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Journal of Materials Science

, Volume 40, Issue 5, pp 1201–1208 | Cite as

Formation of porosity in ferritic ODS alloys on high temperature exposure

  • M. Turker
Article

Abstract:

In order to investigate the formation, distribution, growth behavior and volume fraction of porosity at high temperatures in ferritic Oxide Dispersion Strengthened (ODS) superalloys MA 956, ODM 751 and PM 2000 were exposed at 1100 and 1200C in air and in 2% oxygen containing nitrogen atmospheres for up to 8760 h. All samples exhibited small amounts of porosity (% < 0.1) in the as-received condition. During the early stages of exposure (up to 10 h) pores were generally located close to the surface of the samples. Later they were found in the central region of the samples and the volume fraction of porosity and the mean pore size increased. After exposure for 240–1000 h, mainly depending on sample thickness, the size and volume fraction of porosity reached a maximum value and then decreased. SEM and EDS analysis results showed that some pores contained small amounts of Ti, Al and Y rich particles which were distributed over the internal surface of pores. It was noted that when the volume fraction of porosity and the size of pores began to decrease the pores had filled with the matrix material. A relation was established between the production environment of the materials and the growth behavior of the pores.

Keywords

Porosity Central Region Nitrogen Atmosphere Matrix Material Internal Surface 
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.

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References

  1. 1.
    M. TURKER, Corros. Sci. 4-1/1 (1999) 1.Google Scholar
  2. 2.
    M. TURKER, H. CAMA and T. A. HUGHES, Corros. Sci. 37 (1995) 413.Google Scholar
  3. 3.
    A. H. ROSENSTEIN, J. K. TIEN and W. D. NIX, Met. Trans. 17A (1986) 151.Google Scholar
  4. 4.
    M. TURKER and T. A. HUGHES, in Proceedings of the 2nd International Conference on Microscopy of Oxidation (Cambridge, March 1993) p. 301.Google Scholar
  5. 5.
    G. KORB, in Proceedings of Conference on New Materials by MA Techniques, edited by E. Artz and L. Schultz (Calw-Hirasu, 1989) p. 175.Google Scholar
  6. 6.
    J. H. WEBER and P. S. GILMAN, Scripta Metallurgia 18 (1984) 479.Google Scholar
  7. 7.
    J. J. STHEPENS and W. D. NIX, Met. Trans. 16A (1985) 1307.Google Scholar
  8. 8.
    P. HANCOCK, in Proceedings of Conference on Vacancies’76, Bristol, edited by R. E. Smallman and J. E. Harris (Bristol University Met. Soc., 1976) p. 215.Google Scholar
  9. 9.
    J. KOMENDA and P. J. HENDERSON, Scripta Materialia 37 (1997) 1821.Google Scholar
  10. 10.
    M. J. BENNETT, H. ROMARY and J. B. PRICE, in Proceedings of Conference on Heat Resistance Materials (Fortana, Wisconsin, September 1991) p. 95.Google Scholar
  11. 11.
    H. D. HENDRICH, in Proceedings of Conference on New Materials by MA Techniques, edited by E. Artz and L. Schultz (Calw-Hirasu, 1988) p. 217.Google Scholar
  12. 12.
    M. TURKER and T. A. HUGHES, Oxidation of Metals 44 (1995) 505.Google Scholar
  13. 13.
    J. RITHERDON and A. R. JONES, Mat. at High Tem 18 (2001) 177.Google Scholar
  14. 14.
    H. D. HENDRICK, in “High Temperature Materials for Power Engineering” Part 1 (1990) p. 789.Google Scholar
  15. 15.
    Y. L. CHEN and A. R. JONES, Met. Mater. Trans. A 32A (2001) 2077.Google Scholar
  16. 16.
    P. K. SUNG, D. R. POIRIER, S. D. FELICELLI, E. J. POIRIER and A. AHMED, J. Crystal Growth 226 (2001) 363.Google Scholar
  17. 17.
    Y. L. CHEN, A. R. JONES and U. MILLER, Met. Mater. Trans. A 32A (2002) 2713.Google Scholar
  18. 18.
    M. TURKER, in Ph.D Thesis, University of Leeds School of Materials, UK, 1993.Google Scholar
  19. 19.
    M. TURKER, “8th International Metallurgy and Materials Congress” (Istanbul, Turkey, 1995) p. 161.Google Scholar
  20. 20.
    F. STARR, Private Communication (British Gas London Research Station).Google Scholar

Copyright information

© Springer Science + Business Media, Inc. 2005

Authors and Affiliations

  1. 1.Gazi University, Technical Education FacultyBesevler-AnkaraTurkey

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