Heterogeneous nucleation of T1 precipitates in solid solution of Al-Cu-Li alloys from Ag-rich structures: An ab initio study

Wang, Shuo; Xue, Chengpeng; Yang, Xinghai; Tian, Guangyuan; Wang, Junsheng

doi:10.1016/j.scriptamat.2022.115191

Cited by 27 publications

(4 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on the density functional theory (DFT), the Vienna ab initio Simulation Package (VASP) software package was applied to the structural relaxation and ideal tensile strength. − The generalized gradient approximation (GGA) of the form of Perdew Burke Ernzerhof (PBE) was utilized as an electronic exchange and correlations. − The cutoff energy of 500 eV was selected as the plane-wave basis vector by convergence tests. The Brillouin zone is divided by using the Monkhorst–Pack method for k points, where the BCC Li/Mg 2 Sn interface, HCP-Mg/Mg 2 Sn interface, and BCC Li/HCP Mg interface are 5 × 5 × 1, 5 × 2 × 1, and 11 × 2 × 1, respectively.…”

Section: Methods and Modelsmentioning

confidence: 99%

Uncovering the Interfacial Strengthening Mechanisms of α-Mg/Mg₂Sn/β-Li Interfaces Using First-Principle Calculations and HAADF-STEM

Tian,

Wang,

Wang

et al. 2024

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

Previously, we reported our new invention of an ultralight (ρ = 1.61 g/cm 3 ) and super high modulus (E = 64.5 GPa) Mg−Li−Al−Zn−Mn−Gd−Y−Sn (LAZWMVT) alloy. Surprisingly, the minor additions of Sn contribute to significant strength and stiffness increases. In this study, we found that Mg 2 Sn was not only the simple precipitate but also acted as the glue to bind the α-Mg/β-Li interface in a rather complicated way. To explore its mechanism, we have performed first-principle calculations and HAADF-STEM experiments on the interfacial structures. It was found that the interfacial structural models of α-Mg/β-Li, α-Mg/Mg 2 Sn, and β-Li/ Mg 2 Sn composite interfaces prefer to form α-Mg/Mg 2 Sn/β-Li ternary composite structures due to the stable formation enthalpy (ΔH: −1.95 eV/atom). Meanwhile, the interface cleavage energy and critical cleavage stress show that Mg 2 Sn contribute to the interfacial bond strength better than the β-Li/α-Mg phase bond strength (σ b (β-Li/Mg 2 Sn): 0.82 GPa > σ b (α-Mg/Mg 2 Sn): 0.78 GPa > σ b (β-Li/α-Mg): 0.62 GPa). Based on the interfacial electronic structure analysis, α-Mg/Mg 2 Sn and β-Li/Mg 2 Sn were found to have a denser charge distribution and larger charge transfer at the interface, forming stronger chemical bonds. Additionally, according to the crystal orbital Hamiltonian population analysis, the bonding strength of the Mg−Sn atom pair was 2.61 eV, which was higher than the Mg−Li bond strength (0.39 eV). The effect of the Mg 2 Sn phase on the stability and interfacial bonding strength of the alloying system was dominated by the formation of stronger and more stable Mg−Sn metal covalent bonds, which mainly originated from the contribution of the Mg 3p-Sn 5p orbital bonding states.

show abstract

Section: Methods and Modelsmentioning

confidence: 99%

Uncovering the Interfacial Strengthening Mechanisms of α-Mg/Mg₂Sn/β-Li Interfaces Using First-Principle Calculations and HAADF-STEM

Tian,

Wang,

Wang

et al. 2024

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

show abstract

“…7, a Shockley partial dislocation (b p =a/6 ) was formed with the removal of a single A layer, which induced an intrinsic stacking fault. A hexagonal-close-packed (hcp) structure bounded by partial dislocations around the stacking fault region was formed, consisting of an hcp doublelayer 35,36 . The solutes tended to segregate around the stacking fault region to change the stacking fault energy 37 .…”

Section: Microstructural Evolutionmentioning

confidence: 99%

Strength–ductility materials by engineering a coherent interface at incoherent precipitates

Mao,

Xie,

Meng

et al. 2024

Mater. Horiz.

