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Acta Mechanica Solida Sinica

, Volume 23, Issue 3, pp 213–219 | Cite as

On Core Structure Properties and Peierls Stress of Dissociated Superdislocations in Aluminides: NiAl and FeAl

  • Xiaozhi Wu
  • Shaofeng Wang
  • Congbo Li
Article

Abstract

The study of dislocation properties in B2 structure intermetallics NiAl and FeAl is crucial to understand their mechanical behaviors. In this paper, the core structure and Peierls stress of collinear dissociated 〈111〉{110} edge superdislocations in NiAl and FeAl are investigated with the modified P-N dislocation equation. The generalized stacking fault energy curve along 〈111〉 direction in {110} slip plane contains two modification factors that can assure the antiphase energy and the unstable stacking fault energy to change independently. The results show that the core width of superpartials decreases with the increasing unstable stacking fault energy, and increases with the increasing antiphase boundary energy. The calculated Peierls stress of 〈111〉{110} edge superdislocations in NiAl and FeAl are 475 MPa and 3042 MPa, respectively. The values of Peierls stress in NiAl is in accordance in magnitude with the experimental and the molecular statics simulations results.

Key words

core structure Peierls stress NiAl FeAl 

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References

  1. [1]
    Lazar, P. and Podloucky, R., Ab initio study of the mechanical properties of NiAl microalloyed by X=Cr, Mo, Ti, Ga. Physical Review B, 2006, 73: 104114.CrossRefGoogle Scholar
  2. [2]
    Vailhé, C. and Farkas, D., Shear faults and dislocation core structure simulations in B2 FeAl. Acta Materialia, 1997, 45(11): 4463–4473.CrossRefGoogle Scholar
  3. [3]
    Medvedeva, N.I., Mryasov, O.N., Gornostyrev, Y.N., Novikov, D.L. and Freeman, A.J., First-principle total-energy calculations for planar shear and cleavage decohesion process in B2–ordered NiAl and FeAl. Physical Review B, 1996, 54: 13506–13514.CrossRefGoogle Scholar
  4. [4]
    Ferre, D., Cordier, P. and Carrez, P., Dislocation modeling in calcium silicate perovskite based on the Peierls-Nabarro model. American Mineralogist, 2009, 94: 135–142.CrossRefGoogle Scholar
  5. [5]
    Shen, Y. and Cheng, X., Dislocation movement over the Peierls barrier in the semi-discrete variational Peierls framework. Scripta Materialia, 2009, 61: 457–460.CrossRefGoogle Scholar
  6. [6]
    Christian, J.W. and Vitek, V., Dislocations and stacking faults. Reports on Progress in Physics, 1970, 33: 307–411.CrossRefGoogle Scholar
  7. [7]
    Miracle, D.B., The Physical and Mechanical Properties of NiAl. Acta Metallurgica et Materialia, 1993, 41(3): 649–684.CrossRefGoogle Scholar
  8. [8]
    Parthasarathy, T.A., Rao, S.I. and Dimiduk, D.M., Molecular statics simulations of core structures and motion of dislocations in NiAl. Philosophical Magazine A, 1993, 67(3): 643–662.CrossRefGoogle Scholar
  9. [9]
    Durinck, J., Legris, A. and Cordier, P., Influence of crystal chemistry on ideal plastic shear anisotropy in forsterite: First principle calculations. American Mineralogist, 2005, 90: 1072–1077.CrossRefGoogle Scholar
  10. [10]
    Li, T.S., Morris, J.W. and Chrzan, D.C., Ab initio study of the ideal shear strength and elastic deformation behaviors of B2 NiAl and FeAl. Physical Review B, 2006, 73: 024105.CrossRefGoogle Scholar
  11. [11]
    Wang, S.F., Lattice theory for structure of dislocations in a two-dimensional triangular crystal. Physical Review B, 2002, 65: 094111.CrossRefGoogle Scholar
  12. [12]
    Wang, S.F., A unified dislocation equation from lattice statics. Journal of Physics A: Mathematical and Theoretical, 2009, 42: 025208.MathSciNetCrossRefGoogle Scholar
  13. [13]
    Duesbery, M.S. and Richardson, G.Y., The dislocation core in crystalline materials. Solid State and Materials Science, 1991, 17(1): 1–46.Google Scholar
  14. [14]
    Wu, X.Z., Wang, S.F. and Zhang, H.L., Extended core structure of dissociated edge dislocations in fcc crystals with the consideration of discreteness, Acta Mechanica Solida Sinica, 2008, 21(5): 403–410.CrossRefGoogle Scholar
  15. [15]
    Lejcek, L., Dissociated dislocations in the Peierls-Nabarro model. Czechslovak Journal of Physics B, 1976, 26: 294–299.CrossRefGoogle Scholar
  16. [16]
    Wang, S.F., Wu, X.Z. and Wang, Y.F., Variational principle for the dislocation equation in lattice theory. Physics Scripta, 2007, 76: 593–596.CrossRefGoogle Scholar
  17. [17]
    Nabarro, F.R.N., Theoretical and experimental estimates of the Peierls stress. Philosophical Magazine A, 1997, 75(3): 703–711.CrossRefGoogle Scholar
  18. [18]
    Telling, R.H. and Heggie, M.I., Stacking fault and dislocation glide on the basal plane of graphite. Philosophical Magazine Letters, 2003, 83(7): 411–421.CrossRefGoogle Scholar
  19. [19]
    Wang, S.F., Dislocation energy and Peierls stress: a rigorous calculation from the lattice theory. Chinese Physics, 2006, 15(6): 1301–1309.CrossRefGoogle Scholar
  20. [20]
    Wu, X.Z. and Wang, S.F., Application of parametric derivation method to the calculation of Peierls energy and Peierls stress in lattice theory. Acta Mechenica Solida Sinica, 2007, 20(4): 363–368.CrossRefGoogle Scholar
  21. [21]
    Woodward, C., First-principle simulations of dislocation cores. Materials Science and Engineering A, 2005, 400–401: 59–67.CrossRefGoogle Scholar

Copyright information

© The Chinese Society of Theoretical and Applied Mechanics and Technology 2010

Authors and Affiliations

  1. 1.Institute for Structure and FunctionChongqing UniversityChongqingChina
  2. 2.State Key Laboratory of Mechanical TransmissionChongqing UniversityChongqingChina

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