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Heterogeneous dislocation nucleation from surfaces and interfaces as governing plasticity mechanism in nanoscale metals

Published online by Cambridge University Press:  22 November 2011

Andrew T. Jennings*
Affiliation:
Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125
Julia R. Greer*
Affiliation:
Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

We report the results of constant strain rate experiments on electroplated, single crystalline copper pillars with diameters between 75 and 525 nm. At slow strain rates, 10−3 s−1, pillar diameters with 150 nm and above show a size-dependent strength similar to previous reports. Below 150 nm, we find that the size effect vanishes as the strength transitions to a relatively size-independent regime. Strain rate sensitivity and activation volume are determined from uniaxial compression tests at different strain rates and corroborate a deformation mechanism change. These results are discussed in the framework of recent in situ transmission electron microscopy experiments observing two distinct deformation mechanisms in pillars and thin films on flexible substrates: partial dislocation nucleation from stress concentrations in smaller structures and single arm source operation in larger samples. Models attempting to explain these different size-dependent regimes are discussed in relation to these experiments and existing literature revealing further insights into the likely small-scale deformation mechanisms.

Type
Invited Feature Papers
Copyright
Copyright © Materials Research Society 2011

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References

REFERENCES

1.Taylor, G.I.: Plastic strain in metals. J. Inst. Met. 62, 307 (1938).Google Scholar
2.Hall, E.O.: The deformation and ageing of mild steel. 3. Discussion of results. Proc. Phys. Soc. London, Sect. B 64, 747 (1951).CrossRefGoogle Scholar
3.Petch, N.J.: The cleavage strength of polycrystals. J. Iron Steel Inst. 174, 25 (1953).Google Scholar
4.Dehm, G.: Miniaturized single-crystalline fcc metals deformed in tension: New insights in size-dependent plasticity. Prog. Mater. Sci. 54, 664 (2009).CrossRefGoogle Scholar
5.Uchic, M.D., Shade, P.A., and Dimiduk, D.M.: Plasticity of micrometer-scale single crystals in compression. Annu. Rev. Mater. Res. 39, 361 (2009).CrossRefGoogle Scholar
6.Kraft, O., Gruber, P., Mönig, R., and Weygand, D.: Plasticity in confined dimensions. Annu. Rev. Mater. Res. 40, 293 (2010).CrossRefGoogle Scholar
7.Greer, J.R. and De Hosson, J.T.M.: Review: Plasticity in small-sized metallic systems: Intrinsic versus extrinsic size effect. Prog. Mater. Sci. 56, 654 (2011).CrossRefGoogle Scholar
8.Nix, W.D., Greer, J.R., Feng, G., and Lilleodden, E.T.: Deformation at the nanometer and micrometer length scales: Effects of strain gradients and dislocation starvation. Thin Solid Films 515, 3152 (2007).CrossRefGoogle Scholar
9.Dimiduk, D.M., Uchic, M.D., and Parthasarathy, T.A.: Size-affected single-slip behavior of pure nickel microcrystals. Acta Mater. 53, 4065 (2005).CrossRefGoogle Scholar
10.Uchic, M.D., Dimiduk, D.M., Florando, J.N., and Nix, W.D.: Sample dimensions influence strength and crystal plasticity. Science 305, 986 (2004).CrossRefGoogle ScholarPubMed
11.Greer, J.R., Oliver, W.C., and Nix, W.D.: Size dependence of mechanical properties of gold at the micron scale in the absence of strain gradients. Acta Mater. 53, 1821 (2005).CrossRefGoogle Scholar
12.Volkert, C.A. and Lilleodden, E.T.: Size effects in the deformation of sub-micron Au columns. Philos. Mag. 86, 5567 (2006).CrossRefGoogle Scholar
13.Gruber, P.A., Solenthaler, C., Arzt, E., and Spolenak, R.: Strong single-crystalline Au films tested by a new synchrotron technique. Acta Mater. 56, 1876 (2008).CrossRefGoogle Scholar
14.Oh, S.H., Legros, M., Kiener, D., Gruber, P., and Dehm, G.: In situ TEM straining of single crystal Au films on polyimide: Change of deformation mechanisms at the nanoscale. Acta Mater. 55, 5558 (2007).CrossRefGoogle Scholar
15.Parthasarathy, T.A., Rao, S.I., Dimiduk, D.M., Uchic, M.D., and Trinkle, D.R.: Contribution to size effect of yield strength from the stochastics of dislocation source lengths in finite samples. Scr. Mater. 56, 313 (2007).CrossRefGoogle Scholar
