Journal of Materials Science

, Volume 16, Issue 2, pp 465–476 | Cite as

Investigation into the effect of an increase in tungsten content on the behaviour during ageing of maraging type Fe-Ni-Co-W alloys

  • E. Sakr
  • C. Servant
  • P. Lacombe


In the present paper, the behaviour during ageing is compared in the temperature range 400 to 500° C of the three martensitic alloys Fe-18.5 wt % Ni-8.99 wt % Co-4.87 wt % W, Fe-17.5 wt % Ni-8 wt % Co-8 wt % W and Fe-17 wt % Ni-8 wt % Co-10 wt % W. The kinetics of precipitation were followed by hardness measurements and small-angle X-ray scattering and electron microscopy studies. The ageing effect can be observed in three successive stages. In the second stage,with which a marked increase of the hardness is associated, there is formation and growth of intermetallic precipitates of (Fe, Ni, Co)3W≡A3W. These precipitates are elongated ellipsoids, of several nanometres in length. The preferred direction of growth of these precipitates is 〈111〉 of the martensitic matrix and the orientation relationship with the martensitic matrix is\(\{ 011\} _M //(010)_{A_3 W} \) and\(\left\langle {1\bar 11} \right\rangle _M //[100]_{A_3 W} \), identical to that found for the Ni3Mo precipitate in the quaternary alloys of the same composition but with the W-content substituted for by Mo; but none of the three above-mentioned stages corresponds to the formation ofω-phase.


Polymer Precipitation Electron Microscopy Tungsten Microscopy Study 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    J. Bourgeot, P. Maitrepierre, J. Manenc andB. Thomas, Fifth International Symposium, University of California, Berkeley, California (1971).Google Scholar
  2. 2.
    C. Servant, Thèse de Doctorat ès-Sciences, Université Paris Sud, Orsay (1972).Google Scholar
  3. 3.
    A. F. Yedneral andM. D. Perkas,Fiz. Metal. Metalloved 33 (1972) 315.Google Scholar
  4. 4.
    C. Servant, G. Maeder andP. Lacombe,Met. Trans. 6A (1975) 981.Google Scholar
  5. 5.
    A. Agnel, F. Hedin, G. Maeder, C. Servant andP. Lacombe,Acta Met. 25 (1977) 1445.Google Scholar
  6. 6.
    K. Shimizu andH. Okamota,Trans. Japan Inst. Met. 12 (1971) 273.Google Scholar
  7. 7.
    W. R. Bandi, J. L. Intz andL. M. Melnick,J. Iron Steel Inst. 207 (1969) 348.Google Scholar
  8. 8.
    C. Servant, G. Maeder andP. Lacombe,Met. Trans. 10A (1979) 1607.Google Scholar
  9. 9.
    C. Servant, P. Lacombe andM. Griveau,J. Mater. Sci. 15 (1980) 859.Google Scholar
  10. 10.
    G. Maeder, Thèse de Doctorat ès-Sciences, Université de Paris-Sud, Orsay (1975).Google Scholar
  11. 11.
    A. Guinier andG. Fournet, “Small angle scattering of X-rays”, (Wiley, New York, 1955).Google Scholar
  12. 12.
    J. Burke, “La cinétique des changements de phase dans les métaux”, (Masson Edit, Paris, 1968).Google Scholar
  13. 13.
    P. L. Gruzin,Dokl. Akad. Nauk. 94 (1954) 81.Google Scholar

Copyright information

© Chapman and Hall Ltd 1981

Authors and Affiliations

  • E. Sakr
    • 1
  • C. Servant
    • 1
  • P. Lacombe
    • 1
  1. 1.Laboratoire de Métallurgie Physique, associé au CNRS 177Université de Paris-SudOrsayFrance

Personalised recommendations