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Popenko, E. M.; Il’in, A. P.; Gromov, A. M.; Kondratyuk, S. K.; Surgin, V. A.; Gromov, A. A.

doi:10.1023/a:1014994630495

Cited by 15 publications

(4 citation statements)

References 6 publications

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“…Thus, the smaller amount of Al inside the Al 2 O 3 shell for an aged particle heated faster and ignited more easily in comparison with the non-aged particle where the amount of Al metal was larger [42]. This experimental phenomenon was also confirmed for µAl particles: aged powders were easily ignited and burnt in air while fresh ones did not [43].…”

Section: Experimental Data On the Nal Slow Oxidationmentioning

confidence: 57%

“…However at higher oxidation rates on combustion in air, the interaction of aluminium with nitrogen and the subsequent production of AlN should also be taken into account (reaction 4) [42,43]. Nitride formation by aluminium oxidation in air at low oxidation rates (0.5-20.0 K/min) has never been reported in the literature [42,43,57].…”

Section: Analysis Of Powder Characteristics and Their Comparison Withmentioning

confidence: 99%

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Nanoaluminium: is there any Relationship between Powder Particles’ Size, Non-Isothermal Oxidation Data and Ballistics?

Gromov¹,

Teipel²

2017

Cent. Eur. J. Energ. Mater.

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This article focuses on data analyses and comparisons for aluminium nanopowders (or nanoaluminium, nAl) reactions under slow (0.5-20.0 K/min, using DTA/DSC/TGA) and fast (>10000 K/min, combustion in solid propellant formulations) non-isothermal oxidation. Particle sizes were defined through the BET method. Active Al content was related with the averaged reactivity parameters, taken from published DTA/DSC/TGA data. The specific oxidation onset temperature for nAl was poorly correlated with the BET particle size under the conditions investigated. Furthermore, the BET particle size exhibited no correlation with the observed ballistic response (burning rate) at 3.0 MPa. A logarithmic correlation y = 17.484 ln(x) -5813, with R² = 0.73, was found between nAl particle size and its aluminium content. A calibration equation for the oxidation onset temperature as a function of nAl particle size was determined as y = −0.0071x 2 + 3.3173x + 479.32, with R² = 0.75. Specific features of the nAl (metallic aluminum content in nAl and the oxidation onset temperature) can be predicted based on the measured powder parameters (such as BET particle size).

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Section: Experimental Data On the Nal Slow Oxidationmentioning

confidence: 57%

Section: Analysis Of Powder Characteristics and Their Comparison Withmentioning

confidence: 99%

Nanoaluminium: is there any Relationship between Powder Particles’ Size, Non-Isothermal Oxidation Data and Ballistics?

Gromov¹,

Teipel²

2017

Cent. Eur. J. Energ. Mater.

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“…When particles are segregated, flame speeds are higher, but reaction efficiency is poor because larger micron-scale particles are not participating in the reaction because they burn too slowly to contribute to the reaction wave initiated by the smaller The results in flame speeds shown in Table 1 agree with other research that shows smaller particles are more ignition sensitive and thus more easily propagate around larger particles producing increased flame speeds. [59,60] However, what is gained in ignition sensitivity promoting increased flame speeds via segregated particles is sacrificed in performance through more incomplete combustion from larger particles that cannot contribute to the energy liberated and act as thermal boulders that the flame will bypass if a pathway of smaller particles is present to sustain flame propagation.…”

Section: Reactive Characterizationmentioning

confidence: 99%

Effects of Shear Rate during Energetic Material Processing on Reactivity

et al. 2019

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Energetic materials are often processed at high rates of deformation as colloidal slurries and then cured. The slurries are non-Newtonian colloidal solutions that exhibit changes in microstructure with variations in applied flow. This study shows that changes to microstructure due to applied flow affect the reactivity of energetic thin films. Energetic thin films of identical composition and geometry are prepared with different applied shear rates, which produce variations in the film microstructure by segregating smaller particles toward surfaces. Results show that films exhibit significant gains in flame speed with increasing shear rate. The differences in flame speed are linked to variations in microstructure. Specifically, densification of smaller particles near a boundary promote increased flame speeds. However, when particles become segregated, larger particles tend to contribute less to the overall reaction because they burn slowly compared to the smaller particles. When segregated, the larger particles may not be adding chemical energy to the reaction front because propagation is dominated by the more ignition sensitive smaller particles. This study demonstrates explicit changes in reactivity arising from changes in processing conditions that affect microstructure. Controlling applied shear rate introduces a new approach to regulating energetic material reactivity when processed using extrusion-based advanced manufacturing techniques.

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“…Thus, not only the active metal content of the Al powder should be considered for an evaluation of its effects on the condensed energetic material, but also the additive reactivity (i.e., residual CAl, its intense oxidation onset temperature and its ability to be exothermically converted to the metal oxide). Both initial particle size (µAl vs. nAl) and ageing characteristics (i.e., surface composition and permeability) play a significant role in the understanding of the energetic filler effects on the ballistic response of different systems [17,18]. This paper investigates the accelerated ageing behavior of aluminum powders with various particle sizes.…”

Section: Introductionmentioning

confidence: 99%