Grain boundary responses to heterogeneous deformation in tantalum polycrystals

Thomas R. Bieler, Scott C. Sutton, Bret E. Dunlap, Zackery A. Keith, Philip Eisenlohr, Martin A. Crimp, Brad L. Boyce

    Research output: Contribution to journalArticle

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    Abstract

    The evolution of heterogeneous deformation in a tantalum polycrystal was examined during a three-point bending experiment using electron backscatter pattern mapping. Slip bands formed at strains as low as 1%, and they became more intense with strain. Heterogeneous deformation was evident as intra-granular orientation gradients as large as 30° were observed after a strain of about 8%. Nonmonotonic changes in the local average misorientation distribution were observed, implying that dislocation substructure developed in a complex manner. Slip bands were analyzed using plane traces computed from local orientation information. With the assumption of uniaxial stress, Schmid factors for favorable slip systems were identified for each grain and compared with observations, showing evidence for macroscopic activity on both {110} and {112} slip systems. Reconstructed boundary data were used to estimate the geometric potential for slip transfer at grain boundaries. The correlations indicated that when active slip systems were favorably oriented for slip transfer across the boundary, it was often observed in the form of continuous slip bands aligned across the boundary. In boundaries where geometrical alignment and Schmid factors were not favorable for slip transfer, there was a higher likelihood to form ledges (topographic discontinuities) along the grain boundaries. Dislocation pileups at grain boundaries were also correlated with a low potential for slip transfer.

    Original languageEnglish (US)
    Pages (from-to)121-128
    Number of pages8
    JournalJOM
    Volume66
    Issue number1
    DOIs
    StatePublished - Jan 2014

    Profile

    Grain boundaries
    Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing)
    Carbamyl Phosphate
    Polycrystals
    Tantalum
    Common Bile Duct Diseases
    Hereditary Corneal Dystrophies
    Antitubercular Agents
    Addison Disease
    Dislocations (crystals)
    Electrons
    Experiments

    ASJC Scopus subject areas

    • Engineering(all)
    • Materials Science(all)

    Cite this

    Grain boundary responses to heterogeneous deformation in tantalum polycrystals. / Bieler, Thomas R.; Sutton, Scott C.; Dunlap, Bret E.; Keith, Zackery A.; Eisenlohr, Philip; Crimp, Martin A.; Boyce, Brad L.

    In: JOM, Vol. 66, No. 1, 01.2014, p. 121-128.

    Research output: Contribution to journalArticle

    Bieler, Thomas R.; Sutton, Scott C.; Dunlap, Bret E.; Keith, Zackery A.; Eisenlohr, Philip; Crimp, Martin A.; Boyce, Brad L. / Grain boundary responses to heterogeneous deformation in tantalum polycrystals.

    In: JOM, Vol. 66, No. 1, 01.2014, p. 121-128.

    Research output: Contribution to journalArticle

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