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Title: Comparative study of the mechanical properties of nanostructured thin films on stretchable substrates

Comparative studies of the mechanical behavior between copper, tungsten, and W/Cu nanocomposite based on copper dispersoïd thin films were performed under in-situ controlled tensile equi-biaxial loadings using both synchrotron X-ray diffraction and digital image correlation techniques. The films first deform elastically with the lattice strain equal to the true strain given by digital image correlation measurements. The Cu single thin film intrinsic elastic limit of 0.27% is determined below the apparent elastic limit of W and W/Cu nanocomposite thin films, 0.30% and 0.49%, respectively. This difference is found to be driven by the existence of as-deposited residual stresses. Above the elastic limit on the lattice strain-true strain curves, we discriminate two different behaviors presumably footprints of plasticity and fracture. The Cu thin film shows a large transition domain (0.60% true strain range) to a plateau with a smooth evolution of the curve which is associated to peak broadening. In contrast, W and W/Cu nanocomposite thin films show a less smooth and reduced transition domain (0.30% true strain range) to a plateau with no peak broadening. These observations indicate that copper thin film shows some ductility while tungsten/copper nanocomposites thin films are brittle. Fracture resistance of W/Cu nanocomposite thin film ismore » improved thanks to the high compressive residual stress and the elimination of the metastable β-W phase.« less
Authors:
 [1] ;  [2] ; ; ;  [3] ;  [4] ;  [5] ; ;  [6]
  1. Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf (Germany)
  2. (UPR 3346 CNRS), Université de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France)
  3. Institut P' (UPR 3346 CNRS), Université de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France)
  4. LSPM, (UPR 3407 CNRS), Université Paris 13, Institut Galilée, 99 avenue Jean-Baptiste Clément, 93430 Villetaneuse (France)
  5. Institut Jean Lamour (UMR 3079 CNRS), Université de Lorraine, Parc de Saurupt, CS 50840, 54011 NANCY Cedex (France)
  6. Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France)
Publication Date:
OSTI Identifier:
22314372
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COMPOSITE MATERIALS; COPPER; DIAGRAMS; DUCTILITY; FRACTURES; NANOSTRUCTURES; PLASTICITY; RESIDUAL STRESSES; STRAINS; SUBSTRATES; THIN FILMS; TUNGSTEN; X-RAY DIFFRACTION