Advertisement

Journal of Materials Science

, Volume 49, Issue 10, pp 3705–3715 | Cite as

Plastic material parameters and plastic anisotropy of tungsten single crystal: a spherical micro-indentation study

  • W. Z. Yao
  • C. E. KrillIII
  • B. Albinski
  • H. -C. Schneider
  • J. H. You
Article

Abstract

Enhancement of toughness is currently a critical engineering issue in tungsten metallurgy. The inherent toughness of tungsten single crystals is closely related to the capacity for local plastic slip. In this study we have investigated the plastic behavior of tungsten single crystals by means of micro-indentation experiments performed on specimens exposing (100), (110), and (111) surfaces. In parallel, FEM simulations were carried out with the Peirce–Asaro–Needleman crystal plasticity model considering both {110} 〈111〉 and {112} 〈111〉 slip systems. Plastic material parameters were identified by comparing the measured and predicted load–displacement curves as well as pile-up profiles. It is found that both measured and simulated plastic pile-up patterns on the indented surfaces exhibit significant anisotropy and orientation dependence, although the measured and simulated load–displacement curves manifest no such orientation dependence. The height and extension of pile-ups differ strongly as a function of surface orientation. The FEM simulations are able to reproduce the observed features of spherical indentation both qualitatively and quantitatively.

Keywords

Slip System Displacement Curve Critical Resolve Shear Stress Activate Slip System Plastic Slip 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

Part of this work was funded by EURATOM (FP7/2007-2011) under Grant Agreement 224752 and coordination action FEMaS. The author W.Z. Yao is also grateful to the Chinese Scholarship Council (CSC) for financial support.

References

  1. 1.
    Wurster S, Baluc N, Pippan R et al (2013) Recent progress in R&D on tungsten alloys for divertor structural and plasma facing materials. J Nucl Mater 442:181–189CrossRefGoogle Scholar
  2. 2.
    Gumbsch P, Riedle J, Hartmaier A, Fischmeister HF (1998) Controlling factors for the Brittle-to-Ductile transition in tungsten single crystals. Science 282:1293–1295CrossRefGoogle Scholar
  3. 3.
    Wronski A, Fourdeux A (1964) Slip-induced cleavage in polycrystalline tungsten. J Less-Common Metals 6:413–429CrossRefGoogle Scholar
  4. 4.
    Beardmore P, Hull D (1965) Deformation and fracture of tungsten single crystals. J Less-Common Metals 9:168–180CrossRefGoogle Scholar
  5. 5.
    Argon AS, Maloof SR (1966) Fracture of tungsten single crystals at low temperatures. Acta Metal 14:1463–1468CrossRefGoogle Scholar
  6. 6.
    Brunner D, Glebovsky V (2000) Analysis of flow-stress measurements of high-purity tungsten single crystals. Mater Lett 44:144–152CrossRefGoogle Scholar
  7. 7.
    Kaun L, Luft A, Richter J, Schulze D (1968) Slip line pattern and active slip systems of tungsten and molybdenum single crystals weakly deformed in tension at room temperature. Phys Stat Sol 26:485–499CrossRefGoogle Scholar
  8. 8.
    Asaro RJ, Needleman A (1984) Flow localization in strain hardening crystalline solids. Scr Metal 18:429–435CrossRefGoogle Scholar
  9. 9.
    Hutchinson JW (1976) Bounds and self-consistent estimates for creep of polycrystalline materials. Proc R Soc Lond A 348:101–127CrossRefGoogle Scholar
  10. 10.
    Peirce D, Asaro RJ, Needleman A (1982) An analysis of nonuniform and localized deformation in ductile single crystals. Acta Metal 30:1087–1119CrossRefGoogle Scholar
  11. 11.
    Hsiung LL (2010) On the mechanism of anomalous slip in bcc metals. Mater Sci Eng A 528:329–337CrossRefGoogle Scholar
  12. 12.
    Huang Y (1991) A user-material subroutine incorporating single crystal plasticity in the ABAQUS finite element program. Harvard University, CambridgeGoogle Scholar
  13. 13.
    Featherston FH, Neighbours JR (1963) Elastic constants of tantalum, tungsten, and molybdenum. Phys Rev 130:1324–1333CrossRefGoogle Scholar
  14. 14.
    Wright SJ (1930) The elasticity of pintsch crystals of tungsten. Proc R Soc Lond A 126:613–629CrossRefGoogle Scholar
  15. 15.
    Zambaldi C, Raabe D (2010) Plastic anisotropy of c-TiAl revealed by axisymmetric indentation. Acta Mater 58:3516–3530CrossRefGoogle Scholar
  16. 16.
    Yao WZ (2012) Crystal plasticity study of single crystal tungsten by indentation tests. PhD Thesis, Ulm University, UlmGoogle Scholar
  17. 17.
    Tabor D (1951) The hardness of metals. Oxford University Press, OxfordGoogle Scholar
  18. 18.
    Kothari M (1997) Polycrystalline elasto-viscoplasticity: application to BCC metals. PhD Thesis, MIT, CambridgeGoogle Scholar
  19. 19.
    Garfinkle M (1965) Room-temperature tensile behavior of 〈100〉 oriented tungsten single crystals with rhenium in dilute solid solution, Fourth Symposium on Refractory Metals NASA, IndianaGoogle Scholar
  20. 20.
    Lassner E, Schubert W-D (1999) Tungsten: properties, chemistry, technology of the element, alloys, and chemical compounds. Springer, BerlinCrossRefGoogle Scholar
  21. 21.
    Chiem CY, Lee WS (1994) The influence of dynamic shear loading on plastic deformation and microstructure of tungsten single crystals. Mater Sci Eng A 187:43–50CrossRefGoogle Scholar
  22. 22.
    Smith R, Christopher D, Kenny SD, Richter A, Wolf B (2003) Defect generation and pileup of atoms during nanoindentation of Fe single crystals. Phys Rev B 67:245405CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • W. Z. Yao
    • 1
  • C. E. KrillIII
    • 2
  • B. Albinski
    • 3
  • H. -C. Schneider
    • 3
  • J. H. You
    • 1
  1. 1.Max-Planck-Institut für Plasmaphysik, EURATOM AssociationGarchingGermany
  2. 2.Ulm University, Institute of Micro- and NanomaterialsUlmGermany
  3. 3.Karlsruher Institut für TechnologieInstitute for Applied MaterialsEggenstein-LeopoldshafenGermany

Personalised recommendations