101
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      High tensile ductility in a nanostructured metal.

        1 , , ,
      Nature
      Springer Science and Business Media LLC

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Nanocrystalline metals--with grain sizes of less than 100 nm--have strengths exceeding those of coarse-grained and even alloyed metals, and are thus expected to have many applications. For example, pure nanocrystalline Cu (refs 1-7) has a yield strength in excess of 400 MPa, which is six times higher than that of coarse-grained Cu. But nanocrystalline materials often exhibit low tensile ductility at room temperature, which limits their practical utility. The elongation to failure is typically less than a few per cent; the regime of uniform deformation is even smaller. Here we describe a thermomechanical treatment of Cu that results in a bimodal grain size distribution, with micrometre-sized grains embedded inside a matrix of nanocrystalline and ultrafine (<300 nm) grains. The matrix grains impart high strength, as expected from an extrapolation of the Hall-Petch relationship. Meanwhile, the inhomogeneous microstructure induces strain hardening mechanisms that stabilize the tensile deformation, leading to a high tensile ductility--65% elongation to failure, and 30% uniform elongation. We expect that these results will have implications in the development of tough nanostructured metals for forming operations and high-performance structural applications including microelectromechanical and biomedical systems.

          Related collections

          Author and article information

          Journal
          Nature
          Nature
          Springer Science and Business Media LLC
          0028-0836
          0028-0836
          Oct 31 2002
          : 419
          : 6910
          Affiliations
          [1 ] Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
          Article
          nature01133
          10.1038/nature01133
          12410306
          748d4ebf-90e1-476d-a724-aab75f38c3fa
          History

          Comments

          Comment on this article