Environmentally Sustainable Gasless Delay Compositions for Fuzes

Dr. Jay Poret | U.S. Army ARDEC

WP-2518

Objective

Pyrotechnic delay compositions are used by the U.S. Military in a variety of munitions, especially in fuzes for hand grenades. Thousands of these items are used on military training ranges in the U.S. each year, creating a significant risk of range contamination and subsequent training disruptions. The use of toxic materials in these delay compositions increases the costs of complying with environment, safety, and occupational health (ESOH) regulations in manufacturing. The replacement of toxic delay compositions with benign alternatives would provide operational and cost advantages in addition to environmental benefits and is of importance to the Department of Defense.

This project seeks to develop versatile gasless environmentally benign replacement delay compositions for use in fuzes, particularly M201A1, M208, M213, and M228. Newly-developed compositions will be compatible with existing fuze hardware and primers, will burn at rates suitable for achieving the times specified for each particular fuze, and will reliably ignite fuze output charges. Operation at extreme cold and hot temperatures will be verified in fully assembled fuze hardware. Composition sensitivity and specific processing requirements for manufacturing will be determined. Throughout the project, candidate materials, compositions, and combustion products will be evaluated according to ASTM Standard E2552-08 to ensure minimal health and environmental impact.

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Technical Approach

The approach will elucidate the chemical and physical properties required to develop new versatile environmentally benign gasless delay compositions by addressing four specific areas: (1) extending the previously developed compositions in fuze hardware, (2) determining the mechanisms that drive ignition, propagation, and reliability of the traditional systems, (3) using that understanding to develop replacement compositions with alternative environmentally benign oxidizers (e.g. oxides), and (4) for the first time developing compositions based on ceramic boride and silicide fuels. In the first year, the burning rates of initial candidates will be assessed in fully assembled M201A1 fuzes, providing a baseline. The researchers will use in-depth thermochemical modeling coupled with fundamental characterization of traditional systems to drive the science-based selection of alternative environmentally benign compositions. Detailed burning rate studies as a function of consolidated density, diameter, housing material, particle size, morphology and distribution, the role of pressure, and aging as well as safety evaluation of these compositions will be conducted in years two and three. ESOH assessments, including in vitro toxicological testing of down-selected compositions will be conducted by the U.S. Army Public Health Command in the first year.

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Benefits

This research will advance the state of the art in pyrotechnic delays while providing a well-characterized and proven replacement for use in multiple U.S. Military fuze items. Characterization of the traditional chromate- and perchlorate-based systems in the first year will elucidate the chemical and physical properties required for any versatile gasless delay composition. These studies are needed to provide a scientific basis for the rational design of optimized replacement compositions. The work will advance the pyrotechnic state of the art, in part by exploring new ceramic fuels. The full potential of these commercially available materials has not been realized in the field of energetics. The resulting environmentally benign compositions will be suitable candidates for use in multiple fuzes. Once implemented, the hundreds of thousands of U.S. Military fuze items manufactured and used each year will no longer pose an environmental or regulatory hazard. Importantly, it will be possible to manufacture the new compositions inexpensively using current production methods and equipment. (Anticipated Project Completion - 2018)

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Points of Contact

Principal Investigator

Dr. Jay C. Poret

U.S. Army ARDEC

Phone: 973-724-3035

Fax: 973-724-3035

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