Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-28T01:13:37.038Z Has data issue: false hasContentIssue false
  • English
  • Français

Accurate determination of the mechanical properties of thin aluminum films deposited on sapphire flats using nanoindentations

Published online by Cambridge University Press:  31 January 2011

Y. Y. Lim ,
M. M. Chaudhri  and
Y. Enomoto
Y. Y. Lim
Affiliation:
Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, United Kingdom
M. M. Chaudhri
Affiliation:
Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, United Kingdom
Y. Enomoto
Affiliation:
Mechanical Engineering Laboratory, Namiki 1–2, Tsukuba, Ibaraki 305, Japan
Get access

Abstract

Nanoindentations using a Berkovich diamond indenter have been made on 1, 2, and 5 μm thick 99.99% purity polycrystalline aluminum films thermally evaporated in vacuum on to 2 mm thick R-cut polished sapphire flats. The projected contact areas of the residual indentations were estimated from the unloading load-displacement curves, and some of the indentations were imaged with an atomic force microscope (AFM). It was found that a large majority of indents showed material pileup, and the projected areas of these indents, as measured with the AFM, were up to 50% greater than those calculated from the unloading curves. This discrepancy between the calculated and directly measured indentation areas has a strong influence on the derived values of Young's modulus and hardness of the aluminum films. Using a new analytical model, Young's modulus of the aluminum films has been determined to be in the range of 50–70 GPa, independent of the relative indentation depth. The composite nanohardness of the 1 and 2 μm thick films was found to have a load-independent value of 1 GPa, whereas the composite nanohardness of the 5 μm film decreased from 1 to 0.7 Gpa with increasing indenter penetration. Finally, it has been suggested that in order to improve the accuracy with which the mechanical properties of thin films or bulk specimens can be determined by nanoindentation techniques, the projected contact areas should be measured by direct methods, such as atomic force microscopy.

Type
Articles
Information
Journal of Materials Research , Volume 14 , Issue 6 , June 1999 , pp. 2314 - 2327
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Alekhin, V. P., Berlin, G. S., Isaev, A. V., Kalei, G. N., Merkulov, V. A., Skvortsov, V. N., Ternovskii, A. P., Krushchov, M.M., Shnyrev, G. D., and Shorshorov, M. Kh., Industrial Laboratory 38, 619 (1972).Google Scholar
2.Bulychev, S. I., Alekhin, V. P., Shorshorov, M. Kh., Ternovskii, A. P., and Shnyrev, G. D., Industrial Laboratory 41, 1409 (1975).Google Scholar
3.Galanov, B. A., Grigor'ev, O. N., Milman, Yu. V., and Ragozin, I. P., Strength Mater. 11, 624 (1984).Google Scholar
4.Loubet, J. L., Georges, J. M., Marchesini, O., and Meille, G., J. Tribology 106, 43 (1984).CrossRefGoogle Scholar
5.Loubet, J. L., Georges, J. M., and Meille, G., in Microindentation Techniques in Materials Science and Engineering, edited by Blau, P. J. and Lawn, B.R., ASTM Spec. Tech. Publ. 889 (ASTM, Philadelphia, PA, 1986), p. 72.Google Scholar
6.Doerner, M. F. and Nix, W. D., J. Mater. Res. 1, 601 (1986).CrossRefGoogle Scholar
7.Doerner, M. F., Gardner, D. S., and Nix, W. D., J. Mater. Res. 1, 845 (1986).CrossRefGoogle Scholar
8.Ross, J. D. J., Pollock, H. M., Pivin, J. C., and Takadoum, J., Thin Solid Films 148, 171 (1987).CrossRefGoogle Scholar
9.Wu, T.W., Moshref, M., and Alexopoulos, P. S., Thin Solid Films 187, 295 (1990).CrossRefGoogle Scholar
10.Swain, M. V. and Menčik, J., Thin Solid Films 253, 204 (1994).CrossRefGoogle Scholar
11.Menčik, J., Munz, D., Quandt, E., Weppelmann, E.R., and Swain, M.V., J. Mater. Res. 12, 2475 (1997).CrossRefGoogle Scholar
12.Bückle, H., in Science of Hardness Testing and Its Research Applications, edited by Westbrook, J. H. and Conrad, H. (American Society for Metals, Metals Park, OH, 1971), pp. 453–494.Google Scholar
13.Kim, M. T., Thin Solid Films 283, 12 (1996).CrossRefGoogle Scholar
14.Yoffe, E.H., Philos. Mag. Lett. 77, 69 (1998).CrossRefGoogle Scholar
15.Oliver, W.C. and Pharr, G. M., J. Mater. Res. 7, 1564 (1992).CrossRefGoogle Scholar
16.Hainsworth, S. V., Chandler, H. W., and Page, T. F., J. Mater. Res. 11, 1987 (1996).CrossRefGoogle Scholar
17.Sneddon, I. N., Int. J. Eng. Sci. 3, 47 (1965).CrossRefGoogle Scholar
18.Chaudhri, M. M. and Phillips, M. A., Philos. Mag. A 62, 1 (1990).CrossRefGoogle Scholar
19.Tsui, T.Y., Oliver, W. C., and Pharr, G. M., J. Mater. Res. 11, 752 (1996).CrossRefGoogle Scholar
20.Chaudhri, M. M. and Winter, M., J. Phys. D 370, 21 (1988).Google Scholar
21.McElhaney, K. W., Vlassak, J. J., and Nix, W. D., J. Mater. Res. 13, 1300 (1998).CrossRefGoogle Scholar
22.Bec, S., Tonck, A., Georges, J. M., Georges, E., and Loubet, J. L., Philos. Mag. A 74, 1061 (1996).CrossRefGoogle Scholar
23.Lim, Y. Y., Bushby, A. J., and Chaudhri, M. M., in Fundamentals of Nanoindentation and Nanotribology, edited by Moody, N.R., Gerberich, W. W., Burnham, N., and Baker, S. P. (Mater. Res. Soc. Symp. Proc. 522, Warrendale, PA, 1998), p. 145.Google Scholar
24.Kaye, G. W. C. and Laby, T. H., Tables of Physical and Chemical Constants, 16th ed. (Longman, London, 1995), p. 44.Google Scholar
25.Gao, H., Chiu, C., and Lee, J., Int. J. Solids Struct. 29, 2471 (1992).Google Scholar
26.Chaudhri, M. M., Acta Mater. 46, 3047 (1998).CrossRefGoogle Scholar