Nanoenergetic Materials (nEMs) in Conventional Ammunition

Nanoenergetic Materials (nEMs) in Conventional Ammunition

By Rear Admiral Dr. S. Kulshrestha (Retd.)
Indian Navy

Nanoenergetic Materials (nEMs) in Conventional Ammunition

Nanotechnology “could completely change the face of weaponry,” - Andy Oppenheimer, Jane’s Information Group[1]

On 11 September 2007, Russians tested Father of All Bombs (FOAB), an Aviation Thermobaric Bomb of Increased Power (ATBIP). It was said to be the most powerful conventional bomb in the world, with a 7-Ton explosive mixture resulting in a devastating effect equivalent to 44 tons of TNT[2]. It was hinted that the FOAB contained a liquid fuel, such as ethylene oxide, mixed with energetic nano-aluminum powder, which was dispersed by a high explosive booster. Some reports speculated that the liquid fuel was purified using nano-filters. What caught the imagination of defense experts was the fact that the Russian FOAB had less fuel than the similar US device Mother of All Bombs (MOAB), the GBU-43/B Massive Ordnance Air Blast bomb, but was four times more powerful. It was also probably the first time that the nonprofessional learned of the lethal uses of nanotechnology. Not much information is available through open sources about the developments involving nanotechnology in explosives, much of it has to be gleaned from research papers and patents (for e.g. Patents like US6955732 - Advanced thermobaric explosive compositions and WO2013119191A1 - Composition for a fuel and air explosion).

Since 2004, ‘Combat Safe Insensitive Munitions’ concept has shifted the focus of safety from a pure materials approach to making marine explosives insensitive to a platform based approach based upon mechanics to increase insensitivity[3]. US Navy has been at the forefront of R&D into new energetic materials since a long time and it is opined that nanotechnology-enabled energetic materials would form the backbone of the future defense systems. Timely induction of nano-enabled energetic systems with controlled energy release is the focus of current research at institutes like the U.S. Naval Academy, Naval Surface Warfare Center, and the University of Maryland.

In simple terms, Nanoenergetic materials (nEMs) perform better than conventional materials because of a much larger surface area, which increases the speed of reaction and larger energy release in much shorter time. Addition of Superthermites[4] (nano-aluminum based) has shown instantaneous increase in explosive power of existing compositions[5]. Further, use of nano-sized materials in explosives has significantly increased safety and insensitivity by as much as over 30% without affecting reactivity. It is predicted that nEMs would provide the same explosive power at mass up to two orders of magnitude less than the current explosive systems[6].

In the rocket, propellants nEMs have shown similar capabilities at Los Almos National Laboratories with nitrogen-energized nEMs[7]. In addition, incorporation of more than one burning rate in rocket propellants has given rise to novel design options by creating grains with continuously varying properties along the length as well as across the radius of the grain in Functionally Graded Materials (FGM).

While nanosizing of high explosives leads to increase their explosive power[8] and decreasing their sensitivity to external forces[9], it also decreases their thermal stability. The shelf life of such explosives could, therefore, stand reduced, however, some patents reveal that this issue has also been resolved technically (e.g. patent US20120227613 Thermal enhanced blast warhead). In India, the work on explosives and propellants is being undertaken at HEMRL, a DRDO laboratory, and it is understood that the research in nEMs is progressing satisfactorily.


Projections


Nanotechnology is permeating in all fields of design & manufacturing of weapons and ammunition. It is bringing unprecedented precision in weapon systems, robustness in triggering mechanisms and opening new frontiers in propellant and pyrotechnic functioning. In addition to explosive and propellants, nanomaterials have ushered in innovative improvements in many characteristics of ammunition such as guidance, penetration capacity, embedded sensors for monitoring condition, embedded antennae for guidance and so on.

It can be envisaged that nEMs would replace the conventional explosives in the next decade. This would provide existing conventional weapons with explosive powers higher in magnitude by a factor of two and enhance the safety of external stimulation by at least 30%. In simple terms, a missile warhead having an explosive content of 200 kg of TNT equivalent would have an explosive power of 20,000 kg of TNT equivalent when substituted with nEMs material of same weight of 200 kg!

This advancement could displace Tactical nukes from the battlefield.

What can also be foreseen is the mushrooming of new classes of extremely precise and lethal small/micro weapon systems, which could be scaled down by at least second order of magnitude from the current systems- thus creating space for the likely paradigm shift from bigger & larger to the smaller & numerous holdings of weapons. This, in turn, would herald the era of Swarm Warfare.

About the Author:

RADM Dr. S. Kulshrestha (Retd.), INDIAN NAVY, holds expertise in quality assurance of naval armament and ammunition. He is an alumnus of the NDC and a Ph.D. from Jawaharlal Nehru University, New Delhi. He superannuated from the post of Director-General, Naval Armament Inspection in 2011. He is unaffiliated and writes in defense journals on issues related to Armament technology and indigenization.

Publication Details:

This article was originally published in a blog maintained by Centre for Land Warfare Studies, New Delhi and it is republished on IndraStra with the permission from Author and the Original Publisher. All Rights Reserved by Centre for Land Warfare Studies.

References:

[1] Gartner, John. “Military Reloads with Nanotech.” Technology Review, an MIT Enterprise, January 21, 2005. http://www.technologyreview.com/computing/14105/page1/

[2] http://news.bbc.co.uk/2/hi/europe/6990815.stm

[3] Insensitive munitions:

Improve the safety and survivability for Armed Forces and civilians in urban areas or near combat zones because they can safely be stored at closer distances. Reduce the vulnerability of platforms and resources against unintended or hostile aggression, violent reactions with blast overpressure and fragmentation damages are under control. Maximize the storage capabilities and improve flexibility logistics: IM can safely be carried by land/sea/air; storage platforms can be closer together and are key to Inter-Operability between the Armed Forces.

[4] Nano-Thermite or Super-Thermite is a metastable intermolecular composite (MICs) containing an oxidizer and a reducing agent, which are intimately mixed on the nanometer scale. This dramatically increases the reactivity relative to micrometer -sized powder thermite. MICs, including nano-thermitic materials, are a type of reactive materials investigated for military use, as well as for general applications involving propellants, explosives, and pyrotechnics.

[5] Gartner, John. “Military Reloads with Nanotech.” Technology Review, an MIT Enterprise, January 21, 2005. http://www.technologyreview.com/computing/14105/page1/

[6] Yang, Guangcheng, Fude Nie, Jinshan Li, Qiuxia Guo, and Zhiqiang Qiao. “Preparation and Characterization of Nano-NTO Explosive.” Journal of Energetic Materials, 25, 2007. 

[7] Tappan, B.C., S.F. Son, and D.S. Moore. “Nano-Aluminum Reaction with Nitrogen in the Burn Front of Oxygen-Free Energetic Materials.” Shock Compression of Condensed Matter, American Institute of Physics, 2005

[8] Kaili Zhang, Carole Rossi, and G.A. Ardila Rodriguez. “Development of a Nano-Al/CuO Based Energetic Material on Silicon Substrate.” Applied Physics Letters No. 91, 14 September 2007.

[9] Guangcheng Yang, Fude Nie, Jinshan Li, Qiuxia Guo, and Zhiqiang Qiao. “Preparation and Characterization of Nano-NTO Explosive.” Journal of Energetic Materials, 25, 2007.
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