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Solute concentration dependence of strength and plastic instabilities in Al-Mg alloys

Published online by Cambridge University Press:  03 March 2011

Gy. Horváth ,
N.Q. Chinh  and
J. Lendvai
Gy. Horváth
Affiliation:
Department of General Physics, Eötvös University, 1117 Budapest, Hungary
N.Q. Chinh*
Affiliation:
Department of General Physics, Eötvös University, 1117 Budapest, Hungary
J. Lendvai
Affiliation:
Department of General Physics, Eötvös University, 1117 Budapest, Hungary
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

Characteristics of the dynamic strain aging (DSA) in the Portevin-Le Chatelier effect are experimentally investigated by dynamic indentation tests and numerically analyzed by using literature models. Experimental results obtained on Al–Mg alloys show that the occurrence and development of the plastic instabilities—serrated indentation—depend strongly on the solute content. During dynamic microindentation tests the amplitude of microhardness drops—similarly to the global hardness—and is changing as a power law function of Mg solute content with an exponent of 2/3. It has been shown that the term describing the effect of DSA in serrated flow is not proportional but rather a power expression of the local solute concentration, Cs, on the dislocation line with the exponent of 1/2. Together with this, the kinetics of solute segregation during DSA is controlled by the pipe diffusion.

Keywords

HardnessIndentationMechanical properties
Type
Articles
Information
Journal of Materials Research , Volume 20 , Issue 2 , February 2005 , pp. 331 - 337
Copyright
Copyright © Materials Research Society 2005

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