Premium
Dynamical Effects of the Oxide Layer in Aluminum Nanoenergetic Materials
Author(s) -
Wang Shufeng,
Yang Yanqiang,
Yu Hyunung,
Dlott Dana D.
Publication year - 2005
Publication title -
propellants, explosives, pyrotechnics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.56
H-Index - 65
eISSN - 1521-4087
pISSN - 0721-3115
DOI - 10.1002/prep.200400097
Subject(s) - oxide , materials science , detonation , picosecond , layer (electronics) , microheater , aluminium , shock wave , nanosecond , optics , laser , composite material , explosive material , chemistry , metallurgy , fabrication , medicine , physics , alternative medicine , organic chemistry , pathology , engineering , aerospace engineering
Abstract Dynamical effects of the aluminum nanopowder oxide layer are investigated in nanoenergetic materials consisting of nitrocellulose (NC) oxidizer containing embedded ~ 60 nm diameter Al having thinner (2.5 nm) or thicker (6 nm) oxide layers. Following laser flash‐heating, a hot spot is formed near each Al particle. The mean distance of reaction propagation d rxn from the hot spot through the nitrocellulose is determined with ~100 nm resolution. With 100 ps pulses a shock propagation mechanism is dominant, and with 10–25 ns pulses reaction a thermal explosion mechanism is dominant. When higher energy picosecond pulses are used, d rxn is observed to be significantly increased with thicker oxide layers, but using nanosecond pulses d rxn is slightly decreased with thicker oxide layers. This oxide layer enhancement of d rxn with picosecond pulses is attributed to the thicker oxide layer confining the hot Al for several tens of picoseconds, resulting in a larger shock wave. This work supports the view of the oxide layer as deadweight for slower heating rate processes such as combustion, but it suggests a thicker oxide layer may be of some benefit for extremely high heating rate processes involved in detonation or high speed deflagration of nanoenergetic materials.