Stability of Nanometer-Thick Layers in Hard Coatings


This article reviews two topics related to the stability of hard coatings composed of nanometer-thick layers: epitaxial stabilization and high-temperature stability. Early work on nanolayered hard coatings demonstrated large hardness increases as compared with monolithic coatings, but it was subsequently found that the layers interdiffused at elevated temperatures. More recently, it has been shown that nanolayers exhibit good stability at elevated temperatures if the layer materials are thermodynamically stable with respect to each other and are able to form low-energy coherent interfaces. This article discusses metal/nitride, nitride/nitride, and nitride/boride nanolayers that exhibit good high-temperature stability and hardness values that are maintained (or even increase) after high-temperature annealing. Epitaxial stabilization of nonequilibrium structures in thin layers is a well-known phenomenon that has been applied to hard nitride materials. In particular, AlN, which crystallizes in the hexagonal wurtzite structure in bulk form, was stabilized in the rock-salt cubic structure in nitride/nitride nanolayers (e.g., AlN/TiN). These results and the current understanding of epitaxial stabilization in hard nanolayers are discussed.

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  1. 1.

    S.A. Barnett, in Physics of Thin Films, edited by M. Francombe and J.A. Vossen (Academic Press, New York, 1993) p. 1.

  2. 2.

    S.A. Barnett and M. Shinn, Annu. Rev. Mater. Sci. 24 (1994) p. 481.

    CAS  Article  Google Scholar 

  3. 3.

    R.D. Bollier, “An Overview of the Market for Wear-Resistant Coatings Today and into the Next Century,” presented at the Wear and Superhard Coatings Conf., Tampa, Fla., 1998.

    Google Scholar 

  4. 4.

    P. Yashar, PhD thesis, Northwestern University, 1998.

    Google Scholar 

  5. 5.

    P.B. Mirkarimi, M. Shinn, and S.A. Barnett, J. Vac. Sci. Technol., A 10 (1992) p. 681.

    Article  Google Scholar 

  6. 6.

    A. Inspektor, F. Battaglia, E. Oles, E. Bauer, A. Gates, and U. Schleinkofer, “Advances and Technology Issues in Superhard Coatings for Cutting Tools,” presented at the Wear and Superhard Coatings Conf., Tampa, Fla., 1998.

    Google Scholar 

  7. 7.

    C. Engström, L. Hultman, A. Madan, S.A. Barnett, M. Nastasi, and C. Lavoie, “Mechanical and Thermal Stability of TiN/NbN Superlattice Thin Films” (unpublished manuscript).

  8. 8.

    K. Martin, PhD thesis, Northwestern University, 2001.

    Google Scholar 

  9. 9.

    K. Martin, A. Madan, I.W. Kim, and S.A. Barnett, “Effect of Annealing on the Mechanical Properties and Microstructure of ZrN/ZrB2 Films” (unpublished manuscript).

  10. 10.

    A. Madan, Y.-Y. Wang, S.A. Barnett, C. Engström, H. Ljungcrantz, L. Hultman, and M. Grimsditch, J. Appl. Phys. 84 (2) (1998) p. 776.

    CAS  Article  Google Scholar 

  11. 11.

    C. Engström, A. Madan, J. Birch, M. Nastasi, L. Hultman, and S.A. Barnett, J. Mater. Res. 15 (2000) p. 554.

    Article  Google Scholar 

  12. 12.

    A. Madan, S.A. Barnett, A. Misra, H. Kung, and M. Nastasi, J. Vac. Sci. Technol., A 19 (3) (2001) p. 952.

    CAS  Article  Google Scholar 

  13. 13.

    A. Madan, J. Ji, and S.A. Barnett, “High-Temperature Stability of Polycrystalline W/ZrN Nanolayered Thin Films” (unpublished manuscript).

  14. 14.

    A. Madan, I.W. Kim, S.C. Cheng, P. Yashar, V.P. Dravid, and S.A. Barnett, Phys. Rev. Lett. 78 (9) (1997) p. 1743.

    CAS  Article  Google Scholar 

  15. 15.

