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Metallurgical and Materials Transactions A

, Volume 36, Issue 7, pp 1737–1743 | Cite as

Formation of a new phase after high-temperature annealing and air cooling of an Fe-Mn-Al alloy

  • Wei-Chun Cheng
Article

Abstract

The observation of a new phase precipitated in the bcc matrix of a Fe-Mn-Al alloy heated at 1573 K and air cooled to room temperature is reported. The composition of the alloy was Fe-24.1 wt pct Mn-7.6 wt pct Al-0.03 wt pct C. These precipitates had a morphology of Widmanstätten side plates distributed uniformly in bcc grains, and some precipitates resided along the bcc grain boundaries. From transmission electron microscopy (TEM) and X-ray analyses, the crystal structure of the new phase was identified as a simple cubic (SC) Bravais lattice and was related to an ordered fcc phase. The new phase is similar to the L12 crystal structure. The orientation relationships between the SC Widmanstätten side plate and the ferrite matrix are [011]SC//[111]bcc and \((1\bar 11)\) SC//\((10\bar 1)\) bcc, which correspond to the well-know Kurdjumov-Sachs (K-S) orientation relationship. The formation of SC annealing twins from the ferrite phase at the initial stage of the nucleation during air cooling was observed for the first time in the Fe-Mn-Al alloys. It is noted that both twin grains grow within the ferrite matrix and maintain both the K-S orientation relationship with the parent ferrite phase and the twinning orientation relationship between them.

Keywords

Ferrite Austenite Material Transaction Orientation Relationship Ferrite Matrix 
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.
    P.R.S. Jackson and G.R. Wallwork: Oxid. Met., 1984, vol. 21, pp. 135–70.CrossRefGoogle Scholar
  2. 2.
    J.G. Duh and C.J. Wang: J. Mater. Sci., 1990, vol. 25, pp. 2063–70.CrossRefGoogle Scholar
  3. 3.
    V.G. Rivlin: Int. Met. Rev., 1983, vol. 17, pp. 309–37.Google Scholar
  4. 4.
    X.J. Liu, S.M. Hao, L.Y. Xu, Y.F. Guo, and H. Chen: Metall. Mater. Trans. A, 1996, vol. 27A, pp. 2429–35.Google Scholar
  5. 5.
    W.C. Cheng, H.Y. Lin, and C.F. Liu: Mater. Sci. Eng. A, 2002, vol. 335, pp. 82–88.CrossRefGoogle Scholar
  6. 6.
    K.H. Hwang, C.M. Wan, and J.G. Byrne: Scripta Metall., 1990, vol. 24, pp. 979–84.CrossRefGoogle Scholar
  7. 7.
    S.K. Chen, K.H. Hwang, C.M. Wan, and J.G. Byrne: Scripta Metall., 1990, vol. 24, pp. 151–56.CrossRefGoogle Scholar
  8. 8.
    K.H. Hwang, W.S. Yang, T.B. Wu, C.M. Wan, and J.G. Byrne: Acta Metall., 1991, vol. 39 (5), pp. 825–31.CrossRefGoogle Scholar
  9. 9.
    W.S. Yang, K.H. Hwang, T.B. Wu, J.G. Byrne, and C.M. Wan: Scripta Metall., 1990, vol. 24, pp. 1221–24.CrossRefGoogle Scholar
  10. 10.
    C.H. Chao and N.J. Ho: Scripta Metall., 1992, vol. 26, pp. 1863–68.CrossRefGoogle Scholar
  11. 11.
    W.B. Lee, F.R. Chen, S.K. Chen, G.B. Olson, and C.M. Wan: Acta Metall., 1995, vol. 43, pp. 21–30.Google Scholar
  12. 12.
    H.Y. Chu, F.R. Chen, and T.B. Wu: Scripta Metall., 1995, vol. 33 (8), pp. 1269–75.CrossRefGoogle Scholar
  13. 13.
    K.H. Hwang, C.M. Wan, and J.G. Byrne: Mater. Sci. Eng. A, 1991, vol. 132, pp. 161–69.CrossRefGoogle Scholar
  14. 14.
    W.C. Cheng and H.Y. Lin: Mater. Sci. Eng. A, 2002, vol. 323, pp. 462–66.CrossRefGoogle Scholar
  15. 15.
    W.C. Cheng, C.F. Liu, and Y.F. Lai: Scripta Metall., 2003, vol. 48, pp. 295–300.CrossRefGoogle Scholar
  16. 16.
    W.C. Cheng and H.Y. Lin: Mater. Sci. Eng. A, 2003, vol. 341, p. 106.CrossRefGoogle Scholar
  17. 17.
    M.C. Li, H. Chang, P.W. Kao, and D. Gan: Mater. Chem. Phys., 1999, vol. 59, pp. 96–99.CrossRefGoogle Scholar

Copyright information

© ASM International & TMS-The Minerals, Metals and Materials Society 2005

Authors and Affiliations

  • Wei-Chun Cheng
    • 1
  1. 1.the Department of Mechanical EngineeringNational Taiwan University of Science and TechnologyTaipeiTaiwan R.O.C.

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