Dislocation Plasticity and Complementary Deformation Mechanisms in Polycrystalline Mg Alloys

Article Preview

Abstract:

Deformation mechanisms of Mg-Al-Zn (AZ31) alloys were investigated by performing tensile test at room temperature. In fine grain Mg alloys deformed at room temperature, nonbasal slip systems were found to be active as well as basal slip systems because of grain-boundary compatibility effect. Slip-induced grain-boundary sliding occurred as a complementary deformation mechanism to give rise to c-axis component of strain. With increasing grain size, the activation of the nonbasal slip systems was limited near grain boundaries. Instead of grain-boundary sliding, twinning occurred as a complementary deformation mechanism in large grained samples. Orientation analysis of twins indicated that twinning is induced by stress concentration due to the pile up of basal dislocations. The grain-size dependence on deformation mechanism was found to affect yielding behavior both microscopically and macroscopically which can influence various mechanical properties such as fatigue and creep.

You might also be interested in these eBooks

Info:

Periodical:

Materials Science Forum (Volumes 449-452)

Pages:

665-668

Citation:

Online since:

March 2004

Authors:

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2004 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

[1] See for example, Magnesium Alloys 2003, Ed. by Y. Kojima, T. Aizawa, K. Higashi and S. Kamado, (Trans Tech Publications, Switzerland, 2003).

Google Scholar

[2] W. F. Sheerly and R. R. Nash: Trans. Metall. Soc. AIME, Vol. 218 (1960) p.416.

Google Scholar

[3] T. Obara, H. Yoshinaga and S. Morozumi: Acta Metall. Vol. 21 (1973) p.845.

Google Scholar

[4] H. Yoshinaga and R. Horiuchi: Trans JIM Vol. 5 (1963) p.14.

Google Scholar

[5] J. F. Stohr and J. P. Pirier, Philos. Mag. Vol. 25 (1972) p.1313.

Google Scholar

[6] J. Koike, T. Kobayashi, T. Mukai, H. Watanabe, M. Suzuki, K. Maruyama and K. Higashi: Acta Mater. Vol. 51 (2003) p. (2055).

Google Scholar

[7] J. Koike, R. Ohyama, T. Kobayashi, M. Suzuki and K. Maruyama: Mater. Trans. Vol. 44 (2003) p.445.

Google Scholar

[8] J. Koike, T. Kobayashi, Y. Yoshida, S. Kamado, M. Suzuki K. Maruyama and K. Kojima, to be published. ���� ������������ ���� ������������ ���� ���� �������� �������� �������� ����total /10-2 ǭǭǭǭGBS / 10-2 080. total GBS = ǭǭǭǭ ǭǭǭǭ RT Fig. 5 GBS strain as a function of total strain. Journal Title and Volume Number (to be inserted by the publisher).

Google Scholar

[9] M. H. Yoo: Metall. Trans. A Vol. 12A (1981) p.409.

Google Scholar