16.Rao, S., Dimiduk, D., Tang, M., Parthasarathy, T., Uchic, M., and Woodward, C.: Estimating the strength of single-ended dislocation sources in micron-sized single crystals. Philos. Mag. 87, 4777 (2007).CrossRefGoogle Scholar
17.Rao, S.I., Dimiduk, D.M., Parthasarathy, T.A., Uchic, M.D., Tang, M., and Woodward, C.: Athermal mechanisms of size-dependent crystal flow gleaned from three-dimensional discrete dislocation simulations. Acta Mater. 56, 3245 (2008).CrossRefGoogle Scholar
18.Norfleet, D.M., Dimiduk, D.M., Polasik, S.J., Uchic, M.D., and Mills, M.J.: Dislocation structures and their relationship to strength in deformed nickel microcrystals. Acta Mater. 56, 2988 (2008).CrossRefGoogle Scholar
19.von Blanckenhagen, B., Arst, E., and Gumbsch, P.: Discrete dislocation simulation of plastic deformation in metal thin films. Acta Mater. 52, 773 (2004).CrossRefGoogle Scholar
20.Tang, H., Schwarz, K.W., and Espinosa, H.D.: Dislocation escape-related size effects in single-crystal micropillars under uniaxial compression. Acta Mater. 55, 1607 (2007).CrossRefGoogle Scholar
21.Tang, H., Schwarz, K.W., and Espinosa, H.D.: Dislocation-source shutdown and the plastic behavior of single-crystal micropillars. Phys. Rev. Lett. 100, 185503 (2008).CrossRefGoogle ScholarPubMed
22.Weygand, D., Poignant, M., Gumbsch, P. and Kraft, O.: Three-dimensional dislocation dynamics simulation of the influence of sample size on the stress-strain behavior of fcc single-crystalline pillars. Mater. Sci. Eng., A 48384, 188 (2008).CrossRefGoogle Scholar
23.Senger, J., Weygand, D., Gumbsch, P., and Kraft, O.: Discrete dislocation simulations of the plasticity of micro-pillars under uniaxial loading. Scr. Mater. 58, 587 (2008).CrossRefGoogle Scholar
24.Oh, S.H., Legros, M., Kiener, D., and Dehm, G.: In situ observation of dislocation nucleation and escape in a submicrometre aluminium single crystal. Nat. Mater. 8, 95 (2009).CrossRefGoogle Scholar
25.Jennings, A.T., Li, J., and Greer, J.R.: Emergence of strain rate sensitivity in Cu nano-pillars: Transition from dislocation multiplication to dislocation nucleation. Acta Mater. 59, 5627 (2011).CrossRefGoogle Scholar
26.Richter, G., Hillerich, K., Gianola, D.S., Mönig, R., Kraft, O., and Volkert, C.A.: Ultrahigh strength single crystalline nanowhiskers grown by physical vapor deposition. Nano Lett. 9, 3048 (2009).CrossRefGoogle ScholarPubMed
27.Zheng, H., Cao, A., Weinberger, C., Huang, J.Y., Du, K., Wang, J., Ma, Y., Xia, Y., and Mao, S.X.: Discrete plasticity in sub-10-nm-sized gold crystals. Nat. Commun. 1, 144 (2010).CrossRefGoogle ScholarPubMed
28.Zhu, T., Li, J., Samanta, A., Leach, A., and Gall, K.: Temperature and strain-rate dependence of surface dislocation nucleation. Phys. Rev. Lett. 100, 025502 (2008).CrossRefGoogle ScholarPubMed
29.Deng, C. and Sansoz, F.: Size-dependent yield stress in twinned gold nanowires mediated by site-specific surface dislocation emission. App. Phys. Lett. 95, 091914 (2009).CrossRefGoogle Scholar
30.Burek, M.J. and Greer, J.R.: Fabrication and microstructure control of nanoscale mechanical testing specimens via electron beam lithography and electroplating. Nano Lett. 10, 69 (2010).CrossRefGoogle ScholarPubMed
31.Jennings, A.T., Burek, M.J., and Greer, J.R.: Microstructure versus size: Mechanical properties of electroplated single crystalline Cu nanopillars. Phys. Rev. Lett. 104, 135503 (2010).CrossRefGoogle ScholarPubMed
32.Jennings, A.T. and Greer, J.R.: Tensile deformation of electroplated copper nanopillars. Philos. Mag. 91, 1108 (2011).CrossRefGoogle Scholar
33.Bei, H., Shim, S., George, E.P., Miller, M.K., Herbert, E.G., and Pharr, G.M.: Compressive strengths of molybdenum alloy micro-pillars prepared using a new technique. Scr. Mater. 57, 397 (2007).CrossRefGoogle Scholar
34.Bei, H., Shim, S., Pharr, G.M., and George, E.P.: Effects of pre-strain on the compressive stress-strain response of Mo-alloy single-crystal micropillars. Acta Mater. 56, 4762 (2008).CrossRefGoogle Scholar
35.Shim, S., Bei, H., Miller, M.K., Pharr, G.M., and George, E.P.: Effects of focused-ion-beam milling on the compressive behavior of directionally solidified micropillars and the nanoindentation response of an electropolished surface. Acta Mater. 57, 503 (2009).CrossRefGoogle Scholar
