EAGER: Probing Deformation Mechanism Transition of Metals at the Nanoscale

William Marsh Rice University, Houston TX

Investigators

Abstract

TECHNICAL SUMMARY: The research goal of this EAGER project is to probe one of the most important problems on the mechanical behavior of metals at the nanoscale, namely experimental verification of the existence of a mechanism of plasticity involving the transition from a dislocation interaction controlled regime to a surface dislocation nucleation dominated regime. The specific technical objectives are to integrate recently developed in situ micro-mechanical nanoindentation stages in both the SEM and TEM. These will be used for systematic high-resolution quantitative investigations of the deformation of high-quality single crystalline Au, Ag, Cu and Ni nanowires with well-controlled dimensions. In addition to geometrical size effects, the roles of strain rate and temperature will also be investigated. NON-TECHNICAL SUMMARY: The study of deformation mechanisms in metals has been of paramount importance in developing the field of metallurgy. With the recent emergence of nanotechnology and the advancement of experimental techniques, investigating the deformation mechanism of metals at the nanoscale has become both technologically relevant and scientifically important. The successful implementation of the proposed work will help elucidate the important transitions from dislocation-interaction-controlled-plasticity to surface-dislocation-nucleation-controlled plasticity in metals. The studies carried out at different loading rates and temperatures will provide valuable information on kinetic aspects of metal plasticity at the nanoscale. The educational goal of this EAGER proposal is to inspire students to pursue successful careers in science and engineering fields. This will be done by integrating the proposed research work with a number of educational and outreach efforts, including creating innovative lab modules for undergraduate students at Rice, mentoring under-representative undergraduate students and local high school teachers and students for summer research experiences.