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Grain refinement of Mg–10Gd alloy by Al additions

Published online by Cambridge University Press:  01 October 2012

Jichun Dai ,
Mark Easton ,
Suming Zhu ,
Guohua Wu  and
Wenjiang Ding
Jichun Dai
Affiliation:
School of Materials Science and Engineering, National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shanghai 200240, China; and Department of Materials Engineering, CAST Cooperative Research Centre, Monash University, Victoria 3800, Australia
Mark Easton
Affiliation:
Department of Materials Engineering, CAST Cooperative Research Centre, Monash University, Victoria 3800, Australia
Suming Zhu
Affiliation:
Department of Materials Engineering, CAST Cooperative Research Centre, Monash University, Victoria 3800, Australia
Guohua Wu*
Affiliation:
School of Materials Science and Engineering, National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shanghai 200240, China; and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China
Wenjiang Ding
Affiliation:
School of Materials Science and Engineering, National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shanghai 200240, China; and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China
*
a)Address all correspondence to this author. e-mail: ghwu@sjtu.edu.cn
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Abstract

The addition of Al to a Mg–10Gd alloy was found to lead to substantial grain size reduction during casting at concentrations between 0.8% and 1.3%. At these concentrations, Al2Gd particles were found at the center of grains, and the orientation relationship $[112]_{{\rm{Al}}_{\rm{2}} {\rm{Gd}}} \,{\rm{‖}}\,[2\bar 1\bar 10]_{{\rm{\alpha - Mg}}} ,\,(1\bar 10)_{{\rm{Al}}_{\rm{2}} {\rm{Gd}}} \,{\rm{‖}}\,(0\bar 110)_{{\rm{\alpha - Mg}}} $ was found reproducibly between Al2Gd and α-Mg, indicating that these are the heterogeneous nucleant particles that form in situ at these Al contents. Most of these nuclei were between 2 and 7 μm in size. Furthermore, little grain coarsening was observed during solution treatment, particularly compared with an alloy grain refined by Zr particles where substantial coarsening occurred. This appears to be because Al2Gd particles restrict grain boundary motion during solution treatment.

Type
Articles
Information
Journal of Materials Research , Volume 27 , Issue 21 , 14 November 2012 , pp. 2790 - 2797
Copyright
Copyright © Materials Research Society 2012

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