In-situ transmission electron microscopy determination of solid-state diffusion in the aluminum-nickel system

Pauls, Joshua M.; Shuck, Christopher E.; Genç, Arda; Rouvimov, Sergei; Mukasyan, Alexander S.

doi:10.1016/j.jssc.2019.04.024

Cited by 19 publications

(9 citation statements)

References 43 publications

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“…Initial observations reveal that measured microburn rates (local vector burn rate at the microscopic scale, details could be found in Figure S2) are lower than the corresponding global burn rates. Similar to studies on other heterogeneous systems, − we find that the flame front is not planar but corrugated. The microscopic snapshots of the three samples at selected times are shown in Figure a–c.…”

Section: Resultssupporting

confidence: 87%

“…While a flame front of a thermite reaction may appear planar under a macroscopic (normal) view, it may appear quite different under a microscopic observation. When observed at a temporal and spatial resolution of ∼10 –1 s and ∼0.1 mm, respectively, it has been shown that many other heterogeneous systems (e.g., Ti–C, Ni–Al) exhibit a planar combustion wave; however, at higher resolutions, the propagation appears to be much more discrete with deviations from a unimodal velocity distribution and nonuniform temperature distributions along the reaction front. − …”

Section: Resultsmentioning

confidence: 99%

“…The ignition temperatures/delays, burn rates, and thermal decomposition properties have also been characterized on the macroscopic scale. − ,− , However, there is limited literature on the microscopic characterization of the reaction. While most of these studies have focused on gasless self-propagating high-temperature synthesis (SHS) systems such as Al/Ni nanolaminates, ,− few efforts have focused on thermites …”

Section: Introductionmentioning

confidence: 99%

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Probing the Reaction Zone of Nanolaminates at ∼μs Time and ∼μm Spatial Resolution

et al. 2020

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Reactive nanolaminates are a high-energy-density configuration for energetics that have been widely studied for their tunable energy release rates. In this study, we characterized Al/CuO nanolaminate reactions with different fuel/oxidizer ratios and bilayer thicknesses using both macro- and microscale high-speed imaging/pyrometry. Under microscopic imaging, we observe significant corrugation (the ratio of the total geometrical length of the flame to the width of the sample in the direction perpendicular to propagation) of the flame, which can increase the reaction surface area by as much as a factor of 3. This in turn manifests itself as an increase in the global burn rate (total nanolaminate film length/total burn time). We find that the global burn rate can be predicted as the product of the microburn rate (local vector burn rate at the microscopic scale) and the corrugation. These corrugation effects primarily impact fuel-rich conditions, resulting in higher global burn rates. We find that the reaction zone has a thickness of ∼150 μm. Finally, we present a 3D rendering of what we believe the reaction zone looks like, based on the results from in-operando observation and SEM cross-sectional imaging.

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Section: Resultssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Probing the Reaction Zone of Nanolaminates at ∼μs Time and ∼μm Spatial Resolution

et al. 2020

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“…The application of the correlation procedure yields an E a = 107 kJ mol −1 . The obtained value agrees with the results obtained in [57,58]. For the following numerical investigations, this value was used for the activation energy.…”

Section: Influence Of Premixingsupporting

confidence: 85%

“…The reaction front velocity decreases with increasing the activation en following an exponential rule introduced in [56] and later implemented by [9,36] The application of the correlation procedure yields an 𝐸 = 107 kJ mol −1 . The o value agrees with the results obtained in [57,58]. For the following nu investigations, this value was used for the activation energy.…”

Section: Adjustment Of Model Parameterssupporting

confidence: 84%

Influence of Initial Temperature and Convective Heat Loss on the Self-Propagating Reaction in Al/Ni Multilayer Foils

et al. 2021

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A two-dimensional numerical model for self-propagating reactions in Al/Ni multilayer foils was developed. It was used to study thermal properties, convective heat loss, and the effect of initial temperature on the self-propagating reaction in Al/Ni multilayer foils. For model adjustments by experimental results, these Al/Ni multilayer foils were fabricated by the magnetron sputtering technique with a 1:1 atomic ratio. Heat of reaction of the fabricated foils was determined employing Differential Scanning Calorimetry (DSC). Self-propagating reaction was initiated by an electrical spark on the surface of the foils. The movement of the reaction front was recorded with a high-speed camera. Activation energy is fitted with these velocity data from the high-speed camera to adjust the numerical model. Calculated reaction front temperature of the self-propagating reaction was compared with the temperature obtained by time-resolved pyrometer measurements. X-ray diffraction results confirmed that all reactants reacted and formed a B2 NiAl phase. Finally, it is predicted that (1) increasing thermal conductivity of the final product increases the reaction front velocity; (2) effect of heat convection losses on reaction characteristics is insignificant, e.g., the foils can maintain their characteristics in water; and (3) with increasing initial temperature of the foils, the reaction front velocity and the reaction temperature increased.

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Nanocalorimetry of Nanoscaled Ni/Al Multilayer Films: On the Methodology to Determine Reaction Kinetics for Highly Reactive Films

Riegler,

Sauni Camposano,

Jaekel

et al. 2024

Adv Eng Mater

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Free‐standing Ni/Al multilayer films with a planar morphology, a bilayer thickness of 20 nm and an average composition of Ni50Al50 (at.–%) deposited by direct current magnetron sputtering are investigated by nanocalorimetry and conventional calorimetry. Both the novel fast differential scanning calorimeter (FDSC) Flash DSC 2+ from Mettler‐Toledo (MT) and conventional calorimeter MT DSC 3 were used to cover a range of heating rates from 0.1 K s–1 to 104 K s–1. A quantitative kinetic study of the interdiffusion and phase reaction sequence was performed via a Kissinger analysis covering five orders of magnitude of heating rates. Using the calorimetric data, the derived apparent activation energies suggest monotonic reaction kinetics over the entire range of heating rates applied. In order to correct the thermal lag at the highest heating rates with the FDSC for non‐adhered free‐standing films, a new methodology for its correction was used. Overall, this work extends the application of commercial FDSC to non‐adhered films.This article is protected by copyright. All rights reserved.

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In-situ transmission electron microscopy determination of solid-state diffusion in the aluminum-nickel system

Cited by 19 publications

References 43 publications

Probing the Reaction Zone of Nanolaminates at ∼μs Time and ∼μm Spatial Resolution

Probing the Reaction Zone of Nanolaminates at ∼μs Time and ∼μm Spatial Resolution

Influence of Initial Temperature and Convective Heat Loss on the Self-Propagating Reaction in Al/Ni Multilayer Foils

Nanocalorimetry of Nanoscaled Ni/Al Multilayer Films: On the Methodology to Determine Reaction Kinetics for Highly Reactive Films

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