Experimental and Theoretical Investigations of Nanostructured Materials andComposites

摘要

An interdisciplinary research program was conducted to understand the mechanismsof deformation and fracture in nanostructured materials. Experiments on thin film nanostructured metals found that deformation occurred by grain boundary sliding and grain rotation in nanostructured gold deformed at room temperature, with grain sizes less than 25 nm. Bulk iron-copper nanostructures with grain sizes in the 100 nm size range exhibited perfectly plastic behavior and intense shear banding as the primary deformation mechanism. A variety of modeling techniques were conducted to determine the effects of grain size on strength, and to determine the constitutive behavior of nanostructured metals. Models of gradient plasticity and elasticity were also developed for traditional materials and thin films. (MM).