Hostname: page-component-848d4c4894-v5vhk Total loading time: 0 Render date: 2024-07-03T05:09:43.279Z Has data issue: false hasContentIssue false
  • English
  • Français

Mechanical Behaviour of Nanocrystalline Copper Related to Grain-boundary Structure

Published online by Cambridge University Press:  01 February 2011

Y. Champion ,
P. Langlois ,
S. Guérin-Mailly ,
C. Langlois  and
M. J. Hÿtch
Y. Champion
Affiliation:
Centre d'Etude de Chimie Métallurgique – CNRS, 15 rue Georges Urbain 94407 Vitry-sur-Seine, France
P. Langlois
Affiliation:
LIMHP-CNRS, Université Paris XIII, 99 av. J.B Clément, 93430 Villetaneuse, France.
S. Guérin-Mailly
Affiliation:
Centre d'Etude de Chimie Métallurgique – CNRS, 15 rue Georges Urbain 94407 Vitry-sur-Seine, France
C. Langlois
Affiliation:
Centre d'Etude de Chimie Métallurgique – CNRS, 15 rue Georges Urbain 94407 Vitry-sur-Seine, France
M. J. Hÿtch
Affiliation:
Centre d'Etude de Chimie Métallurgique – CNRS, 15 rue Georges Urbain 94407 Vitry-sur-Seine, France
Get access

Abstract

Understanding the mechanical behaviour of metallic nanostructures is a key issue for their development. On the one hand, knowledge of the plastic behaviour at various temperatures is essential to control the synthesis, forming, and machining of such materials. Equally, a clear understanding of atomic and mesoscopic mechanisms, involving defects and their interactions, is essential for the control of ageing and functional properties. Regarding plastic deformation at room temperature, there is now evidence for unusual behaviour in nanostructured metals. In addition to high resistance and ductility, tensile testing reveals peculiar elasto-plastic deformation. Such behaviour was initially attributed to grain-boundary sliding. However, intergranular areas (including triple junctions) may possess special properties compared to their microcrystalline counterparts. For example, low activation energies have been measured for grain-boundary diffusion and it has been observed that grain-boundaries may act as dislocation sources and nucleation sites for deformation twinning.

In this paper, we report on analysis on bulk copper nanostructures. Grain-boundaries are studied, by cross-correlating information from mechanical tensile testing and structural analysis, including X-ray diffraction (XRD) and transmission electron microscopy (TEM). Macroscopic bulk specimens (with grain size of about 80 nm) are prepared by powder metallurgy techniques, modified to fit to the special properties of nanocrystalline powders. Processing includes coldisostatic pressing, sintering and differential extrusion. The powders used (grain size of 40 nm) are synthesised by evaporation and cryo-condensation of a metallic vapour within liquid nitrogen. Results on mechanical testing and structural analysis will be reported. Emphasis will be placed on the structure of grain-boundaries (type of grain-boundary, grain-boundary thickness) studied by TEM and high resolution TEM image analysed using the geometric phase technique. The nanostructure was revealed to be consist in agglomerate of nano-size grains separated by low angle grain-boundaries. Agglomerates are themselves separerated by general high angle boundaries. These observations will then be related to the unusual mechanical true stress-true strain curves of the metallic nanostructures.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 727: Symposium R – Nanostructured Interfaces , 2002 , R3.2
Copyright
Copyright © Materials Research Society 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Karch, J., Birringer, R. and Gleiter, H., Nature, 330, 556–558 (1987).Google Scholar
2. McFadden, S.X., Mishra, R.S., Valiev, R.Z., Zhilyaev, A.P., Mukherjee, A.K., Nature 398, 684, (1999).Google Scholar
3. Champion, Y., Guérin-Mailly, S., Bonnentien, J.L., Langlois, P., Scripta Mater. 44, 1609, (2001).Google Scholar
4. Arzt, E. Acta Mater. 46, 5611–5626 (1998).Google Scholar
5. Cottrell, A. H., “Dislocations and plastic flow in crystals” (Oxford University press, 1953)Google Scholar
6. Champion, Y. and Bigot, J., Scripta Materialia 35, 517, (1996).Google Scholar
7. Nieh, T.G. and Wadsworth, J.. Scripta Metall. 25, 955–958 (1991)Google Scholar
8. Dominguez, O., Champion, Y. and Bigot, J., Metallurgical and Materials Transactions A 29A, 2941–2949 (1998).Google Scholar
9. Champion, Yannick, Bernard, Frédéric, Guigue-Millot, Nadine and Perriat, Pascal, (in preparation).Google Scholar
10. Young, W. S. and Cutler, I. B., Journal of American Ceramamic Society 53, 659, (1970).Google Scholar
11. Johnson, D. L., Journal of Applied Physics 40, 192, (1969).Google Scholar
12. Horvath, J., Birringer, R., and, Gleiter, H., Solid state communications, 62, 319, (1987).Google Scholar
13. , Zhu and , Averback, Phil. Mag. Lett., 73, 27, (1995).Google Scholar
14. German, R. M., “Sintering theory and practice”. (John Willey and Son Inc, New York, 1996).Google Scholar
15. Hÿtch, M.J., Snoeck, E., Kilaas, R., Ultramicroscopy 74, 131, (1998).Google Scholar
16. Hÿtch, M.J., in Stress and Strain in Epitaxy: theoretical concepts, measurements and applications. Editors Margrit Hanbücken, Jean-Paul Deville (Elsevier, Amsterdam, 2001) pp 201–219.Google Scholar
17. Hÿtch, M. J. and Plamann, T., Ultramicroscopy 87, 199, (2001).Google Scholar
18. Treacy, M.M.J., Gibson, J.M., Howie, A., Phil. Mag. A 51, 389, (1985).Google Scholar
19. Champion, Y. and Hytch, M.J., European Physical Journal: Applied Physics 4, 161, (1998).Google Scholar