Non-uniform Failure in Superplastic Ti-6Al-4V Alloy

초소성 Ti-6Al-4V 합금에서의 불균일 파손

  • Published : 2000.11.01

Abstract

A material model has been presented, at the continuum level, for the representation of superplastic deformation coupled with microstructural evolution. The model presented enables the effects of the spatial variation of distributions of grain size to be predicted at the process level. The model has been tested under conditions of both homogeneous and inhomogeneous stress and strain by carrying out detailed comparison of predicted distributions of grain size and their evolutions with experimentally obtained data. Experimental measurements have shown the extent of the spatial variation of the distribution of grain size that exists in the titanium alloy, Ti-6Al-4V. It is shown that whilst not large, the variations in grain size distributions are sufficient to lead to the development of inhomogeneous deformation in test pieces, which ultimately result in localisation of strain and failure.

Keywords

References

  1. Superplasticity in Aerospace-Aluminium, Proc, Int. Conf. Cranfield Design and manufaturing development of high strength aluminum aerospace parts by superplastic forming Koch, U.;Winkler, P-J.;R Pearce(ed.);L.Kelly(ed.)
  2. Superplasticity: 60 Years after Person, Proc. Conf. Titanium alloys for superplastic forming Wisbey, A.;Kearns, M.W.;N.Ridley(ed.)
  3. Superplasticity in Metals, Ceramics and Intermetallic, Proc. Symp. Superplasticity in use : A critical review of its status, trends and limits Winkler, P-J.;M.J.Mayo(ed.);M.Kobaysshi(ed.);J. Wadsworth(ed.)
  4. Met. Trans. v.10A Micro structural Influence on Superplasticity in Ti-6Al-4V Paton, N.E.lHamilton, C.H.
  5. Acta. Met. Mater. v.29 Grain size distribution effect in superplasticity Ghost, A.K.;Raj, R.
  6. Acta. Met. Mater. v.34 no.3 A Model for the Evolution of Grain Size Distribution during Superplastic Deformation Ghosh, A.K.;Raj, R.
  7. Acta. Met. Mater. v.41 no.11 Flow Stress Dependence on the Distribution of Grain Size in Polycrystals Kurzydlowski, K.J.;Bucki, J.J.
  8. Mater. Sci. Forum v.189 Grain size effect in high temperature creep and super plastic deformation of polycrystalline materials Shi, L.;Northwood, D.O.
  9. J. of strain Analysis v.31 Mechanisms-based constitutive equations for the super plastic behaviour of a titanium alloy Zhou, M.;Dunne, F.P.E.
  10. J. of Eng. Mater. Tech. v.118 A state variable constitute model for superplastic Ti-6Al-4V based on grain size Mosher, D.A.;Dawson, P.R.
  11. Superplasticity in crystalline solids Pilling, J.;Ridley, N.
  12. Met. Trans. v.10 Micro structural Influence on Superplasticity in Ti-64Al-4V Paton, N.E.;Hamilton, C.H.
  13. J. of Mech. Phys. Solid v.43 A frame work for constitutive relations and failure criteria for materials with distributed properties,with application to porous viscoplasticity Haghi, M.
  14. Proc. Instn. Mech. Engrs. v.211 Determination of superplastic constitutive equations and strain rate sensitivities for aerospace alloys Kim, T-W.;Dunne, F.P.E.
  15. Continuum Theory of Plasticity Khan, A.S.;Huang, S.