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Dislocation locking versus easy glide in titanium and zirconium

Nature Materials volume 14, pages 931936 (2015) | Download Citation

Abstract

The ease of a metal to deform plastically in selected crystallographic planes depends on the core structure of its dislocations. As the latter is controlled by electronic interactions, metals with the same valence electron configuration usually exhibit a similar plastic behaviour. For this reason, titanium and zirconium, two transition metals of technological importance from the same column of the periodic table, have so far been assumed to deform in a similar fashion. However, we show here, using in situ transmission electron microscopy straining experiments, that plasticity proceeds very differently in these two metals, being intermittent in Ti and continuous in Zr. This observation is rationalized using first-principles calculations, which reveal that, in both metals, dislocations may adopt the same set of different cores that are either glissile or sessile. An inversion of stability of these cores between Zr and Ti is shown to be at the origin of the profoundly different plastic behaviours.

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Acknowledgements

This work was performed using HPC resources from GENCI-CINES, -TGCC and -IDRIS (Grant 2014-096847). The authors also acknowledge PRACE for awarding them access to the Curie resources based in France at TGCC (project PlasTitZir). They are grateful to D. Chaubet and J.-L. Béchade for processing the initial zirconium Van Arkel material. They also want to thank B. Arnal for his help in specimen preparation, and B. Legrand and F. Willaime for fruitful discussions.

Author information

Affiliations

  1. CEA, DEN, Service de Recherches de Métallurgie Physique, F-91191 Gif-sur-Yvette, France

    • Emmanuel Clouet
    •  & Nermine Chaari
  2. CEMES-CNRS, 29 rue Jeanne Marvig, BP 94347 F-31055 Toulouse Cedex, France

    • Daniel Caillard
  3. CEA, DEN, Service de Recherches Métallurgiques Appliquées, F-91191 Gif-sur-Yvette, France

    • Fabien Onimus
  4. Institut Lumière Matière, Université Lyon 1, CNRS, UMR 5306, F-69622 Villeurbanne, France

    • David Rodney

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Contributions

E.C. and N.C. performed the ab initio calculations with the help of D.R.; D.C. performed the in situ TEM straining experiments; and F.O. prepared the Zr samples for these experiments. E.C., D.C. and D.R. prepared the manuscript. All the authors discussed the results and reviewed the paper.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Emmanuel Clouet.

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DOI

https://doi.org/10.1038/nmat4340

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