Role of silicon in accelerating the nucleation of Al3(Sc,Zr) precipitates in dilute Al–Sc–Zr alloys

Booth-Morrison, Christopher; Mao, Zugang; Diaz, Mauricio C.; Dunand, David C.; Wolverton, Christopher; Seidman, David N.

doi:10.1016/j.actamat.2012.05.036

Cited by 174 publications

(51 citation statements)

References 90 publications

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“…The likely existence of Si atoms in the liquid aluminum, leached from the Saffil fibers during the time the Al-Sc-Zr matrix of the 15 vol.% Saffil composite is liquid, may explain the unexpected formation of Al 3 (Sc,Zr) nano-precipitates during slow cooling after solidification. In prior work, 20,26,27 the precipitation kinetics of Sc and Zr were shown to be strongly accelerated by the addition of small concentrations of Si. For example, Si at the impurity level (0.025 at.%) increases the nucleation current of Al 3 Sc in dilute Al-Sc alloys, with the Sc concentration in the range 0.025-0.065 at.%.…”

Section: Strengthening Mechanism Of Nanoscale Al 3 (Sczr) Precipitatesmentioning

confidence: 94%

“…29 A dilute Al-0.06 Sc-0.06 Zr at.% alloy with 0.06 at.% Si also exhibited faster precipitate nucleation and growth, as compared to an alloy without Si. 26 It was hypothesized that Si binds with Sc and/or Zr atoms, where the Si-Sc and Si-Zr dimers have faster diffusivities in the a-Al matrix when compared to the individual Sc and Zr atoms, respectively. 26 Finally, a recent systematic study of the effect of Si, with concentrations in the range 0-0.2 at.% in the dilute Al-0.55 Sc-0.02 Zr-0.005 Er at.% demonstrated that the higher the Si concentration, the faster the precipitation kinetics of (Al,Si) 3 (Sc,Zr,Er) nano-precipitates, resulting in shorter aging times to achieve the peak strength.…”

Section: Strengthening Mechanism Of Nanoscale Al 3 (Sczr) Precipitatesmentioning

confidence: 99%

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Development of a Precipitation-Strengthened Matrix for Non-quenchable Aluminum Metal Matrix Composites

Sorensen²,

Klier

et al. 2016

JOM

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Recent developments in metal matrix composite-encapsulated ceramic armor show promise in lightweight armor technology. The system contains ceramic tiles, such as alumina, sandwiched between unreinforced aluminum or aluminum metal matrix composite (Al-MMC), which has a better toughness compared to the ceramic tiles. The sandwich structures should not be quenched during the fabrication, as the large mismatch in the coefficients of thermal expansion between the ceramic tiles and the unreinforced aluminum or Al-MMC creates internal stresses high enough to fracture the ceramic tiles. However, slow cooling of most commercial alloys creates large precipitates making solute unavailable for the formation of fine precipitates during aging. Here, we develop a non-quenched, high-strength metal matrix utilizing dilute Al-Sc-Zr alloys. We demonstrate that the dilute Al-0.09 Sc-0.045 Zr at.% alloy and the same alloy containing 0-4 vol.% alumina short fibers do not result in precipitation upon slow cooling from a high temperature, and can thereafter be aged to increase their strength. They exhibit a moderate strength, but improved ductility and toughness as compared to common armor aluminum alloys, such as AA5083-H131, making them attractive as armor materials and hybrid armor systems.

