Segregation and precipitation stabilizing an ultrafine lamellar-structured Al-0.3%Cu alloy

Shuai, Linfei; Huang, Tianlin; Yu, Tianbo; Wu, Guilin; Hansen, Niels; Huang, Xiaoxiao

doi:10.1016/j.actamat.2020.116595

Cited by 16 publications

(6 citation statements)

References 61 publications

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“…During migration of the Y-junction shown in figure 4, an externally attached interconnecting boundary on the left-hand side interacted with the Y-junction, retarding its migration. Such a pinning effect was also found for attached lamellar boundaries, particles, and dislocations [29,36]. The geometry of a Y-junction is important in determining its stability, in particular the spacing D and the dihedral angle 2θ associated with the migrating lamella.…”

Section: Uniform Coarsening By Y-junction Motionmentioning

confidence: 76%

Microstructural evolution during recovery of deformed aluminium—Effect of deformation strain

2022

IOP Conf. Ser.: Mater. Sci. Eng.

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Recovery takes place during annealing of a deformed metal, releasing some of the stored energy. Many recovery mechanisms have been proposed in the literature and these mechanisms strongly depend on the deformation microstructure. In this work, recent progress in the study of recovery in aluminium is reviewed. In lightly deformed aluminium, subgrain growth (through boundary migration and coalescence) is found to be an important recovery mechanism, whereas in heavily deformed samples, uniform coarsening through Y-junction motion is found to be the dominant recovery mechanism. The kinetics of recovery follows a universal coarsening model for aluminium deformed to both low and high strains, in which the apparent activation energy increases in the course of recovery. Furthermore, a new definition of recovery is suggested to be compatible with observations at both low and high strains.

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Section: Uniform Coarsening By Y-junction Motionmentioning

confidence: 76%

Microstructural evolution during recovery of deformed aluminium—Effect of deformation strain

2022

IOP Conf. Ser.: Mater. Sci. Eng.

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“…Compared with the solution treated sample [9], finer lamellae are observed in regions deeper from the surface, which indicates that the precipitation introduced by aging treatment before deformation can effectively inhibit dynamic recovery of the alloy during deformation. Shuai et al [17] observed the pinning phenomenon of Al 2 Cu particles to triple junctions in Al-0.3wt.%Cu by insitu electron microscopy, indicating that the second phase particles can improve the stability of the alloy. This stabilization mechanism also plays an important role in the deformation process of the samples in the aging state.…”

Section: Methodsmentioning

confidence: 99%

“…Due to the low diffusion capability at low deformation temperature, these atoms still remain around the decomposed precipitates. Segregation and precipitation in the peak-aged sample can stabilize the grain boundaries from both a thermodynamic and kinetic perspective, and restrain dynamic recovery in the deformation process [17], which leads to thinner lamellar spacing compared with solute-treated SSFT samples [9]. APT can provide abundant 3D chemical information but limited crystallographic knowledge, while 3D-OMiTEM is an effective complementary technique.…”

Section: D-omitem Observationsmentioning

confidence: 99%

3D characterization of a nanostructured Al-Cu-Mg alloy

Zhu

Yang²,

Feng³

et al. 2022

IOP Conf. Ser.: Mater. Sci. Eng.

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Three-dimensional (3D) characterization of variations in crystallography and chemistry of nanostructured metals will provide vital information to understand their mechanical and thermal behaviours. This study applied a surface sliding friction treatment (SSFT) at liquid nitrogen temperature to produce nanostructured surface layers in a peak-aged Al-Cu-Mg alloy. The nanostructured surface was characterized by means of 3D orientation mapping in the transmission electron microscope (3D-OMiTEM) and atom probe tomography (APT). 3D-OMiTEM results revealed a lamellar structure with an average lamellar boundary spacing of 26 nm at the topmost surface layer (depth < 20 μm), which is much finer than normally achievable in commercial purity Al deformed to high strain levels. Based on the 3D-OMiTEM data, a five-parameter grain boundary character analysis was carried out. It was found that low angle grain boundaries dominate the nanoscale structure and that the grain boundary plane distribution of high angle lamellar grain boundaries shows a preference around {101}. APT analysis showed segregation of Cu and Mg atoms at lamellar boundaries, which is believed to play a role in stabilizing the boundaries and enhancing the structural refinement during SSFT.

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“…However, the effects of TJs on strength were largely overlooked. Some researchers have also noticed the connection between TJs and dislocation nucleation [11,12] and GB activities, [13,14] which are essential factors in determining the strength of polycrystalline materials. By in situ compression of coarse-grained and nano-grained nanoporous gold samples in an electrochemical environment, [8] the effect of surface triple junction (STJ) on the strength of nanoporous gold was successfully decoupled from the GB and surface effects.…”

Section: Introductionmentioning

confidence: 99%

“…And for the annealing recrystallization process of layered polycrystalline aluminum or nickel in the cold rolled state, the dominant role of Y‐junctions in the process of GB coordination deformation is demonstrated. [ 13–15 ] Moreover, atomic‐scale simulations [ 16 ] also proved that the drag obstruction of TJs on adjacent GBs is more pronounced at small sizes, low Σ GBs, or low temperatures. This effect affects the dihedral angle size of TJs, which in turn further affects the migration of TJs.…”

Section: Introductionmentioning

confidence: 99%

Grain Distribution for Optimal Strength in Homogeneous and Gradient Nano‐Grained Coppers

Qiang

Long

2023

Adv Eng Mater

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The distribution of grains plays a crucial role in determining the strength of polycrystalline copper when the grain size is constant. Herein, the mechanical properties of homogeneous nano‐grained (HNG) and gradient nano‐grained (GNG) coppers with different grain distributions are examined using molecular dynamics (MD) simulations. The HNG‐ordered structure has all triple junctions (TJs), whereas the random structure contains many quadruple and quintuple junctions. When grain size is below the critical size in the inverse Hall–Petch relationship, the high‐density TJs in the HNG‐ordered structure effectively inhibit grain boundary (GB) softening compared with the random structure, leading to higher strength. However, when grain size is above the critical size, subgrains are produced inside the large grains due to dislocation slip. In addition, disordered atoms in HNG‐random structure are stacked in the quadruple and quintuple junctions, resulting in thicker GBs. This triggers grain boundary migration, and forms more subgrains at GBs. Subsequently, grain boundary sliding and grain rotation of subgrains induce partial recrystallization in the structure. This consecutively triggered deformation mechanism leads to extra strengthening in the random structure. Further research indicates that combining small‐grained ordered and large‐grained random structures can be a new approach to effectively strengthen GNG materials.

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Segregation and precipitation stabilizing an ultrafine lamellar-structured Al-0.3%Cu alloy

Cited by 16 publications

References 61 publications

Microstructural evolution during recovery of deformed aluminium—Effect of deformation strain

Microstructural evolution during recovery of deformed aluminium—Effect of deformation strain

3D characterization of a nanostructured Al-Cu-Mg alloy

Grain Distribution for Optimal Strength in Homogeneous and Gradient Nano‐Grained Coppers

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