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In situ study of thermally activated flow and dynamic restoration of ultrafine-grained pure Cu at 373 K

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Abstract

Pure Cu was made ultrafine-grained by equal channel angular pressing on route BC at ambient temperatures and deformed in situ in a scanning electron microscope at the elevated temperature of 373 K and at a constant total strain rate of 10−4 s−1. Deformation was repetitively stopped to take micrographs of the grain structure on the same area of observation, revealing limited activity of discontinuous dynamic recrystallization. During the stops of deformation, the flow stress was relaxing. The relaxation of stress as function of time was used to determine the rate of inelastic deformation as a function of stress, from which the activation volume V* of the thermally activated flow was derived. It is found that the normalized values of V* were lying in the same order generally found for coarse-grained pure materials. This seems to be in conflict with the literature. However, the conflict is resolved by noting that the literature results refer to quasistationary deformation with the concurrent dynamic recovery in contrast to the present results obtained at a virtually constant microstructure. The interpretation of the two kinds of activation volumes for thermally activated flow is discussed.

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References

  1. R.Z. Valiev, R.K. Islamgaliev, and I.V. Alexandrov: Bulk nanostructured materials from severe plastic deformation. Prog. Mater. Sci. 45, 103 (2000).

    Article  CAS  Google Scholar 

  2. H.W. Höppel, M. Brunnbauer, H. Mughrabi, R.Z. Valiev, and A.P. Zhilyaev: Cyclic deformation behaviour of ultrafine grain size copper produced by equal channel angular extrusion. In Materials Week 2000-Proceedings (Werkstoffwoche-Partnerschaft GbR, Frankfurt, 2001); p. 1.

    Google Scholar 

  3. H.W. Höppel, Z.M. Zhou, H. Mughrabi, and R.Z. Valiev: Microstructural study of the parameters governing coarsening and cyclic softening in fa-tigued ultrafine-grained copper. Philos. Mag. A 9, 1781 (2002).

    Article  Google Scholar 

  4. X. Molodova, G. Gottstein, M. Winning, and R.J. Hellmig: Thermal stability of ECAP processed pure copper. Mater. Sci. Eng., A 460–461, 204 (2007).

    Article  Google Scholar 

  5. W. Blum, Y.J. Li, and K. Durst: Stability of ultrafine-grained Cu to subgrain coarsening and recrystallization in annealing and deformation at elevated temperatures. Acta Mater. 57, 5207 (2009).

    Article  CAS  Google Scholar 

  6. K.V. Ivanov and E.V. Naydenkin: Activation parameters and deformation mechanisms of ultrafine-grained copper under tension at moderate temperatures. Mater. Sci. Eng., A 608, 123 (2014).

    Article  CAS  Google Scholar 

  7. W. Blum, J. Dvorak, P. Kral, M. Petrenec, P. Eisenlohr, and V. Sklenicka: In situ study of structure and strength of severely predeformed pure Cu in deformation at 573 K. Philos. Mag. 95 (33), 3696 (2015).

    Article  CAS  Google Scholar 

  8. H.J. Frost and M.F. Ashby: Deformation-Mechanism Maps (Pergamon Press, Oxford, 1982); p. 166.

    Google Scholar 

  9. M. Petrenec, P. Kral, J. Dvorak, M. Svoboda, and V. Sklenicka: In situ testing and heterogeneity of UFG Cu at elevated temperatures. J. Achiev. Mater. Manuf. Eng. 62 (2), 69 (2014).

    Google Scholar 

  10. W. Blum, Y.J. Li, Y. Zhang, and J.T. Wang: Deformation resistance in the transition from coarse-grained to ultrafine-grained Cu by severe plastic deformation up to 24 passes of ECAP. Mater. Sci. Eng., A 528, 8621 (2011).

    Article  CAS  Google Scholar 

  11. W. Blum: High-temperature deformation and creep of crystalline solids. In Plastic Deformation and Fracture of Materials, H. Mughrabi, ed.; Materials Science and Technology, Vol. 6 of series Materials Science and Technology, R.W. Cahn, P. Haasen, and E.J. Kramer, eds. (VCH Verlagsgesellschaft, Weinheim, 1993); p. 359.

    Google Scholar 

  12. Y.J. Li, J. Mueller, H.W. Höppel, M. Göken, and W. Blum: Deformation kinetics of nanocrystalline nickel. Acta Mater. 55, 5708 (2007).

    Article  CAS  Google Scholar 

  13. Y.J. Li, X.H. Zeng, and W. Blum: Transition from strengthening to softening by grain boundaries in ultrafine-grained Cu. Acta Mater. 52 (17), 5009 (2004).