    I.W. Kim, Q. Li, L.D. Marks, and S.A. Barnett, Appl. Phys. Lett. 78 (2001) p. 892

    CAS  Article  Google Scholar 

  16. 15a.

    Q. Li, I.W. Kim, S.A. Barnett, and L.D. Marks, J. Mater. Res. 17 (2002) p. 1224.

    CAS  Article  Google Scholar 

  17. 16.

    A. Madan, PhD thesis, Northwestern University, 1997.

    Google Scholar 

  18. 17.

    I.W. Kim, A. Madan, M.W. Guruz, V.P. Dravid, and S.A. Barnett, J. Vac. Sci. Technol., A 19 (2001) p. 2069.

    CAS  Article  Google Scholar 

  19. 18.

    M. Setoyama, A. Nakayama, M. Tanaka, N. Kitagawa, and T. Nomura, Surf. Coat. Technol. 86–87 (1996) p. 225.

    Article  Google Scholar 

  20. 19.

    I.W. Kim, Q. Li, L.D. Marks, M.M. Guruz, V.P. Dravid, S.A. Barnett, A. Misra, H. Kung, and M.A. Nastasi, “Structure and Mechanical Properties of Epitaxial AlN/TiN Superlattices” (unpublished manuscript).

  21. 20.

    A. Madan, X. Chu, and S.A. Barnett, Appl. Phys. Lett. 68 (16) (1996) p. 2198.

    CAS  Article  Google Scholar 

  22. 21.

    A. Madan, P. Yashar, S.A. Barnett, and M. Shinn, Thin Solid Films 302 (1997) p. 147.

    CAS  Article  Google Scholar 

  23. 22.

    D. Josell and F. Spaepen, Acta Metall. Mater. 41 (1993) p. 3007.

    CAS  Article  Google Scholar 

  24. 23.

    R. Bruinsma and A. Zangwill, J. Phys. 47 (1986) p. 2055.

    CAS  Article  Google Scholar 

  25. 24.

    D.M. Wood and A. Zunger, Phys. Rev. B 40 (1989) p. 4062.

    CAS  Article  Google Scholar 

  26. 25.

    M.J. Hall, B.J. Hickey, M.A. Howson, M.J. Walker, J. Xu, D. Greig, and N. Wiser, Phys. Rev. B 47 (19) (1993) p. 12785.

    CAS  Article  Google Scholar 

  27. 26.

    F.J. Lamelas, C.H. Lee, H. He, W. Vavra, and R. Clarke, Phys. Rev. B 40 (8) (1989) p. 5837.

    CAS  Article  Google Scholar 

  28. 27.

    D. Li, X.-W. Lin, S.-C. Cheng, V.P. Dravid, Y.-W. Chung, M.-S. Wong, and W.D. Sproul, Appl. Phys. Lett. 68 (9) (1996) p. 1211.

    CAS  Article  Google Scholar 

  29. 28.

    M.L. Wu, M.U. Guruz, V.P. Dravid, Y.W. Chung, S. Anders, F.L. Freire Jr., and G. Mariotto, Appl. Phys. Lett. 76 (19) (2000) p. 2692.

    CAS  Article  Google Scholar 

  30. 29.

    P. Yashar, X. Chu, S.A. Barnett, J. Rechner, Y.Y. Wang, M.-S. Wong, and W.D. Sproul, Appl. Phys. Lett. 72 (8) (1998) p. 987.

    CAS  Article  Google Scholar 

  31. 30.

    N.E. Christensen and I. Gorczyca, Phys. Rev. B 50 (1994) p. 4397.

    CAS  Article  Google Scholar 

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Barnett, S.A., Madan, A., Kim, I. et al. Stability of Nanometer-Thick Layers in Hard Coatings. MRS Bulletin 28, 169–172 (2003).

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  • annealing
  • hardness testing
  • superhard coating materials
  • thin films