Characterization of Aluminum Nanopowder Compositions

Abstract

The thermal behaviour of two different Al nanopowders and a micron‐sized Al powder was studied using DSC, simultaneous TG‐DTA, and accelerating rate calorimetry (ARC). The results show that the reactivity of Al powder increases as the particle size decreases. The thermal stability of the smaller Al nanopowder (Als) in water and in a humid atmosphere was determined using ARC and TG‐DTA, respectively. Atomic Absorption Spectrometry (AAS), X‐Ray Photoelectron Spectrometry (XPS) and Auger Electron Spectrometry (AES) were used to characterize the surface chemistry of Alex. The outgassing behaviour for mixtures of RDX and the various Al powders was investigated using TG‐DTA‐FTIR‐MS. Evolution of NO2 and N2O from a chemical interaction between Al nanopowders and RDX was observed. The effect of Als and Alex on the thermal stability of TNT, RDX, Comp B, and AP was determined using ARC. Addition of Als significantly lowered the onset temperature for TNT and RDX decomposition. Electrostatic discharge (ESD) sensitivities of Al nanopowders and their mixtures with TNT, Comp B, RDX and AP were determined. The results show that the AP/Als mixture is very sensitive to ESD. Standard dust explosibility tests demonstrated that Alex is highly explosible.

Density Functional Theory Studies on the Adsorption of NH2NO2 on Al13 Cluster

“…Al clusters are among the most interesting and the most studied metal clusters since aluminum is one of the most used industrial metals, which has abroad range of current and potential applications. For example, aluminum powders are widely used as propellants, because their combustion products of Al 2 O 3 are accompanied by a large amount of heat release, and the burn rates of aluminum powders can be accelerated by reducing the size of Al particles [7,8]. The intriguing applications of Al clusters as high energetic materials offer most desirable qualities of high heat release rates, extraordinary combustion efficiency, tailored burning rate, and reduced sensitivity [9].…”

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

“…An overview of the Jones et al and Kwok et al experimental results on nAl powders and their effect on energetic systems is reported in [38][39][40][41]. The ageing of Alex powder during storage causes the oxidation onset temperature to decrease [41].…”

“…The formation of nano γ-Al 2 O 3 by slow non-isothermal oxidation (0.5-20.0 K/min) occurs at low temperatures (T = 673-773 K) for electroexplosive nAl [23]. Furthermore, the different definitions of the intense oxidation onset temperature and other parameters on the DTA/DSC/TGA curves can lead to confusing comparisons Copyright © 2017 Institute of Industrial Organic Chemistry, Poland between different datasets [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]. For certain nAl samples with a specific surface area 12 m 2 /g, the mass fraction of micron-sized particle clusters (1-3 µm) could be 68 wt.%, but the number of clusters was only 2% of the total number of particles [56].…”

Ignition Behavior of Al/Fe2O3 Metastable Intermolecular Composites

“…Similar behavior has been reported for nano Alex by Jones et al [41]. They have explained that the weight gain is due to nitridation on the surface of nano Al or of the un-reacted Al core [42] which is described as follows (Eq. 2) …”