Vacancy and solute co-segregated η1 interface in over-aged Al-Zn-Mg alloys
Source abstract
Abstract
Abstract We present a combined first-principles and scanning transmission electron microscopy (STEM) study of the η1/Al interfaces in an over-aged Al-Zn-Mg alloy. As one of the major η-MgZn2 precipitate types, η1 tends to form highly coherent interfaces with Al matrix, along with various solute segregation patterns on its interfacial layers. The interface phase diagram suggests either an Mg-rich or a Zn-rich interface, depending on the chemical potential range of Zn. Further segregation calculations, however, strongly suggest the STEM Z-contrast imaged interface to be a vacancy and solute co-stabilized Mg-rich structure that is favored at relatively low Zn chemical potentials. Based on our experimental and calculation results, the profound thermodynamics origin of the η1/Al interface and its intricate segregation behavior is clarified and described using a generalized structure model. The η1/Al interface structure and segregation at higher Zn chemical potentials are also predicted for future experimental validation.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Aluminum Alloy Microstructure Properties · Aluminum Alloys Composites Properties · Magnesium Alloys: Properties and Applications
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (45)
Show source-provided references
1. Progress in structural materials for aerospace systems10.1016/j.actamat.2003.08.023 ↗
2. Recent developments in advanced aircraft aluminium alloys10.1016/j.matdes.2013.12.002 ↗
3. An electron microscope investigation of the microstructure in an aluminium-zinc-magnesium alloy10.1016/0001-6160(70)90016-7 ↗
4. Microstructural evolution and age hardening in aluminium alloys: atom probe field-ion microscopy and transmission electron micro-scopy studies10.1016/S1044-5803(99)00051-0 ↗
5. Precipitates in aluminium alloys
6. GP-zones in Al-Zn-Mg alloys and their role in artificial aging10.1016/S1359-6454(01)00251-8 ↗
7. Early-stage precipitation in Al-Zn-Mg-Cu alloy (7050)10.1016/j.actamat.2004.06.025 ↗
8. Characterization of precipitation microstructure and properties of 7150 aluminium alloy10.1016/j.msea.2006.04.043 ↗
9. Microstructure and mechanical properties of a large billet of spray formed Al-Zn-Mg-Cu alloy with high Zn content10.1016/j.msea.2008.12.010 ↗
10. Stress corrosion cracking behaviour of 7xxx aluminum alloys: A literature review10.1016/S1003-6326(16)64220-6 ↗
11. Stress corrosion cracking in an extruded Cu-free Al-Zn-Mg Alloy10.3390/met10091194 ↗
12. Precipitation in an extruded AA7003 aluminium alloy: Observations of 6xxx-type hardening phases10.1016/j.matdes.2019.108204 ↗
13. The crystal structure of magnesium di-zincide10.1103/PhysRev.29.34 ↗
14. Structural studies of stacking variants in Mg-base Friauf-Laves phases10.1107/S0567740880006565 ↗
15. Transmission electron microscopy investigation of separated nucleation and in-situ nucleation in AA7050 aluminium alloy10.1016/j.actamat.2018.02.045 ↗
16. An atomic scale structural investigation of nanometre-sized η precipitates in the 7050 aluminium alloy10.1016/j.actamat.2019.05.041 ↗
17. Precipitation sequences during quenching of the AA 7010 alloy10.1016/S1359-6454(02)00063-0 ↗
18. An unreported precipitate orientation relationship in Al-Zn-Mg based alloys10.1016/j.matchar.2019.109958 ↗
19. Influence of equal-channel angular pressing on precipitation in an Al-Zn-Mg-Cu alloy10.1016/j.actamat.2009.03.017 ↗
20. A structural investigation of multiple aging of Al-7 wt pct Zn-2.3 wt pct Mg10.1007/BF02669384 ↗
21. Precipitates, zones and transitions during aging of Al-Zn-Mg-Zr 7000 series alloy10.1179/026708304225010424 ↗
22. The effect of certain trace element additions on the ageing behavior of an aluminum-4 wt% Zinc-3 wt% magnesium alloy
23. Precipitation kinetics in an Al-Zn-Mg-alloy
24. Atomic scale HAADF-STEM study of η′ and η1 phases in peak-aged Al-Zn-Mg alloys10.1007/s10853-017-1873-0 ↗
25. Characterisation of structural similarities of precipitates in Mg–Zn and Al–Zn–Mg alloys systems10.1080/14786435.2019.1637032 ↗
26. Atomic structure of hardening precipitates in an Al-Mg-Zn-Cu alloy determined by HAADF-STEM and first-principles calculations: relation to η-MgZn210.1007/s10853-013-7158-3 ↗
27. Experimental and DFT characterization of η′ nano-phase and its interfaces in Al-Zn-Mg-Cu alloys10.1016/j.actamat.2018.10.045 ↗
28. Co-segregation of Mg and Zn atoms at the planar η1-precipitate/Al matrix interface in an aged Al-Zn-Mg alloy10.1016/j.scriptamat.2020.04.004 ↗
29. Smart Align—a new tool for robust non-rigid registration of scanning microscope data10.1186/s40679-015-0008-4 ↗
30. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set10.1103/PhysRevB.54.11169 ↗
31. Projector augmented-wave method10.1103/PhysRevB.50.17953 ↗
32. From ultra-soft pseudo-potentials to the projector augmented wave method10.1103/PhysRevB.59.1758 ↗
33. Universal features of the equation of state of solids10.1088/0953-8984/1/11/002 ↗
34. Ground State of the Electron Gas by a Stochastic Method10.1103/PhysRevLett.45.566 ↗
35. Self-interaction correction to density-functional approximations for many-electron systems10.1103/PhysRevB.23.5048 ↗
36. Simmons · 1971
37. Generalized gradient approximation made simple10.1103/PhysRevLett.77.3865 ↗
38. Z dependence of electron scattering by single atoms into annular dark-field detectors10.1017/S1431927611012074 ↗
39. Microstructure-lattice thermal conductivity correlation in nanostructured PbTe0.7S0.3thermoelectric materials10.1002/adfm.200901905 ↗
40. Formation of coherent, core-shelled nano-particles in dilute Al-Sc-Zr alloys from the first-principles10.1016/j.jmst.2018.11.004 ↗
41. First-principles study of hydrogen segregation at the MgZn2 precipitate in Al-Mg-Zn alloys10.1016/j.commatsci.2018.03.009 ↗
42. The ferrite/oxide interface and helium management in nano-structured ferritic alloys from the first principles10.1016/j.actamat.2015.10.031 ↗
43. Adhesion of the γ-Ni (Al)/α-Al2O3 interface: a first-principles assessment10.3139/146.101592 ↗
44. First principles assessment of metal/oxide interface adhesion10.1063/1.2907339 ↗
45. First-principles calculation of interaction energies between solutes and/or vacancies for predicting atomistic behaviors of microalloying elements in aluminum alloys10.4028/www.scientific.net/MSF.561-565.283 ↗