Bimetal Al–Ni nano-powders for energetic formulations

Document Type

Article

Publication Date

11-1-2016

Abstract

Four bimetal Al–Ni nano-powders with compositions varied from 5 to 45 at% of nickel were synthesized by explosion of electrically heated twisted pure Al and Ni wires in argon. The nano-powders were characterized using electron microscopy, x-ray diffraction, and thermal analysis. Materials were ignited using an electrically heated filament coated with powder and electrostatic discharge (ESD). The results were compared to those for pure nano-aluminum powder (n-Al) prepared using the same wire explosion technique. The nano-powders with high nickel concentrations contain fully reacted intermetallic phases, which are difficult to oxidize making them unattractive for energetic formulations. Nano-powders with lower nickel concentrations do not contain significant amounts of the intermetallic phases. No intermetallics were detected in the powder with 5 at% Ni, which oxidized qualitatively similar to n-Al. The overall mass gain during oxidation for the bimetal powder was nearly identical to that of n-Al, suggesting the same heat release anticipated from their combustion. Oxidation kinetics assessed for this material accounting directly for the measured particle size distribution was compared to that of n-Al. The bimetal powder oxidized slower than n-Al, indicating its greater stability during handling and storage. The bimetal powder was less ESD-ignition sensitive than n-Al, but generated a stronger emission signal when ignited. Therefore, the bimetal powder with 5 at% Ni is an attractive replacement of n-Al for advanced energetics with lower ESD sensitivity, better stability, and improved combustion performance.

Identifier

84987802530 (Scopus)

Publication Title

Combustion and Flame

External Full Text Location

https://doi.org/10.1016/j.combustflame.2016.08.015

e-ISSN

15562921

ISSN

00102180

First Page

179

Last Page

186

Volume

173

Grant

HDTRA1-11-1-0060

Fund Ref

Defense Threat Reduction Agency

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