36.Buzzi, S., Dietiker, M., Kunze, K., Spolenak, R., and Loffler, J.F.: Deformation behavior of silver submicrometer-pillars prepared by nanoimprinting. Philos. Mag. 89, 869 (2009).CrossRefGoogle Scholar
37.Dietiker, M., Buzzi, S., Pigozzi, G., Loffler, J.F., and Spolenak, R.: Deformation behavior of gold nano-pillars prepared by nanoimprinting and focused-ion-beam milling. Acta Mater. 59, 2180 (2011).CrossRefGoogle Scholar
38.Kiener, D. and Minor, A.M.: Source-controlled yield and hardening of Cu(100) studied by in situ transmission electron microscopy. Acta Mater. 59, 1328 (2011).CrossRefGoogle Scholar
39.Lowry, M.B., Kiener, D., LeBlanc, M.M., Chisholm, C., Florando, J.N., Morris, J.W., and Minor, A.M.: Achieving the ideal strength in annealed molybdenum nanopillars. Acta Mater. 58, 5160 (2010).CrossRefGoogle Scholar
40.Greer, J.R., Jang, D.C., Kim, J.Y., and Burek, M.J.: Emergence of new mechanical functionality in materials via size reduction. Adv. Funct. Mater. 19, 2880 (2009).CrossRefGoogle Scholar
41.Kocks, U.F., Argon, A.S., and Ashby, M.F.: Thermodynamics and kinetics of slip. Prog. Mater. Sci. 19, 1 (1975).Google Scholar
42.Nix, W.D. and Lee, S.W.: Micro-pillar plasticity controlled by dislocation nucleation at surfaces. Philos. Mag. 91, 1084 (2011).CrossRefGoogle Scholar
43.Ng, K.S. and Ngan, A.H.W.: Stochastic theory for jerky deformation in small crystal volumes with pre-existing dislocations. Philos. Mag. 88, 677 (2008).CrossRefGoogle Scholar
44.Brenner, S.S.: Tensile strength of whiskers. J. Appl. Phys. 27, 1484 (1956).CrossRefGoogle Scholar
45.Lu, Y., Huang, J.Y., Wang, C., Sun, S.H., and Lou, J.: Cold welding of ultrathin gold nanowires. Nat. Nanotechnol. 5, 218 (2010).CrossRefGoogle ScholarPubMed
46.Shan, Z.W., Mishra, R.K., Syed Asif, S.A., Warren, O.L., and Minor, A.M.: Mechanical annealing and source-limited deformation in submicrometre-diameter Ni crystals. Nat. Mater. 7, 115 (2008).CrossRefGoogle ScholarPubMed
47.Weinberger, C.R. and Cai, W.: Surface-controlled dislocation multiplication in metal micropillars. Proc. Natl. Acad. Sci. USA 105, 14304 (2008).CrossRefGoogle ScholarPubMed
48.Nix, W.: Mechanical properties of thin films. Metall. Mater. Trans. A 20, 2217 (1989).CrossRefGoogle Scholar
49.Freund, L.B.: The stability of a dislocation threading a strained layer on a substrate. J. Appl. Mech. 54, 553 (1987).CrossRefGoogle Scholar
50.Greer, J.R. and Nix, W.D.: Nanoscale gold pillars strengthened through dislocation starvation. Phys. Rev. B 73, 245410 (2006).CrossRefGoogle Scholar
51.Chen, M.W., Ma, E., Hemker, K.J., Sheng, H.W., Wang, Y.M., and Cheng, X.M.: Deformation twinning in nanocrystalline aluminum. Science 300, 1275 (2003).CrossRefGoogle ScholarPubMed
52.Aubry, S., Kang, K., Ryu, S., and Cai, W.: Energy barrier for homogeneous dislocation nucleation: Comparing atomistic and continuum models. Scr. Mater. 64, 1043 (2011).CrossRefGoogle Scholar
53.Beltz, G.E. and Freund, L.B.: On the nucleation of dislocations at a crystal surface. Phys. Status Solidi B 180, 303 (1993).CrossRefGoogle Scholar
54.Weinberger, C.R., Jennings, A.T., Kang, K. and Greer, J.R.: Atomistic simulations and continuum modeling of dislocation nucleation and strength in gold nanowires. J. Mech. Phys. Solids (2011, doi:10.1016/j.jmps.2011.09.010).Google Scholar
55.Estrin, Y., Kim, H.S., and Nabarro, F.R.N.: A comment on the role of Frank-Read sources in plasticity of nanomaterials. Acta Mater. 55, 6401 (2007).CrossRefGoogle Scholar
56.Shemenski, R.M.: Thermal activation of a dislocation source. ASM Trans. Q. 58, 360 (1965).Google Scholar
57.Conrad, H.: Grain size dependence of the plastic deformation kinetics in Cu. Mater. Sci. Eng., A 341, 216 (2003).CrossRefGoogle Scholar
58.Zhu, T. and Li, J.: Ultra-strength materials. Prog. Mater. Sci. 55, 710 (2010).CrossRefGoogle Scholar
59.Li, X.Y., Wei, Y.J., Lu, L., Lu, K., and Gao, H.J.: Dislocation nucleation governed softening and maximum strength in nano-twinned metals. Nature 464, 877 (2010).CrossRefGoogle ScholarPubMed
60.Van Swygenhoven, H., Derlet, P.M., and Froseth, A.G.: Stacking fault energies and slip in nanocrystalline metals. Nat. Mater. 3, 399 (2004).CrossRefGoogle ScholarPubMed