Accession Number:

ADA622899

Title:

Ignition of Nanocomposite Thermites by Electric Spark and Shock Wave

Descriptive Note:

Journal article

Corporate Author:

ILLINOIS UNIV AT URBANA-CHAMPAIGN

Report Date:

2014-04-30

Pagination or Media Count:

13.0

Abstract:

Nanocomposite 8Al-MoO3 thermite particles were prepared using arrested reactive milling and ignited using two experimental techniques. In spark ignition, a monolayer of powder was placed on a conductive sub- strate and heated in air by a pulsed electrostatic discharge. In shock ignition, an individual particle was targeted by a miniature, laser-driven flyer plate accelerated to a speed in the range of 0.5--2 kms1 In both experiments, time-dependent optical emission produced by the ignited material was monitored and recorded. The heating rates achieved in the present experiments are on the order of 10exp9- -10exp11 Ksexp-1. These ignition methods result in a very fast combustion with characteristic burn times reduced by 1--3 orders of magnitude compared to the burn times measured previously for the same material ignited in the CO2 laser beam, where it was heated at a much lower rate of about 10exp6- -10exp7 Ksexp-1. Ignition delays observed in both shock and spark ignition experiments are close to each other and vary in the range of 120--200 ns. The times of characteristic rapid increase in the optical emission of the ignited particles are also close to each other for the two experiments however, these times are somewhat shorter less than one mu for the spark ignition tests compared to few mu observed for the shock initiated particles. Preliminary ideas enabling one to interpret the present results are discussed. This work establishes an approach for systematic studies of high rate ignition and respective combustion of nanocomposite reactive materials.

Subject Categories:

  • Laminates and Composite Materials
  • Ammunition and Explosives
  • Thermodynamics
  • Combustion and Ignition

Distribution Statement:

APPROVED FOR PUBLIC RELEASE