TY - JOUR
T1 - Thermo-kinetic synergy and micro-alloying effects of multiphase transformations in an as-cast Al-Mg-Si-Cu alloy
AU - Jiang, Yan
AU - Li, Yunsong
AU - Liu, Feng
N1 - Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/12/10
Y1 - 2022/12/10
N2 - This work explores effects of Ge and Sb on the formation of secondary phases, with an emphasis laid on the thermo-kinetics of phase transformations and the mechanisms determining the micro-alloying effects. The results reveal that the dominating microstructures in an Al-Mg-Si-Cu alloy, including Mg2Si, Al4Cu2Mg8Si7 (Q), Si and Al2Cu (θ) phases, are thermal activated. Compared to elemental Si, intermetallic compounds like Mg2Si and Q phases have larger critical nucleation radius and phase-transformation energy barrier, and the larger thermodynamic driving force and kinetic migration energy barrier generally result in the finer microstructures. Micro-alloying affects the phase transformations in two ways: the element Sb not only promotes forming Mg3Sb2 phases but also facilitates the formation of elemental Si, Q needles and θ dispersoids through the mismatch effect; whereas the element Ge facilitates the formation of (Ge, Si) structures with different shapes and crystal structures by a substitution behavior following the formation energy criterion.
AB - This work explores effects of Ge and Sb on the formation of secondary phases, with an emphasis laid on the thermo-kinetics of phase transformations and the mechanisms determining the micro-alloying effects. The results reveal that the dominating microstructures in an Al-Mg-Si-Cu alloy, including Mg2Si, Al4Cu2Mg8Si7 (Q), Si and Al2Cu (θ) phases, are thermal activated. Compared to elemental Si, intermetallic compounds like Mg2Si and Q phases have larger critical nucleation radius and phase-transformation energy barrier, and the larger thermodynamic driving force and kinetic migration energy barrier generally result in the finer microstructures. Micro-alloying affects the phase transformations in two ways: the element Sb not only promotes forming Mg3Sb2 phases but also facilitates the formation of elemental Si, Q needles and θ dispersoids through the mismatch effect; whereas the element Ge facilitates the formation of (Ge, Si) structures with different shapes and crystal structures by a substitution behavior following the formation energy criterion.
KW - Al-Mg-Si-Cu alloy
KW - Micro-alloying
KW - Multiphase transformation
KW - Thermo-kinetics
UR - http://www.scopus.com/inward/record.url?scp=85138539032&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2022.166784
DO - 10.1016/j.jallcom.2022.166784
M3 - 文章
AN - SCOPUS:85138539032
SN - 0925-8388
VL - 926
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
M1 - 166784
ER -