Quantification of the microstructures of high purity nickel subjected to dynamic plastic deformation

Z.P. Luo, H.W. Zhang, Niels Hansen, K. Lu

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    A quantitative microstructural analysis is presented for pure polycrystalline nickel processed by means of dynamic plastic deformation at high strain rates (102–103 s−1) to strains from 0.3 to 2.9. This analysis covers a number of structural parameters, such as the spacing between and the misorientation angle across dislocation boundaries and high angle boundaries. These boundaries subdivide the structure on a finer and finer scale towards saturation at the highest strain. The structural evolution follows a hierarchical pattern from the formation of cells and cell blocks to a characteristic lamellar structure, which is similar to that observed in metals deformed at a low strain rate by conventional deformation processes. However, at a constant strain the increase in strain rate increases the dislocation density and reduces the distance between deformation-induced dislocation boundaries and high angle boundaries. Shear bands and twins have not been observed. In order to underpin the structural analysis, the mechanical properties as a function of strain have been determined by tensile and hardness tests. The flow stress is 850 MPa, showing that high strain rate deformation has potential as a method to produce strong nanostructured metals by imposing only a moderate strain.
    Original languageEnglish
    JournalActa Materialia
    Volume60
    Issue number3
    Pages (from-to)1322-1333
    ISSN1359-6454
    DOIs
    Publication statusPublished - 2012

    Keywords

    • Dynamic plastic deformation
    • Strain rate
    • Nickel
    • Convergent beam electron diffraction
    • Quantification

    Fingerprint Dive into the research topics of 'Quantification of the microstructures of high purity nickel subjected to dynamic plastic deformation'. Together they form a unique fingerprint.

    Cite this