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Importance of dislocation pile-ups on the mechanical properties and the Bauschinger effect in microcantilevers

Published online by Cambridge University Press:  10 March 2015

M.W. Kapp
Affiliation:
Montanuniversität Leoben, Department Materialphysik, Leoben 8700, Austria; and Erich Schmid Institute of Material Science, Austrian Academy of Sciences, Leoben 8700, Austria
C. Kirchlechner*
Affiliation:
Max-Planck-Institut für Eisenforschung, Düsseldorf 40237, Germany; and Montanuniversität Leoben, Department Materialphysik, Leoben 8700, Austria
R. Pippan
Affiliation:
Erich Schmid Institute of Material Science, Austrian Academy of Sciences, Leoben 8700, Austria
G. Dehm
Affiliation:
Max-Planck-Institut für Eisenforschung, Düsseldorf 40237, Germany; Montanuniversität Leoben, Department Materialphysik, Leoben 8700, Austria; and Erich Schmid Institute of Material Science, Austrian Academy of Sciences, Leoben 8700, Austria
*
a)Address all correspondence to this author. e-mail: kirchlechner@mpie.de
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Abstract

Copper microcantilevers were produced by focused ion beam milling and tested in situ using a scanning electron microscope. To provide different interfaces for piling up dislocations, cantilevers were fabricated to be single crystalline, bicrystalline, or single crystalline with a slit in the region of the neutral axis. The aim of the experiment was to study the influence of dislocation pile-ups on (i) strength and (ii) Bauschinger effects in micrometer-sized, focused ion beam milled bending cantilevers. The samples were loaded monotonically for several times under displacement control. Even though the cantilevers exhibited the same nominal strain gradient the strength varied by 34% within the three cantilever geometries. The Bauschinger effect can be promoted and prohibited by the insertion of different interfaces.

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Articles
Copyright
Copyright © Materials Research Society 2015 

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References

REFERENCES

Motz, C., Schöberl, T., and Pippan, R.: Mechanical properties of micro-sized copper bending beams machined by the focused ion beam technique. Acta Mater. 53(15), 4269 (2005).CrossRefGoogle Scholar
Gong, J. and Wilkinson, A.J.: A microcantilever investigation of size effect, solid-solution strengthening and second-phase strengthening for <a> prism slip in alpha-Ti. Acta Mater. 59(15), 5970 (2011).Google Scholar
Demir, E., Raabe, D., and Roters, F.: The mechanical size effect as a mean-field breakdown phenomenon: Example of microscale single crystal beam bending. Acta Mater. 58(5), 1876 (2010).CrossRefGoogle Scholar
Kiener, D., Motz, C., Grosinger, W., Weygand, D., and Pippan, R.: Cyclic response of copper single crystal micro-beams. Scr. Mater. 63(5), 500 (2010).Google Scholar
Kirchlechner, C., Grosinger, W., Kapp, M.W., Imrich, P.J., Micha, J.S., Ulrich, O., Keckes, J., Dehm, G., and Motz, C.: Investigation of reversible plasticity in a micron-sized, single crystalline copper bending beam by x-ray μLaue diffraction. Philos. Mag. 92(25–27), 3231 (2012).Google Scholar
Kraft, O., Gruber, P.A., Mönig, R., and Weygand, D.: Plasticity in confined dimensions. Annu. Rev. Mater. Res. 40, 293 (2010).CrossRefGoogle Scholar
Greer, J.R. and De Hosson, J.T.M.: Plasticity in small-sized metallic systems: Intrinsic versus extrinsic size effect. Prog. Mater. Sci. 56(6), 654 (2011).Google Scholar
Fleck, N.A., Muller, G.M., Ashby, M.F., and Hutchinson, J.W.: Strain gradient plasticity: Theory and experiment. Acta Metall. Mater. 42(2), 475 (1994).Google Scholar
Stölken, J.S. and Evans, A.G.: A microbend test method for measuring the plasticity length scale. Acta Mater. 46(14), 5109 (1998).Google Scholar
Bushby, A.J. and Dunstan, D.J.: Size effects in yield and plasticity under uniaxial and non-uniform loading: Experiment and theory. Philos. Mag. 91(7–9), 1037 (2010).Google Scholar
Uchic, M.D., Dimiduk, D.M., Florando, J.N., and Nix, W.D.: Sample dimensions influence strength and crystal plasticity. Science 305(5686), 986 (2004).CrossRefGoogle ScholarPubMed
Volkert, C.A. and Lilleodden, E.T.: Size effects in the deformation of sub-micron Au columns. Philos. Mag. 86(33–35), 5567 (2006).CrossRefGoogle Scholar
Kiener, D., Grosinger, W., Dehm, G., and Pippan, R.: A further step towards an understanding of size-dependent crystal plasticity: In situ tension experiments of miniaturized single-crystal copper samples. Acta Mater. 56(3), 580 (2008).Google Scholar
Kim, J.Y., Jong, D.C., and Greer, J.R.: Tensile and compressive behavior of tungsten, molybdenum, tantalum and niobium at the nanoscale. Acta Mater. 58(7), 2355 (2010).Google Scholar
Motz, C., Weygand, D., Senger, J., and Gumbsch, P.: Initial dislocation structures in 3-D discrete dislocation dynamics and their influence on microscale plasticity. Acta Mater. 56(6), 1942 (2008).Google Scholar
Suresh, S.: Fatigue of Materials (Cambridge University Press, Cambridge, 1998).CrossRefGoogle Scholar
Pedersen, O.B., Brown, L.M., and Stobbs, W.M.: The Bauschinger effect in copper. Acta Metall. 29(11), 1843 (1981).CrossRefGoogle Scholar
Rajagopalan, J., Rentenberger, C., Peter Karnthaler, H., Dehm, G., and Saif, M.T.A.: In situ TEM study of microplasticity and Bauschinger effect in nanocrystalline metals. Acta Mater. 58(14), 4772 (2010).Google Scholar
Xiang, Y. and Vlassak, J.J.: Bauschinger and size effects in thin-film plasticity. Acta Mater. 54(20), 5449 (2006).CrossRefGoogle Scholar
Gong, J. and Wilkinson, A.J.: Anisotropy in the plastic flow properties of single-crystal α titanium determined from micro-cantilever beams. Acta Mater. 57(19), 5693 (2009).Google Scholar
Raabe, D., Ma, D., and Roters, F.: Smaller is stronger: The effect of strain hardening. Acta Mater. 55(20), 4567 (2007).Google Scholar
Moser, G., Felber, H., Rashkova, B., Imrich, P.J., Kirchlechner, C., Grosinger, W., Motz, C., Dehm, G., and Kiener, D.: Sample preparation by metallography and focused ion beam for nanomechanical testing. Prakt. Metallogr. 49(6), 343 (2012).CrossRefGoogle Scholar
Csikor, F.F., Motz, C., Weygand, D., Zaiser, M., and Zapperi, S.: Dislocation avalanches, strain bursts, and the problem of plastic forming at the micrometer scale. Science 318(5848), 251 (2007).Google Scholar