Materials Transactions Online

Materials Transactions, Vol.44 No.6 (2003) pp.1198-1203
© 2003 The Japan Institute of Metals
EXPRESS REGULAR ARTICLE

Capacity for Deformation and the Evaluation of Flow Stress of Hot Extruded Mg-8Al-xRE Alloys at Elevated Temperatures

Wan-Gye Yang* and Chun-Hao Koo**

Department of Materials Science and Engineering, National Taiwan University, Taipei, 106 Taiwan, R.O. China

This paper investigated the optimal deformation temperature Tc, and the optimal Zener-Hollomon parameter Zc, of both as-extruded Mg-8Al and Mg-8Al-2RE alloys, to examine the capacity of these alloys for deformation. Additionally, an equation that involves the Zener-Hollomon parameter Z was derived to evaluate the flow stress of these magnesium alloys at various temperatures and strain rates and was validated using a statistical method. These alloys were prepared by melting and casting in a vacuum induction furnace, and extruded at 633 K with a reduction ratio of 90:1. Tensile tests were performed at 473 to 723 K and at strain rates ranging from 8.3× 10-4 to 8.3× 10-1 s-1. The implications of the experimental data were discussed in detail.

(Received February 24, 2003; Accepted May 6, 2003)

Keywords: magnesium alloys, rare-earth element, extrusion, mechanical properties, hot working, Zener-Hollomon parameter


*Graduate Student, National Taiwan University.
**Corresponding author: E-mail: chkoo@ccms.ntu.edu.tw

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