Rapid initiation of reactions in Al/Ni multilayers with nanoscale layering

Christopher J. Morris*, Brian Mary, Eugene Zakar, Sara Barron, Greg Fritz, Omar Knio, Timothy P. Weihs, Ralph Hodgin, Paul Wilkins, Chadd May

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

64 Scopus citations

Abstract

Research into nanoenergetic materials is enabling new capabilities for controlling exothermic reaction rates and energy output, as well as new methods for integrating these materials with conventional electronics fabrication techniques. Many reactions produce primarily heat, and in some cases it is desirable to increase the rate of heat release beyond what is typically observed. Here we investigate the Al-Ni intermetallic reaction, which normally propagates across films or foils at rates lower than 10 m/s. However, models and experiments indicate that local heating rates can be very high (107 K/s), and uniform heating of such a multilayer film can lead to a rapid, thermally explosive type of reaction. With the hopes of using a device to transduce electrical energy to kinetic energy of a flyer plate in the timescale of 100's of nanoseconds, we have incorporated a Ni/Al nanolayer film that locally heats upon application of a large electrical current. We observed flyer plate velocities in the 2-6 km/s range, corresponding to 4-36 kJ/g in terms of specific kinetic energy. Several samples containing Ni/Al films with different bilayer thicknesses were tested, and many produced additional kinetic energy in the 1.1-2.3 kJ/g range, as would be expected from the Ni-Al intermetallic reaction. These results provide evidence that nanoscale Ni/Al layers reacted in the timescale necessary to contribute to device output.

Original languageEnglish (US)
Pages (from-to)84-89
Number of pages6
JournalJournal of Physics and Chemistry of Solids
Volume71
Issue number2
DOIs
StatePublished - Feb 1 2010

Keywords

  • A. Intermetallic compounds
  • A. Thin films
  • B. Plasma deposition
  • Multilayers

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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