Abstract
Indentation testing is a convenient means to study mechanical properties of thin coatings. We suggest a new method to identify the viscoplastic behavior of a polymer by using the force-penetration curves during nano-indentation testing performed with two indenter shapes. During loading, the load applied by the indenter and the penetration depth have been measured. These force-penetration curves have been compared to the load computed by using the finite element method with a two dimensional software. The viscoplastic behavior of the polymer is modeled with the G'sell-Jonas law. The main particularity of this law is the modeling of the large strain-hardening at large strains. The unknown parameters of this law have been obtained by fitting computed and experimental force-penetration curves. We have identified each parameter independently of the others by taking into account the indenter tip defect. The nano-indentation tests have been performed with three strain rates and with two indenter shapes: a Berkovich indenter and a cone with a semi angle of θ = 30° and a tip radius. In this paper, the polymer is a polycarbonate. Several authors have made rheological tests on this polymer. The true strain-true stress curve obtained with our method is in good agreement with the compression curve.
Similar content being viewed by others
References
D. Tabor, “The Hardness of Metals” (Clarendon Press, Oxford, 1951).
N. R. Chitkara and M. A. Butt, Int.J.Mech.Sci. 34 (1992) 849.
P. Laval, PhD thesis, Ecole Nationale Sup´erieure des Mines de Paris, 1995.
K. L. Johnson, J.Mech.Phys.Solids 18 (1970) 115.
W. C. Oliver and G. M. Pharr, J.Mater.Res. 7 (1992) 1564.
B. J. Briscoe and K. S. Sebastian, Proc.R.Soc.Lond. A 452 (1996) 439.
A. K. Bhattacharya and W. D. Nix, Int.J.Solids Structures 24 (1988) 881.
Y.-T. Cheng and C.-M. Cheng, J.Mater.Res. 14 (1999) 3493.
T. A. Venkatesh, K. J. Vliet, A. E. Giannakopoulos and S. Suresh, Scripta Materialia 42 (2000) 833.
N. Tardieu, PhD thesis, Ecole Polytechnique, 2000.
E. S. Berkovich, Industrial Diamond Review 11 (1951) 129.
S. Matsuoka, in “Failure of Plastics, ” edited by W. Brostow and R. D. Corneliussen (Hanser Publishers, Munich, 1986) p. 24.
N. Brown, in “Failure of Plastics, ” edited by W. Brostow and R. D. Corneliussen (Hanser Publishers, Munich, 1986) p. 98.
B. N. Lucas, W. C. Oliver, G. M. Pharr and J.-L. Loubet, in “Stresses and Mechanical Properties, ” Vol. VI, edited by W.-W. Gerberich, H. Gao, J.-E. Sundgren and S.-P. Baker (Materials Research Society, 1996) p. 233.
R. F. Staats-WESTOVER and W. J. Vroom, Soc.Plant Engrs. 25 (1968) 8.
M. L. Bisilliat, PhD thesis, Ecole Nationale Sup´erieure des Mines de Paris (1997).
C. G'sell and J. J. Jonas, J.Mater.Sci. 14 (1979) 583.
M. C. Boyce and E. M. Arruda, Polymer Engineering and Science 30 (1990) 1288.
J.-L. Bucaille, PhD thesis, Ecole Nationale Sup´erieure des Mines de Paris (2001).
J. Goddard and H. Wilman, Wear 5 (1962) 114.
B. J. Briscoe, P. D. Evans, S. K. Biswas and S. K. Sinha, Trib.Int. 29 (1996) 93.
C. Ramond-ANGÉLÉLIS, PhD thesis, Ecole Nationale Sup´erieure des Mines de Paris (1998).
D. M. Marsh, Proc.R.Soc. A 279 (1964) 420.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Bucaille, J.L., Felder, E. & Hochstetter, G. Identification of the viscoplastic behavior of a polycarbonate based on experiments and numerical modeling of the nano-indentation test. Journal of Materials Science 37, 3999–4011 (2002). https://doi.org/10.1023/A:1019644630927
Issue Date:
DOI: https://doi.org/10.1023/A:1019644630927