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Section: Strengthening Mechanism Of Nanoscale Al 3 (Sczr) Precipitatesmentioning

confidence: 94%

Section: Strengthening Mechanism Of Nanoscale Al 3 (Sczr) Precipitatesmentioning

confidence: 99%

Development of a Precipitation-Strengthened Matrix for Non-quenchable Aluminum Metal Matrix Composites

Sorensen²,

Klier

et al. 2016

JOM

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“…It is seen in Figure 7 [6,8,9,36] although at the higher end of the range. However, additions of Si were shown to accelerate the precipitation kinetics in Zr containing alloys [39][40][41][42] and, as stated earlier, Rg measurements are partially driven by the evolution of the precipitate size distribution. Hence, although they provide a valid estimate, these values should be considered as an upper limit of the coarsening rate constant.…”

Section: Analysis Of Precipitate Sizesmentioning

confidence: 99%

Characterising precipitate evolution in multi-component cast aluminium alloys using small-angle X-ray scattering

Wang

McCartney

et al. 2017

Journal of Alloys and Compounds

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The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. AbstractAluminium alloys can be strengthened significantly by nano-scale precipitates that restrict dislocation movement. In this study, the evolution of inhomogenously distributed trialuminide precipitates in two multi-component alloys was characterised by synchrotron small-angle Xray scattering (SAXS). The appropriate selection of reference sample and data treatment required to successfully characterise a low volume fraction of precipitates in multi-component alloys via SAXS was investigated. The resulting SAXS study allowed the analysis of statistically significant numbers of precipitates (billions) as compared to electron microscopy (hundreds). Two cast aluminium alloys with different volume fractions of Al3ZrxV1-x precipitates were studied. Data analysis was conducted using direct evaluation methods on SAXS spectra and the results compared with those from transmission electron microscopy (TEM). Precipitates were found to attain a spherical structure with homogeneous chemical composition. Precipitate evolution was quantified, including size, size distribution, volume fraction and number density. The results provide evidence that these multi-component alloys have a short nucleation stage, with coarsening dominating precipitate size. The coarsening rate constant was calculated and compared to similar precipitate behaviour.2

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“…This change in precipitation kinetics has several practical implications, specifically that while Sc is supersaturated during solidification in Al-Sc binary alloys under conventional cooling rates, Si appears to alter this behaviour to where addition of Si to Al-Sc was shown to result in discontinuous precipitation of coherent Sc dispersoids during post-solidification cooling [16][17][18][19]. Furthermore, Si was also seen to accelerate the nucleation and growth of the Sc dispersoids, hence reducing the time to peak age but simultaneously decreasing their coarsening resistance [20].…”

Section: Introductionmentioning

confidence: 99%

Developing an Optimized Homogenization Process for Sc and Zr Containing Al-Mg-Si Alloys

Babaniaris

Mariappan

Jiang

et al. 2019

The Minerals, Metals &Amp; Materials Series

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Light-weighting of vehicles drives the development of Aluminium alloys with improved strength and formability. An opportunity to achieve this goal is using Scandium (Sc). The beneficial effects from Sc comes from the formation of nanosized Al3Sc dispersoids. Detrimental interactions between Sc and Silicon (Si) has limited the uptake of Sc in 6xxx alloys. The first step towards developing Sc containing 6xxx-series is to understand the as-cast microstructure and the effect of subsequent heat treatment on the dispersoids. This work uses isochronal ageing trials on a series of Al-Mg-Si-(Sc)-(Zr) model alloys. The evolution of hardness and conductivity is recorded to indirectly characterize the precipitate sequence. Transmission electron microscopy is used to further characterize the morphology and kinetics of MgSi precipitates and Sc/Zr dispersoids. The precipitation of Sc was altered by the presence of Si, and hence it is concluded that a non-traditional homogenization treatment is required for these alloys.

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Role of silicon in accelerating the nucleation of Al3(Sc,Zr) precipitates in dilute Al–Sc–Zr alloys

Cited by 174 publications

References 90 publications

Development of a Precipitation-Strengthened Matrix for Non-quenchable Aluminum Metal Matrix Composites

Development of a Precipitation-Strengthened Matrix for Non-quenchable Aluminum Metal Matrix Composites

Characterising precipitate evolution in multi-component cast aluminium alloys using small-angle X-ray scattering

Developing an Optimized Homogenization Process for Sc and Zr Containing Al-Mg-Si Alloys

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