Metallurgical Abstracts on Light Metals and Alloys vol.57
Transition of superplastic and dislocation creep of duplex Mg-Li-Al-Zn alloy
Takahiro Mineta*, Haruto Saijo*, Seita Shibata*, Seri Nakaya* and Hiroyuki Sato*
* Department of Mechanical Science and Engineering, Graduate School of Science and Technology, Hirosaki University
[Published in Materials Science and Engineering: A, Vol. 886 (2023), 145714]
https://doi.org/10.1016/j.msea.2023.145714
E-mail: mineta[at]hirosaki-u.ac.jp
Key Words: Magnesium alloys, Mg-Li based alloy, Creep, Superplasticity, Dynamic recrystallization
In this study, temperature dependence of creep behavior in a duplex Mg-Li-Al-Zn alloy was investigated. Below 473 K, creep deformation in this alloy was primarily governed by the viscous motion of dislocations. In contrast, at temperatures above 493 K, dynamic recrystallization (DRX) occurred during creep deformation, leading to a remarkable elongation exceeding 500%. Consequently, the creep behavior of the duplex Mg-Li-Al-Zn alloy exhibits a transition from viscous glide-control creep at relatively low temperatures to DRX-control superplastic creep at relatively high temperatures. These creep deformation mechanisms were elucidated through analyses based on stress exponent, activation energy of creep, and dynamic microstructural evolution.
(a–b) Creep rate-strain curves of the LAZ941 and the LZ91 alloys. (c) Creep elongation as a function of creep temperature. (d) The appearance of specimens before and after superplastic deformation.