Accession Number : ADA303563

Title :   Experimental and Theoretical Investigations of Nanostructured Materials and Composites.

Descriptive Note : Final contract rept. Sep 91-Sep 95,

Corporate Author : MICHIGAN TECHNOLOGICAL UNIV HOUGHTON

Personal Author(s) : Aifantis, Elias C. ; Hackney, Stephen A. ; Milligan, Walter W.

PDF Url : ADA303563

Report Date : 01 DEC 1995

Pagination or Media Count : 54

Abstract : An interdisciplinary research program was conducted to understand the mechanisms of 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)

Descriptors :   *COMPOSITE MATERIALS, *DEFORMATION, *FRACTURE(MECHANICS), *POWDER METALS, SHEAR PROPERTIES, DISPLACEMENT, ELASTIC PROPERTIES, THIN FILMS, GRAIN SIZE, ROOM TEMPERATURE, STRAIN RATE, IRON, CRACK PROPAGATION, COPPER, PLASTIC PROPERTIES, GOLD, GRAIN BOUNDARIES, NANOTECHNOLOGY.

Subject Categories : Laminates and Composite Materials
      Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE