Mechanically Induced Ignition of Thermite Nanocomposite Powders

Mechanically Induced Ignition of Thermite Nanocomposite Powders

R. A. Williams¹ and E. L. Dreizin¹

¹Department of Chemical, Biological, and Pharmaceutical Engineering, New Jersey Institute of Technology,

Newark, New Jersey 07102, USA

This paper examines the mechanically induced ignition of nanocomposite thermite powders prepared by Arrested Reactive Milling.  Powders are placed on a glass substrate as a thin layer and covered by an aluminum foil.  Another powder, typically a nanocomposite thermite with gas-generating oxidizer, such as 2.35Al+Bi₂O₃ is placed on top of the aluminum foil and is ignited by an electrostatic discharge (ESD).  As a result of its ignition, a pressure wave is generated that compresses the powder placed beneath the foil and causes its ignition.  The experimental diagnostics include optical sensors, high-speed video, in addition to real time monitoring of the ESD current.  In separate reference experiments, a pressure sensor is placed between the foil and glass, instead of the powders being ignited.  Ignition delays and pressure pulse delays are correlated with each other.  Effects of the powder layer thickness, type of powder used, and discharge settings (voltage, capacitance) are also explored.