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Nanoaluminium: Is There any Relationship between Particle Size, Non-isothermal Oxidation Data and Ballistics?

Gromov A., Teipel U.

Central European Journal of Energetic Materials

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2017

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Vol. 14, no. 3

501--519

EN

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 = −0.0071x2 + 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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Study of Non-isothermal Nitridation of Aluminum Nanopowders Passivated by Non-oxide Layers

Gromov A., Förter-Barth U., Teipel U.

Central European Journal of Energetic Materials

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2006

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Vol. 3, nr 1-2

65-72

EN

Results of DTA-TG investigation and chemical analysis of electro-exploded aluminum nanopowders coated and/or passivated with the reactive reagents: nitrocellulose (NC), oleic (C17H33COOH) and stearic (C17H35COOH) acids, amorphous boron and air (for a comparison) are discussed. Surface protection of aluminum nanopowders by coatings of different origin results in significant advantages in the energetic properties of the powders. Aluminum nanopowders with a protecting surface show increased stability to oxidation during storage period.

3

Particle Design of Energetic Materials

Teipel U.

Central European Journal of Energetic Materials

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2005

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Vol. 2, nr 2

55-69

EN

The crystal quality and the internal microstructure of crystals have a great influence on the sensitivity of energetic materials. Besides, the particle size and the particle size distribution are of great importance to the processing technology of energetic materials. Particle properties can especially be influenced by applying different crystallization techniques, such as cooling crystallization, membrane crystallization, emulsion crystallization and others. The objective of the investigations was to determine the interrelationship between the properties of the gained crystals and the process parameters. Special attention was directed to the qualitative and quantitative examination of crystal defects and their dependence on the experimental conditions. Besides, the morphology and structure of crystals were calculated by molecular modelling. The effect of crystal defects on the sensitivity of the material was tested on different collectives of particles having varying amount of crystal defects.