Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-24T20:08:38.370Z Has data issue: false hasContentIssue false

Time-dependent incipient plasticity in Ni3Al as observed in nanoindentation

Published online by Cambridge University Press:  03 March 2011

P.C. Wo
Affiliation:
Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
L. Zuo
Affiliation:
Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
A.H.W. Ngan*
Affiliation:
Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

The time-dependent characteristics of incipient plasticity in Ni3Al during nanoindentation in the subcritical load regime were investigated statistically. The waiting time for incipient plasticity to occur at constant load was found to follow a Poisson-like distribution, with the peak shifting toward zero holding time as the load increased and eventually becoming an exponential distribution when the load was close to a critical value. The observed distribution of the strain burst waiting time at loads smaller than the critical value was inconsistent with the picture in which dislocations nucleated homogeneously out of the perfect crystal. The kinetics for the occurrence of strain burst in this case is thought to be governed by the accumulative growth of nucleation precursors.

Type
Articles
Copyright
Copyright © Materials Research Society 2005

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.Asif, S.A. Syed and Pethica, J.B.: Nanoindentation creep of single-crystal tungsten and gallium arsenide. Philos. Mag. A 76, 1105 (1997).CrossRefGoogle Scholar
2.Gerberich, W.W., Nelson, J.C., Lilleodden, E.T., Anderson, R. and Wyrobek, J.T.: Indentation induced dislocation nucleation: The initial yield point. Acta Mater. 44, 3585 (1996).CrossRefGoogle Scholar
3.Chiu, Y.L. and Ngan, A.H.W.: Time-dependent characteristics of incipient plasticity in nanoindentation of a Ni3Al single crystal. Acta Mater. 50, 1599 (2002).CrossRefGoogle Scholar
4.Chiu, Y.L. and Ngan, A.H.W.: A TEM investigation on indentation plastic zones in Ni3Al (Cr, B) single crystals. Acta Mater. 50, 2677 (2002).CrossRefGoogle Scholar
5.Robertson, C.F. and Fivel, M.C.: A study of the submicron intent-induced plastic deformation. J. Mater. Res. 14, 2251 (1999).CrossRefGoogle Scholar
6.Li, J., Ngan, A.H.W. and Gumbsch, P.: Atomic modelling of mechanical behaviour. Acta Mater. 51, 5711 (2003).CrossRefGoogle Scholar
7.Gerberich, W.W., Venkataraman, S.K., Huang, H., Harvey, S.E. and Kohlstedt, D.L.: The injection of plasticity by millinewton contacts. Acta Mater. 43, 1569 (1995).CrossRefGoogle Scholar
8.Wo, P.C. and Ngan, A.H.W.: Incipient plasticity during nanoscratch in Ni3Al. Philos. Mag. 84, 3145 (2004).CrossRefGoogle Scholar
9.Schuh, C.A. and Lund, A.C.: Application of nucleation theory to the rate dependence of incipient plasticity during nanoindentation. J. Mater. Res. 19, 2152 (2004).CrossRefGoogle Scholar
10.Li, H. and Ngan, A.H.W.: Size effects of nanoindentation creep. J. Mater. Res. 19, 513 (2004).CrossRefGoogle Scholar
11.Liang, H.Y., Woo, C.H., Huang, H., Ngan, A.H.W. and Yu, T.X.: Dislocation nucleation in the initial stage during nanoindentation. Philos. Mag. 83, 3609 (2003).CrossRefGoogle Scholar
12.Johnson, K.L.: Contact Mechanics(Cambridge Univ. Press, Cambridge, U.K., 1987), p. 93.Google Scholar
13.Voter, A.F. and Chen, S.P.: in Characterization of Defects in Materials, edited by Siegel, R.W., Weertman, J.R., and Sinclair, R. (Mater. Res. Soc. Symp. Proc. 82, Pittsburgh, PA, 1987), p. 175.Google Scholar
14.Vlassak, J.J. and Nix, W.D.: Measuring the elastic properties of anisotropic materials by means of indentation experiments. J. Mech. Phys. Solids 42, 1223 (1994).CrossRefGoogle Scholar
15.Woodcock, L.V.: Isothermal molecular dynamics calculations for liquid salts chem. Phys. Lett. 10, 257 (1970).Google Scholar
16.Horstemeyer, M.F., Baskes, M.I. and Plimpton, S.T.: Length scale and time scale effects on the plastic flow of fcc metals. Acta Mater. 49, 4363 (2001).CrossRefGoogle Scholar
17.Ngan, A.H.W., Wen, M. and Woo, C.H.: Atomistic simulation of Paidar-Pope-Vitek lock formation in Ni3Al. Comput. Mater. Sci. 29, 259 (2004).CrossRefGoogle Scholar