Rev.Adv.Mater.Sci. (RAMS)
No 7, Vol. 18, 2008, pages 583-589

MECHANICAL AND ACOUSTIC EMISSION BEHAVIOUR INDUCED BY CHANNEL-DIE
COMPRESSION OF Mg-Li NANOCRYSTALLINE ALLOYS OBTAINED BY ECAP TECHNIQUE

J. Kuśnierz, A. Pawełek, Z. Ranachowski, A. Piątkowski, Z. Jasieński,
S. Kúdela and S. Kúdela, Jr.

Abstract

In the paper there are presented the results of investigations of the relations between the plastic strain mechanisms and the acoustic emission (AE) induced channel-die compression of magnesium and Mg8Li and Mg12Li alloys of ultra fine-grained (UFG) (nanocrystalline) structure, obtained using the technique of equal channel angular pressing (ECAP). The results are compared with those obtained for similar materials not subjected to ECAP operation. Moreover, the results obtained using of a new generation AE analyser are compared with those obtained earlier using an AE analyser of older generation. The spectral analysis of the detected AE signals has been carried out and the AE behaviour discussed in the context of both the dislocation strain and the superplastic flow mechanisms in UFG materials.

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