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Electropulsing-induced phase transformations in a Zn–Al-based alloy

Published online by Cambridge University Press:  31 January 2011

Yaohua Zhu*
Affiliation:
Department of Industrial and Systems Engineering, Hong Kong Polytechnic University, Hong Kong 852, China
Wing B. Lee
Affiliation:
Department of Industrial and Systems Engineering, Hong Kong Polytechnic University, Hong Kong 852, China
Xingming Liu
Affiliation:
Hefei National Laboratory for Physical Science at Microscales, University of Science and Technology of China, Hefei, China
Guoyi Tang
Affiliation:
Graduate School at ShenZhen, Tsinghua University, Tsinghua, China
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

Microstructural changes and phase transformations of an electropulsing-treated (EPT) ZA22 alloy wire were studied using scanning electron microscopy and transmission electron-microscopy techniques. Two stages of phase transformation were detected in the EPT alloy: (i) quenching from the as furnace-cooled (FC) state to the final stable state and (ii) up-quenching from the final stable state back to the as FC state through two reverse phase transformations: T′ + η → α + ε and η′T + ε + α → η′FC. Electropulsing accelerated phase transformation tremendously. It was at least 1200 times faster than the aging process. The mechanism of the electropulsing-induced phase transformations is discussed from the point of view of Gibbs free energy and electropulsing kinetics.

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Articles
Copyright
Copyright © Materials Research Society 2009

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