TY - JOUR
T1 - Recovery features of kink boundaries upon post-annealing of a hot-extruded Mg-Zn-Y alloy
AU - Egusa, Daisuke
AU - Inoue, Koji
AU - Nagai, Yasuyoshi
AU - Abe, Eiji
N1 - Funding Information:
This work was supported by JSPS KAKENHI for Scientific Research on Innovative Areas “Materials Science of a Mille-feuille Structure (Grant Numbers JP18H05475 , JP18H05479 )”, and “Nanotechnology Platform” of the MEXT , Japan.
Publisher Copyright:
© 2021 Elsevier Inc.
PY - 2021/7
Y1 - 2021/7
N2 - We have investigated a post-annealing effect on microscopic structural changes of kink boundaries (KBs), which have been initially introduced by a hot-extrusion of an Mg-Zn-Y alloy containing long period stacking/order (LPSO) phase, based on scanning transmission electron microscopy (STEM) and atom-probe tomography (APT). STEM observations show that most of the KBs appear to be segmented into several submicron-scale, each of which is composed of arrays of extended basal (a-) dislocations that are geometrically necessary to account for the LPSO crystalline rotations. Atomic-scale STEM/APT observations reveal significant reconstructions of these extended dislocation-core structures, which occur at the solute-enriched face-centered cubic layers in the LPSO structures and forms local hexagonal close-packed Mg region with distinct solute depletions. These recovery-like features indeed enhance the thermal stability of the KBs, and the corresponding driving force can be reasonably described according to disclinations, whose elastic energy is defined by crystal rotations and the relevant dipole distances.
AB - We have investigated a post-annealing effect on microscopic structural changes of kink boundaries (KBs), which have been initially introduced by a hot-extrusion of an Mg-Zn-Y alloy containing long period stacking/order (LPSO) phase, based on scanning transmission electron microscopy (STEM) and atom-probe tomography (APT). STEM observations show that most of the KBs appear to be segmented into several submicron-scale, each of which is composed of arrays of extended basal (a-) dislocations that are geometrically necessary to account for the LPSO crystalline rotations. Atomic-scale STEM/APT observations reveal significant reconstructions of these extended dislocation-core structures, which occur at the solute-enriched face-centered cubic layers in the LPSO structures and forms local hexagonal close-packed Mg region with distinct solute depletions. These recovery-like features indeed enhance the thermal stability of the KBs, and the corresponding driving force can be reasonably described according to disclinations, whose elastic energy is defined by crystal rotations and the relevant dipole distances.
KW - Atom probe tomography (APT)
KW - Kink deformation
KW - Long-period stacking/order phase (LPSO)
KW - Magnesium alloys
KW - Scanning transmission electron microscopy (STEM)
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U2 - 10.1016/j.matchar.2021.111153
DO - 10.1016/j.matchar.2021.111153
M3 - Article
AN - SCOPUS:85105047135
VL - 177
JO - Materials Characterization
JF - Materials Characterization
SN - 1044-5803
M1 - 111153
ER -