Ultra-Hard Nanostructured Al-Si Thin Films


Article Preview

We show that it is possible to use high rate co-evaporation of Al and Si onto room temperature substrates to achieve a novel two-phase nanoscale microstructure. These nanocomposites have a hardness as high as 4GPa (Al-23at.%Si), and display noticeable plasticity. Films with compositions of Al-12at.%Si and pure Al (used as baseline) were analyzed using transmission electron microscopy (TEM). The scale of the Al-12at.%Si microstructure is an order of magnitude finer compared to that of pure Al films. It consists of a dense distribution of spherical nanoscale Si particles separating irregularly-shaped small Al grains. These new structures may have a mechanical performance advantage over conventional single phase nanomaterials due to the role of the dispersed hard phase in promoting strain hardening.



Edited by:

Dragan P. Uskokovic, Slobodan K. Milonjic, Djan I. Rakovic




V. Radmilović et al., "Ultra-Hard Nanostructured Al-Si Thin Films", Materials Science Forum, Vol. 494, pp. 13-18, 2005

Online since:

September 2005




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

[2] G. S. Was and T. Foecke, Thin Solid Films, 286 (1996), p.1.

[3] B. M. Clemens, H. Kung and S. A. Barnett, Mater. Res. Soc. Bull., 24 (1999), p.20.

[4] J. R. Weertman in Nanostructured Materials, C. C. Koch editor, Noyes Data Corporation/Noyes Publications, pp.397-422, (2000).

[5] A. Kelly and R. B. Nicholson, Prog. Metal. Phys., 10 (1963), p.151.

[6] M. F. Ashby, Phil. Mag., 14 (1966), p.1157.

[7] L. M. Brown and D. R. Clarke, Acta Metall., 23 (1975), p.821.

[8] K. Tanaka and T. Mori, Acta Metall., 18 (1970), p.931.

[9] C.C. Koch, Scripta Mater., 49 (2003), p.657.

[10] E. Hornbogen, A. K. Mukhopadhyay and E. A. Starke, Zeitschrift fur Metallkunde, 83 (1992), p.577.

[11] D. Mitlin, V. Radmilovic and J. W. Morris, Jr., Materials Science and Engineering A., 301 (2001), p.231.

[12] R. Saha and W. D. Nix, Acta Mater., 50 (2002), p.23.