journal article·2021-06Open access

Atomic structures of interfacial solute gateways to θ′ precipitates in Al-Cu alloys

M.F. Chisholm, D. Shin, G. Duscher, M.P. Oxley, L.F. Allard, J.D. Poplawsky, A. Shyam

Acta Materialia· Volume 212

Abstract

Abstract Many materials employed in critical structural applications depend upon metastable strengthening precipitates that transform or dissolve at elevated temperatures. Herein, aberration-corrected scanning transmission electron microscopy and first-principles calculations are used to accurately determine the atomic structure of the highly mobile, semi-coherent precipitate interfaces that control this process in the classic θ′ (Al2Cu) precipitate in the Al-Cu system. Semi-coherent {110} interfaces are found to be composed of an array of unexpected misfit dislocations that are arranged in two different structural units. Dislocations accommodate nearly all of the misfit between the Al matrix and strengthening phase. Cu is observed to segregate to the compressed edge of the dislocation cores at specific sites in this interface. First-principles calculations revealed the energetic landscape that facilitates these sites to become entry and exit gateways of Cu atoms in this semi-coherent interface. This investigation reveals critical features within semi-coherent interfaces that determine the thermal stability of precipitation-hardened alloys.
Source: openaire · Quality: candidate unverified · Source record ↗

Research context

OpenAlex topics: Aluminum Alloy Microstructure Properties · Aluminum Alloys Composites Properties · Microstructure and mechanical properties

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (39)

Show source-provided references
1. Precipitation hardening: from Alfred Wilm to present
2. Physical metallurgical experiments on aluminum alloys containing magnesium
3. A. Wilm, Kaiserliches Patentamt 244554 (1909).
4. Structure of age-hardened aluminium-copper alloys10.1038/142569b0 ↗
5. The diffraction of X-rays by age-hardening aluminium copper alloys10.1098/rspa.1938.0152 ↗
6. Structural ageing characteristics of binary aluminium-copper alloys
7. Microstructural design of high-strength aluminum alloys10.1361/105497198770341734 ↗
8. Strengthening of an Al–Cu–Sn alloy by deformation-resistant precipitate plates10.1016/j.actamat.2008.03.028 ↗
9. On the strengthening response of aluminum alloys containing shear-resistant plate-shaped precipitates10.1016/j.actamat.2008.08.023 ↗
10. Physical Metallurgy of Light Alloys
11. Microstructural evolution and deformation behavior of Al-Cu alloys: a transmission X-ray microscopy (TXM) and micropillar compression study10.1016/j.actamat.2017.11.009 ↗
12. Multiscale modelling of the morphology and spatial distribution of θ′ precipitates in Al-Cu alloys10.1016/j.actamat.2017.04.042 ↗
13. Multiscale modelling of precipitation hardening in Al-Cu alloys: dislocation dynamics simulations and experimental validation10.1016/j.actamat.2020.02.019 ↗
14. An analysis of the influence of the precipitate type on the mechanical behavior of Al - Cu alloys by means of micropillar compression tests10.1016/j.actamat.2020.05.040 ↗
15. Interface Dislocations and Glide Dislocations on θ′ Precipitates in an Al-4%Cu Alloy
16. On the Interaction between dislocations and decomposition products in an Al-4% Cu Alloy
17. Elevated temperature microstructural stability in cast AlCuMnZr alloys through solute segregation10.1016/j.msea.2019.138279 ↗
18. Modelling the inelastic scattering of fast electrons10.1016/j.ultramic.2014.10.011 ↗
19. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set10.1016/0927-0256(96)00008-0 ↗
20. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set10.1103/PhysRevB.54.11169 ↗
21. Assessing the performance of recent density functionals for bulk solids10.1103/PhysRevB.79.155107 ↗
22. Multiscale modeling of θ′ precipitation in Al-Cu binary alloys10.1016/j.actamat.2004.03.001 ↗
23. Interfacial stability of θ′/Al in Al-Cu alloys10.1016/j.scriptamat.2018.09.018 ↗
24. Possibilities and limitations for the differentiation of elements in the electron microscope
25. Resolution and contrast in the scanning transmission electron microscope
26. Optimizing atomic number contrast in annular dark field images of thin films in the scanning transmission electron microscope
27. Catalyst particle sizes from Rutherford scattered intensities10.1111/j.1365-2818.1989.tb02920.x ↗
28. The synergistic role of Mn and Zr/Ti in producing θ′/L12 co-precipitates in Al-Cu alloys10.1016/j.actamat.2020.05.043 ↗
29. Solute segregation at the Al/θ′-Al2Cu interface in Al-Cu alloys10.1016/j.actamat.2017.09.020 ↗
30. The role of Si in determining the stability of the θ′ precipitate in Al-Cu-Mn-Zr alloys10.1016/j.jallcom.2020.158152 ↗
31. An electron microscope investigation of the interfacial structure of semi-coherent precipitates10.1080/14786436808223031 ↗
32. A high-resolution transmission electron microscopy investigation of the δ'–θ' precipitate structure in an Al-2 wt% Li-1 wt% Cu alloy10.1080/01418618808204528 ↗
33. Atomistic calculations of interfacial energies, nucleus shape and size of θ′ precipitates in Al-Cu alloys10.1016/j.actamat.2006.06.010 ↗
34. Influence of atom termination and stacking sequence on the θ′/Al interfaces from first-principles calculations10.1016/j.spmi.2016.04.026 ↗
35. First-principles/Phase-field modeling of θ′ precipitation in Al-Cu alloys10.1016/j.actamat.2017.08.046 ↗
36. Efficient atomic-scale kinetics through a complex heterophase interface
37. Elastic accommodation of semicoherent θ′ in Al-4wt.%Cu alloy10.1016/0001-6160(78)90135-9 ↗
38. Ledge structure and the mechanism of θ′ precipitate growth in Al-Cu10.1002/pssa.2210800128 ↗
39. The magic thicknesses of θ′ precipitates in Sn-microalloyed Al-Cu10.1016/j.actamat.2011.10.015 ↗