    Article  CAS  Google Scholar 

  14. E. Nes: Modelling work hardening and stress saturation in FCC metals. Prog. Mater. Sci. 41 (3), 129 (1998).

    Article  Google Scholar 

  15. H. Mecking, B. Nicklas, N. Zarubova, and U.F. Kocks: An “universal” temperature scale for plastic flow. Acta Metall. 34, 527 (1986).

    Article  Google Scholar 

  16. U.F. Kocks: Proceedings of the Conference at the 50th Anniversary Meeting on Dislocations and Properties of Real Materials (The Institute of Metals, London, 1985); p. 125.

    Google Scholar 

  17. U.F. Kocks and H. Mecking: Physics and phenomenology of strain hardening: The FCC case. Prog. Mater. Sci. 48 (3), 171 (2003).

    Article  CAS  Google Scholar 

  18. A.K. Mukherjee, J.E. Bird, and J.E. Dorn: Experimental correlations for high-temperature creep, ASM Trans. Q. 62 (155) (1969).

  19. J. Cadek: Creep in Metallic Materials (Elsevier, Amsterdam, 1988); p. 270.

    Google Scholar 

  20. M. Kassner and M.T. Perez-Prado: Fundamentals of Creep in Metals and Alloys (Elsevier, Amsterdam, 2004); p. 338.

    Google Scholar 

  21. D. Caillard: A model of creep at intermediate temperatures in aluminium. Philos. Mag. A 51 (1), 157 (1985).

    Article  CAS  Google Scholar 

  22. D. Caillard and J.L. Martin: New trends in creep microstructural models for pure metals. Rev. Phys. Appl. 22, 169 (1987).

    Article  CAS  Google Scholar 

  23. W. Blum, A. Rosen, A. Cegielska, and J.L. Martin: Two mechanisms of dislocation motion during creep. Acta Metall. 37, 2439 (1989).

    Article  CAS  Google Scholar 

  24. Z. Sun, S. Van Petegem, A. Cervellino, K. Durst, W. Blum, and H. Van Swygenhoven: Dynamic recovery in nanocrystalline Ni. Acta Mater. 91, 91 (2015).

    Article  CAS  Google Scholar 

  25. R.W. Armstrong: Thermal activation strain rate analysis (TASRA) for polycrystalline materials, (Indian) J. Sci. Indust. Res. 32, 591 (1973).

    CAS  Google Scholar 

  26. R.W. Armstrong and N. Balasubramanian: Physically-based and power-law constitutive relations for higher temperature metal processing and creep-type deformations. J. Met. 69 (5), 822 (2017).

    Google Scholar 

  27. C. Duhamel, Y. Brechet, and Y. Champion: Activation volume and deviation from Cottrell–Stokes law at small grain size. Int. J. Plast. 26, 747 (2010).

    Article  CAS  Google Scholar 

  28. R.W. Armstrong: Comparison of grain size and strain rate influences on higher temperature metal strength and fracturing properties. In David M.R. Taplin Symposium, Proc. 14th International Conference on Fracture (ICF14) (Rhodes, Greece, 2017).

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ACKNOWLEDGMENTS

This research has been financially supported by the Ministry of Education, Youth and Sports of the Czech Republic under the project CEITEC 2020 (LQ1601). Stimulating discussions with Prof. Ron Armstrong are gratefully acknowledged.

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Authors and Affiliations

  1. Institut für Werkstoffwissenschaften, University of Erlangen-Nürnberg, Erlangen, D-91058, Germany

    Wolfgang Blum

  2. Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Brno, CZ-61662, Czech Republic

    Petr Král, Jiri Dvořák & Vaclav Sklenička

  3. Tescan Orsay Holding a.s., Brno, CZ-62300, Czech Republic

    Martin Petrenec

  4. Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan, 48824, USA

    Philip Eisenlohr

Authors
  1. Wolfgang Blum
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  2. Petr Král
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  3. Jiri Dvořák
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  4. Martin Petrenec
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  5. Philip Eisenlohr
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  6. Vaclav Sklenička
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Correspondence to Wolfgang Blum.

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Dedicated to Prof. Hael Mughrabi on the occasion of his 80th birthday.

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Blum, W., Král, P., Dvořák, J. et al. In situ study of thermally activated flow and dynamic restoration of ultrafine-grained pure Cu at 373 K. Journal of Materials Research 32, 4514–4521 (2017). https://doi.org/10.1557/jmr.2017.343

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  • DOI: https://doi.org/10.1557/jmr.2017.343

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