area of high performance and parallel computing, and high-resolution imaging. The graduate students will also have opportunities to broadly disseminate the results of the research at national conferences and meetings to enhance scientific understanding in the field. This CAREER award will stimulate the use of a multi-user facility, UVM's newly-established Vermont Advanced Computing Center, and involve the participation of scientists at a new US DOE's national research facility. The education program of this CAREER award will broadly revitalize the interest for materials science and engineering at UVM, help recruit engineering students from underrepresented groups, and improve the student's multicultural training.