Chemistry and structure of core/double-shell nanoscale precipitates in Al–6.5Li–0.07Sc–0.02Yb (at.%)

Monachon, Christian; Krug, Matthew E.; Seidman, David N.; Dunand, David C.

doi:10.1016/j.actamat.2011.02.015

Cited by 52 publications

(11 citation statements)

References 82 publications

(126 reference statements)

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“…One of the most promising approaches to improve the mechanical properties of aluminium alloys is based on the addition of alloying elements either with low solubility or totally insoluble in aluminium. Among the range of possible elements, Scandium is the most effective precipitation hardener element in Al alloys [1][2][3][4]. Heat treatments in the range of 250-350°C, reported to promote considerably precipitation hardening in Al(Sc) alloys with Sc content up to 1 wt.% [5,6].…”

Section: Introductionmentioning

confidence: 98%

The effect of Sc additions on the microstructure and age hardening behaviour of as cast Al–Sc alloys

et al. 2012

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a b s t r a c tThe grain refinement effect and the ageing behaviour of Al-0.5 wt.% Sc, Al-0.7 wt.% Sc, and Al-1 wt.% Sc alloys are studied on the basis of optic microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) observations and hardness measurements. In Al-Sc alloys the higher grain refinement is observed for Sc contents greater than 0.5 wt.% accompanied by a notorious morphology modification, from coarse columnar grains to a fine perfect equiaxed structure. The as cast structures are characterized by a rich supersaturated solid solution in Sc, that promotes a great age hardening response at 250°C and 300°C. The age hardening curves also demonstrate a low overageing kinetics for all the alloys. Although the higher Sc content in solid solution for the alloys with 0.7 and 1 wt.% Sc, the age hardening response of all the Al-Sc alloys remains similar. The direct age hardening response of the as cast Al-0.5 wt.% Sc is shown to be greater than the solutionised and age hardened alloy.

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Section: Introductionmentioning

confidence: 98%

The effect of Sc additions on the microstructure and age hardening behaviour of as cast Al–Sc alloys

et al. 2012

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“…Aberration-corrected scanning and conventional transmission electron microscopy (S/TEM) 28 29 30 31 and soft X-ray imaging/spectroscopy 32 have been used to spatially map the transition metal cations within Li-ion battery cathodes, but these techniques do not have sufficient sensitivity to map Li at sub-nanometre scales, especially in three-dimensional (3D). Atom probe tomography (APT) is uniquely capable of providing quantitative 3D, sub-nanometre-scale compositional characterization of oxides and composites 33 34 35 36 37 38 , with sensitivity for the Li, the O, and the transition metal cations 39 40 41 42 43 44 45 46 47 48 49 50 in a Li-ion cathode material. While Li 1.2 Ni 0.2 Mn 0.6 O 2 is expected to be a two-phase mixture, LiNi 0.5 Mn 1.5 O 4 is expected to have a uniform cation distribution, providing a baseline evaluation of the ability of APT in unambiguously analysing the Li distribution in Li-ion battery cathode materials.…”

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confidence: 99%

Visualizing nanoscale 3D compositional fluctuation of lithium in advanced lithium-ion battery cathodes

et al. 2015

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The distribution of cations in Li-ion battery cathodes as a function of cycling is a pivotal characteristic of battery performance. The transition metal cation distribution has been shown to affect cathode performance; however, Li is notoriously challenging to characterize with typical imaging techniques. Here laser-assisted atom probe tomography (APT) is used to map the three-dimensional distribution of Li at a sub-nanometre spatial resolution and correlate it with the distribution of the transition metal cations (M) and the oxygen. As-fabricated layered Li1.2Ni0.2Mn0.6O2 is shown to have Li-rich Li2MO3 phase regions and Li-depleted Li(Ni0.5Mn0.5)O2 regions. Cycled material has an overall loss of Li in addition to Ni-, Mn- and Li-rich regions. Spinel LiNi0.5Mn1.5O4 is shown to have a uniform distribution of all cations. APT results were compared to energy dispersive spectroscopy mapping with a scanning transmission electron microscope to confirm the transition metal cation distribution.

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“…Material workers have found that rareearth elements are of great importance to improve the service performance of Al-based alloys [6][7][8][9][10]. On a per-atom basis, scandium (Sc) has the greatest strengthening effect of any existing alloying addition to Al [11][12][13]. Moreover, recent researches indicate that additions of minor zirconium to aluminum alloys with scandium enhance positive effect on the set of their operational properties, due to the formation of extremely fine, coherent Al 3 (Sc, Zr) particles with L1 2 structure, which can substantially inhibit recrystallization and pin dislocations [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Evolution of microstructure and properties in a new type 2mm Al–Zn–Mg–Sc–Zr alloy sheet

Deng

Yin

Duan

et al. 2012

Journal of Alloys and Compounds

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Chemistry and structure of core/double-shell nanoscale precipitates in Al–6.5Li–0.07Sc–0.02Yb (at.%)

Cited by 52 publications

References 82 publications

The effect of Sc additions on the microstructure and age hardening behaviour of as cast Al–Sc alloys

The effect of Sc additions on the microstructure and age hardening behaviour of as cast Al–Sc alloys

Visualizing nanoscale 3D compositional fluctuation of lithium in advanced lithium-ion battery cathodes

Evolution of microstructure and properties in a new type 2mm Al–Zn–Mg–Sc–Zr alloy sheet

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