- Reactive material
In military, reactive materials (RM) are new class of materials currently being investigated by the
Office of Naval Researchand others as a mean to increase the lethalityof direct-hit or fragmentation warheads. Reactive materials are usually thermite-like pyrotechnic compositions of two or more nonexplosive solid materials, which stay inert and do not react with each other until subjected to a sufficiently strong mechanical stimulus, after which they undergo fast burning or explosion with release of high amount of chemical energyin addition to their kinetic energy. Fragments or projectiles made of such materials have therefore greater damaging effect than inert ones, with expected lethality increase up to 500%.
The material classes under investigation are
thermites, intermetalliccompounds, metal-polymer mixtures (e.g. Magnesium/Teflon/Viton-like), metastable intermolecular composites (MIC), matrix materials, and hydrides. [http://books.nap.edu/openbook.php?record_id=10918&page=20] They have to be strong enough to act as structural components and be able to penetrate the target, sufficiently stable to survive handling and launch, and sufficiently unstable to reliably ignite on impact.
The mixtures under investigation include one or more finely powdered (down to
nanoparticlesize) metalloids or metals like aluminium, magnesium, zirconium, titanium, tungsten, tantalum, or hafnium, with one or more oxidizers like teflonor other fluoropolymer, pressed or sintered or bonded by other method to a compact, high-density mass. To achieve a suitable reaction rate and insensitivity to impact, friction, and electrostatic discharge, fuel particles have sizes usually between 1-250 µm. [http://www.freepatentsonline.com/20030096897.html] [http://www.patentstorm.us/patents/6962634-description.html] A standard composition is aluminium-teflon (Al-PTFE).
The RM weapons under development include an
active protection systemdefensive grenade for interception of incoming missiles or grenades and detonation of them in a safe distance, and the BattleAxe warhead that covers a wide area with RM fragments with devastating results to soft targets, while the unexploded fragments left behind having very low lethality in comparison with conventional cluster bombleftovers.
* [http://www.popularmechanics.com/technology/military_law/4219350.html Popular Mechanics: Better Bombs: Scientists develop metal that explodes on impact]
* [http://www.spaceref.com/news/viewpr.html?pid=9956 SpaceRef: Better warheads through plastic]
* [http://www.wired.com/politics/security/news/2008/05/reactive_revolutions Wired: In Next-Gen Bullets and Bombs, Even the Casing Explodes]
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