Microstructure and homogeneity of nanocrystalline Co–Cu supersaturated solid solutions prepared by mechanical alloying

Abstract

Mechanical alloying (MA) has been performed in the CoxCu(100−x) (x = 10, 25, 50, 60, 75, and 90) system. High resolution electron microscopy (HREM) and field emission gun transmission electron microscopy (FEG TEM) were used to characterize the micro-structure and homogeneity of the nanocrystalline Co25Cu75 solid solution. After 20 h of MA, all the mixtures show an entirely face-centered cubic (fcc) phase. HREM shows that the ultrafine-grained (UFG) materials prepared by MA contain a high density of defects. Two kinds of typical defects in UFG Co25Cu75 are deformation twins and dislocations. The dislocations are mostly 60° type, and in many cases they dissociate into 30° and 90° partials. The grain boundaries are ordered in structure, curved, and slightly strained, which is similar to that observed in NC–Pd. Nanoscale energy dispersive x-ray spectroscopy (EDXS) shows that the Co concentration in both the interior of grains and the GB’s is close to the global composition, which proves that supersaturated solid solutions are indeed formed. In the meantime EDXS revealed that the mixing of Co and Cu in the solid solutions is homogeneous at nanometer scale. MA in the Co–Cu system is suggested to be a diffusion-controlled process, and stress-stimulated diffusion is proposed to be the reason for the formation of supersaturated solid solutions in this immiscible system.

This is a preview of subscription content, access via your institution.

References

  1. 1.

    K. Uenish, K. F. Kobayashi, S. Nasu, H. Hatano, K. N. Ishihara, and P. H. Shingu, Z. Metallkd. 82, 132 (1992).

  2. 2.

    A. R. Yavari, P. J. Desré, and T. Benameur, Phys. Rev. Lett. 68, 2235 (1992).

    CAS  Article  Google Scholar 

  3. 3.

    J. Eckert, J. C. Holzer, C. E. Krill III, and W. L. Jonson, J. Appl. Phys. 73, 2794 (1993).

    CAS  Article  Google Scholar 

  4. 4.

    J. Y. Huang, A. Q. He, and Y. K. Wu, Nanostruc. Mater. 4, 1 (1994).

    Article  Google Scholar 

  5. 5.

    E. Ma and M. Atzmon, Mater. Chem. Phys. 39, 249 (1995).

    CAS  Article  Google Scholar 

  6. 6.

    J. G. Cabañas-Moreno, V. M. Lopez, H. A. Calderon, and J. C. Rendon-Angels, Scripta Metall. 28, 645 (1993).

    Article  Google Scholar 

  7. 7.

    C. Gente, M. Oehring, and R. Bormann, Phys. Rev. B 48, 13244 (1993).

    CAS  Article  Google Scholar 

  8. 8.

    M. B. Baricco, N. Cowlam, L. Schiffini, P. P. Marci, R. Frattini, and S. Enzo, Philos. Mag. B 68, 957 (1993).

    CAS  Article  Google Scholar 

  9. 9.

    J. Y. Huang, Y. K. Wu, A. Q. He, and H. Q. He, Nanostruc. Mater. 4, 293 (1994).

    Article  Google Scholar 

  10. 10.

    P. P. Marci, S. Enzo, N. Cowlam, R. Frattini, G. Principi, and W. X. Hu, Philos. Mag. B 71, 249 (1995).

    Google Scholar 

  11. 11.

    F. Cardellini and G. Mazzone, Philos. Mag. A 67, 1289 (1993).

    CAS  Article  Google Scholar 

  12. 12.

    J. Y. Huang, Y. K. Wu, and H. Q. Ye, Appl. Phys. Lett. 66, 308 (1995).

    CAS  Article  Google Scholar 

  13. 13.

    J. Y. Huang, Y. K. Wu, and H. Q. Ye, Acta Mater. 44, 1201 (1996).

    CAS  Article  Google Scholar 

  14. 14.

    J. Y. Huang, Y. K. Wu, and H. Q. Ye, Acta Mater. 44, 1211 (1996); Mater. Sci. Eng. A 199, 165 (1995).

    CAS  Article  Google Scholar 

  15. 15.

    J. Y. Huang, Y. D. Yu, Y. K. Wu, and H. Q. Ye, Acta Mater. 45, 113 (1997).

    CAS  Article  Google Scholar 

  16. 16.

    G. Thomas, R. W. Siegel, and J. A. Eastman, Scripta Metall. Mater. 24, 201 (1990).

    CAS  Article  Google Scholar 

  17. 17.

    W. Wunderlich, Y. Ishida, and R. Maurer, Scripta Metall. Mater. 24, 403 (1990).

    CAS  Article  Google Scholar 

  18. 18.

    D. X. Li, D. H. Ping, H. Q. Ye, X. Y. Qin, and X. J. Wu, Mater. Lett. 18, 29 (1993).

    CAS  Article  Google Scholar 

  19. 19.

    C. Michaelsen, Philos. Mag. A 72, 813 (1995).

    CAS  Article  Google Scholar 

  20. 20.

    H. X. Sui, M. Zhu, M. Qi, G. B. Li, and D. Z. Yang, J. Appl. Phys. 71, 2945 (1992).

    CAS  Article  Google Scholar 

  21. 21.

    R. Z. Valiev, A. V. Korznikov, and R. R. Mulyukov, Mater. Sci. Eng. A 168, 141 (1993).

    Article  Google Scholar 

  22. 22.

    H. J. Fecht, E. Hellstern, Z. Fu, and W. L. Johnson, Metall. Trans. A 21, 2333 (1990).

    Article  Google Scholar 

  23. 23.

    D. A. Rigney, L. H. Chen, M. G. S. Naylor, and A. R. Rosenfield, Wear, 195 (1984).

  24. 24.

    S. K. Ganapathi and D. A. Rigney, Scripta Metall. Mater. 24, 165 (1990).

    Article  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to J. Y. Huang.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Huang, J.Y., Yu, Y.D., Wu, Y.K. et al. Microstructure and homogeneity of nanocrystalline Co–Cu supersaturated solid solutions prepared by mechanical alloying. Journal of Materials Research 12, 936–946 (1997). https://doi.org/10.1557/JMR.1997.0134

Download citation