View full text Add to dashboard Cite

show abstract

“…As one of the major strengthening mechanisms in Al‐Li alloys, precipitation strengthening is of great interests to many researchers [8–12] . Among them, the nano T 1 precipitate with high length/diameter ratios is the most important and has been well‐studied in the third and fourth‐generation Al‐Li alloys.…”

Section: Introductionmentioning

confidence: 99%

“…Combining high‐throughput first‐principles calculations and atomic‐resolution HAADF‐STEM imaging, recently, we proposed an accurate atomic model for T 1 precipitate that can maintain the stabilization in finite‐temperatures Al‐Cu‐Li ternary phase diagram [10] ; subsequently, we proposed that the heterogeneous nucleation of T 1 can be achieved by Ag‐enriched clusters using elaborate first‐principles calculations [11] . These foundations are enlightening for understanding the nucleation process of T 1 precipitates.…”

Section: Introductionmentioning

confidence: 99%

Unexpected nucleation mechanism of T₁ precipitates by Eshelby inclusion with unstable stacking faults

Wang,

Xue

et al. 2024

Materials Genome Engineering Advances

Self Cite

View full text Add to dashboard Cite

Aluminum‐lithium (Al‐Li) alloy is one of the most promising lightweight structural materials in the aeronautic and aerospace industries. The key to achieving their excellent mechanical properties lies in tailoring T1 strengthening precipitates; however, the nucleation of such nanoparticles remains unknown. Combining atomic resolution HAADF‐STEM with first‐principles calculations based on the density functional theory (DFT), here, we report a counterintuitive nucleation mechanism of the T1 that evolves from an Eshelby inclusion with unstable stacking faults. This precursor is accelerated by Ag‐Mg clusters to reduce the barrier, forming the structural framework. In addition, these Ag‐Mg clusters trap the free Cu and Li to prepare the chemical compositions for T1. Our findings provide a new perspective on the phase transformations of complex precipitates through solute clusters in terms of geometric structure and chemical bonding functions.

show abstract

Heterogeneous nucleation of T1 precipitates in solid solution of Al-Cu-Li alloys from Ag-rich structures: An ab initio study

Cited by 27 publications

References 31 publications

Uncovering the Interfacial Strengthening Mechanisms of α-Mg/Mg₂Sn/β-Li Interfaces Using First-Principle Calculations and HAADF-STEM

Uncovering the Interfacial Strengthening Mechanisms of α-Mg/Mg₂Sn/β-Li Interfaces Using First-Principle Calculations and HAADF-STEM

Strength–ductility materials by engineering a coherent interface at incoherent precipitates

Unexpected nucleation mechanism of T₁ precipitates by Eshelby inclusion with unstable stacking faults

Contact Info

Product

Resources

About

Heterogeneous nucleation of T1 precipitates in solid solution of Al-Cu-Li alloys from Ag-rich structures: An ab initio study

Cited by 27 publications

References 31 publications

Uncovering the Interfacial Strengthening Mechanisms of α-Mg/Mg2Sn/β-Li Interfaces Using First-Principle Calculations and HAADF-STEM

Uncovering the Interfacial Strengthening Mechanisms of α-Mg/Mg2Sn/β-Li Interfaces Using First-Principle Calculations and HAADF-STEM

Strength–ductility materials by engineering a coherent interface at incoherent precipitates

Unexpected nucleation mechanism of T1 precipitates by Eshelby inclusion with unstable stacking faults

Contact Info

Product

Resources

About

Uncovering the Interfacial Strengthening Mechanisms of α-Mg/Mg₂Sn/β-Li Interfaces Using First-Principle Calculations and HAADF-STEM

Uncovering the Interfacial Strengthening Mechanisms of α-Mg/Mg₂Sn/β-Li Interfaces Using First-Principle Calculations and HAADF-STEM

Unexpected nucleation mechanism of T₁ precipitates by Eshelby inclusion with unstable stacking faults