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Microstructure changes in two phase β+ γ Co-Ni-Al ferromagnetic shape memory alloys in relation to Al/Co ratio

  • W. Maziarz
  • J. Dutkiewicz
  • R. Santamarta
  • E. Cesari
Article

Abstract.

The microstructure of Co35 + x-Ni40 - x-Al25 (x = 0, 2.5, 5.0) ferromagnetic shape memory alloys annealed at 1200 °C and water quenched has been investigated by optical (OM) and analytical transmission electron microscopy (TEM). The microstructure consists of elongated grains of martensite and γ phase. Annealing twins were found frequently in the γ phase. The volume fraction of γ phase has been determined to be about 40%. TEM observations show twinned L10 martensite with {111}-type twinning plane and tetragonality c/a = 0.85 in all investigated alloys. Determination of the composition of β phase, allows to calculate Al/Co and e/a ratio in the range 7.68–8.40 in correlation with its Ms temperatures between 66 and 167 °C, respectively. An increase in the Al/Co ratio together with a decrease of Ni content in β phase causes a decrease of the e/a ratio, which promotes a decrease of martensitic transformation temperatures.

Keywords

Martensite 40Ni 35Al European Physical Journal Special Topic Martensite Plate Annealing Twin 
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. R.C. O'Handley, J. Appl. Phys. 83, 3263 (1998) Google Scholar
  2. K. Oikawa, L. Wulff, T. Lijima, F. Gejima, T. Ohmori, A. Fujita, Appl. Phys. Lett. 79, 3290 (2001) Google Scholar
  3. J. Liu, H.X. Zheng, Y. Huang, M. Xia, J.G. Li, Scr. Mater. 53, 29 (2005) Google Scholar
  4. B. Bartova, D. Schryvers, Z. Yang, S. Ignacova, P. Sittner, Scr. Mater. 57, 37 (2007) Google Scholar
  5. J. Liu, H.X. Zheng, J.G. Li, Mater. Sci. Eng. A 438-440, 1061 (2006) Google Scholar
  6. H.Y. Wang, Z.H. Liu, Y.G. Wang, X.F. Duan, G.H. Wu, J. Alloys Comp. 400, 145 (2005) Google Scholar
  7. R.F. Hamilton, H. Sehitoglu, C. Efstathiou, H.J. Maie, Y. Chumlyakov, Acta Mater. 54, 599 (2006) Google Scholar
  8. J. Liu, J.G. Li, Mater. Sci. Eng. A 454-455, 423 (2007) Google Scholar
  9. A.I. Valiullin, S.V. Kositsin, I.I. Kositsina, N.V. Kataeva, V.A. Zavalishin, Mater. Sci. Eng. A 438-440, 1041 (2006) Google Scholar
  10. W. Maziarz, J. Alloys Comp. 448, 223 (2008) Google Scholar
  11. W. Maziarz, J. Dutkiewicz, R. Santamarta, E. Cesari, Acta Metall. Slov. 13, 160 (2007) Google Scholar
  12. Z.H. Liu, H.Y. Wang, S.Y. Yu, X.F. Dai, J.L. Chen, G.H. Wu, Y. Liu, Scr. Mater. 54, 1299 (2006) Google Scholar
  13. L.I. Vasiliev, A.N. Orlov, Uporiadochenie atomov i ego vlianie na svoistva splavov (Naukova Dumka, Kiev, 1968) Google Scholar
  14. V.A. Chernenko, Scr. Mater. 40, 523 (1999) Google Scholar
  15. K. Oikawa, T. Omori, Y. Sutou, R. Kainuma, K. Ishida, J. Phys. IV (France) 122 (2003) Google Scholar

Copyright information

© EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2008

Authors and Affiliations

  • W. Maziarz
    • 1
  • J. Dutkiewicz
    • 1
  • R. Santamarta
    • 2
  • E. Cesari
    • 2
  1. 1.Institute of Metallurgy and Materials Science of the Polish Academy of SciencesKrakowPoland
  2. 2.Departament de FísicaUniversitat de les Illes BalearsPalma de MallorcaSpain

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