Reactive material

In the <a href="/facts/United_States_Department_of_Defense/dWAvf7e3">U.S. military</a>, reactive materials (RM) are a new class of materials currently being investigated by the <a href="/facts/Office_of_Naval_Research/qKug0oD2">Office of Naval Research</a> and others as a means to increase the <a href="/facts/Lethality/03bCAHTD">lethality</a> of direct-hit or fragmentation <a href="/facts/Warhead/DKJ7lyqb">warheads</a>. Reactive materials are similar to <a href="/facts/Insensitive_munitions/S6Xj351q">insensitive high explosives</a>, but are usually <a href="/facts/Thermite/vIbVld9Y">thermite</a>-like <a href="/facts/Pyrotechnic_composition/C1HG3gVw">pyrotechnic compositions</a> of two or more nonexplosive solid materials, which stay inert and do not react with each other until subjected to a sufficiently strong mechanical, electrical or laser stimulus, after which they undergo fast burning or <a href="/facts/Explosion/Utp8Wv9D">explosion</a> with release of high amount of <a href="/facts/Chemical_energy/Y3VP3Ifq">chemical energy</a> in addition to their <a href="/facts/Kinetic_energy/aJRxUd4p">kinetic energy</a>. 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 <a href="/facts/Thermite/vIbVld9Y">thermites</a>, <a href="/facts/Intermetallic/nnzksayl">intermetallic</a> compounds, metal-polymer mixtures (e.g., <a href="/facts/Magnesium/teflon/viton/K0B4FVWF">magnesium/teflon/viton</a>-like), <a href="/facts/Metastable_intermolecular_composite/E1HdJwrc">metastable intermolecular composites</a> (MIC), matrix materials, and <a href="/facts/Hydride/v2rlBGMg">hydrides</a>. These materials must be strong enough to act as structural components, be sufficiently stable to survive handling and launch, to penetrate a target, and sufficiently unstable to reliably ignite on impact.
The mixtures under investigation include one or more finely powdered (down to <a href="/facts/Nanoparticle/k8kNxX4E">nanoparticle</a> size) <a href="/facts/Metalloid/uMFVXuTq">metalloids</a> or metals like <a href="/facts/Aluminium/7wmR8jYE">aluminium</a>, <a href="/facts/Magnesium/XyIhd2FG">magnesium</a>, <a href="/facts/Zirconium/y7gsoQFz">zirconium</a>, <a href="/facts/Titanium/53ArnDoy">titanium</a>, <a href="/facts/Tungsten/WYwbNDYX">tungsten</a>, <a href="/facts/Tantalum/VwaxMm33">tantalum</a>, <a href="/facts/Uranium/n2sGWBzU">uranium</a> or <a href="/facts/Hafnium/rBNnlxDS">hafnium</a>, with one or more oxidizers like <a href="/facts/Teflon/jesBNXKq">teflon</a> or other <a href="/facts/Fluoropolymer/lMxPIDGc">fluoropolymer</a>, pressed or <a href="/facts/Sintering/Y4eGLzFf">sintered</a> or bonded by other method to a compact, high-density mass. To achieve a suitable <a href="/facts/Reaction_rate/Prwvxq0y">reaction rate</a> and insensitivity to impact, friction, and <a href="/facts/Electrostatic_discharge/I55BBYfS">electrostatic discharge</a>, fuel particles have sizes usually between 1-250 μm. A standard composition is aluminium-teflon (Al-PTFE).
Metals which can form <a href="/facts/Intermetallic/nnzksayl">intermetallic</a> compounds by an <a href="/facts/Exothermic/gCuSvpa4">exothermic</a> reaction are another class of candidate materials. An example is a <a href="/facts/Laminate/o9EGJdwn">laminate</a> of thin alternating layers of <a href="/facts/Aluminum/7wmR8jYE">aluminum</a> and <a href="/facts/Nickel/KwMCHYRP">nickel</a>, commercially available as <a href="/facts/NanoFoil/9jwhd1qB">NanoFoil</a>.
The RM weapons under development include an <a href="/facts/Active_protection_system/yTLBIpna">active protection system</a> defensive grenade for intercepting incoming missiles or grenades and detonating them at a safe distance, and the BattleAxe warhead that covers a wide area with RM fragments with devastating results to <a href="/facts/Soft_target/YK8pRe5A">soft targets</a>, while the unexploded fragments left behind have very low lethality versus conventional <a href="/facts/Cluster_bomb/QpvG4eeR">cluster bomb</a> remains.
Under research are materials with high <a href="/facts/Mechanical_strength/CE77cUcB">mechanical strength</a>, high density, high <a href="/facts/Energy_density/mwBXA7bC">energy density</a>, and which can rapidly convert from a consolidated structural material to fine powder with large surface area, be dispersed and then ignited to produce a large <a href="/facts/Thermobaric_weapon/PuM9XaRD">thermobaric</a> blast.
A <a href="/facts/Palladium/AXMwDFxs">palladium</a>-clad <a href="/facts/Aluminum/7wmR8jYE">aluminum</a> wire, known under trademark Pyrofuze, is used as a <a href="/facts/Pyrotechnic_initiator/BfUDd0PM">pyrotechnic initiator</a>.
Reactive materials also have non-weapon uses. Thin layers of reactive materials, clad with a <a href="/facts/Solder/GBvJH75t">solder</a>, are used for <a href="/facts/Reactive_bonding/KQAhf3MT">reactive bonding</a>, e.g., in electronics, or for <a href="/facts/Brazing/JBgswMLw">brazing</a>, such as in <a href="/facts/Composite_armor/7ChAyoFA">composite armor</a> plates.

Reactive material open-in-new

Reactive material