Metallurgical Abstracts on Light Metals and Alloys vol.56
Dislocation Analysis in Mg2Ca Lamella of Crept α-Mg/C14–Mg2Ca Eutectic Alloy
Hiromu Hisazawa*, Koji Oishi** and Yoshihiro Terada**
* Graduate School of Technology, Industrial and Social Sciences, Tokushima University
** Department of Materials Science and Engineering, Tokyo Institute of Technology
[Published in Journal of the Society of Materials Science, Japan, Vol. 72 (2023), pp. 121–123]
https://www.jstage.jst.go.jp/article/jsms/72/2/72_121/_article/-char/en
E-mail: terada.y.ab[at]m.titech.ac.jp
Key Words: Magnesium alloy, C14–Mg2Ca, Lamellar, Dislocation, Burgers vector
The dislocations introduced during creep in the hard C14–Mg2Ca lamellae for the α-Mg/C14–Mg2Ca eutectic alloy were analyzed using high-resolution transmission electron microscopy. The isolated dislocations are introduced into C14 lamellae from the stress-concentrated α/C14 interface during creep and identified as a dislocation with the Burgers vector of 1/3[1120], supposing that all dislocations in the Mg2Ca phase split into partial dislocations. The introduced perfect dislocation is an a dislocation on the basal plane, which can dissociate into partial dislocations by the following reaction during creep; 1/3[1120] → 1/3[1010] ＋ SF(0001) ＋ 1/3[0110].
Figure HRTEM images, taken with B=[1213]C14, of the α-Mg/C14–Mg2Ca eutectic alloy creep- ruptured at 473 K under a stress of 40 MPa. The dislocations are visible within the C14–Mg2Ca lamella in (a) and (b) as shown by white arrowheads, while they are not observable in (c). The dislocation alignment is detected within the α-Mg lamella as shown by an arrowhead in (c).