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

  • M.W. Kapp (a1), C. Kirchlechner (a2), R. Pippan (a3) and G. Dehm (a4)

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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a) Address all correspondence to this author. e-mail: kirchlechner@mpie.de

References

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1. 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).
2. 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).
3. 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).
4. 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).
5. 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).
6. Kraft, O., Gruber, P.A., Mönig, R., and Weygand, D.: Plasticity in confined dimensions. Annu. Rev. Mater. Res. 40, 293 (2010).
7. 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).
8. 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).
9. Stölken, J.S. and Evans, A.G.: A microbend test method for measuring the plasticity length scale. Acta Mater. 46(14), 5109 (1998).
10. 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).
11. 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).
12. Volkert, C.A. and Lilleodden, E.T.: Size effects in the deformation of sub-micron Au columns. Philos. Mag. 86(33–35), 5567 (2006).
13. 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).
14. 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).
15. 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).
16. Suresh, S.: Fatigue of Materials (Cambridge University Press, Cambridge, 1998).
17. Pedersen, O.B., Brown, L.M., and Stobbs, W.M.: The Bauschinger effect in copper. Acta Metall. 29(11), 1843 (1981).
18. 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).
19. Xiang, Y. and Vlassak, J.J.: Bauschinger and size effects in thin-film plasticity. Acta Mater. 54(20), 5449 (2006).
20. 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).
21. Raabe, D., Ma, D., and Roters, F.: Smaller is stronger: The effect of strain hardening. Acta Mater. 55(20), 4567 (2007).
22. 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).
23. 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).

Keywords

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

  • M.W. Kapp (a1), C. Kirchlechner (a2), R. Pippan (a3) and G. Dehm (a4)

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