Cast cured, high energy, composite materials are used across the Department of Defense (DoD) in rocket motors, explosives, and pyrotechnic devices. The current state of the art for producing these materials involves mixing the components using a bowl and impeller then moving that mixture into the vessel intended to hold it. Transferring the material and cleaning the mixing apparatus both produce waste material, require the use of cleaning solvents, and expose workers to hazardous conditions.
Dr. Andrew Nelson, and his team from the Naval Air Warfare Center – Weapons Division, addressed this problem by demonstrating a new process called Resonant Acoustic Mixing (RAM) which eliminates mixing and transferring the mixture separately by mixing energetic materials directly inside the final vessel. Low-frequency, high-intensity vibrations are used in place of impeller blades to process the composite formulations and produce energetic materials that meet military specifications. Mixing the material in situ is expected to reduce costs and increase adaptability and efficiency of production across applicable energetic materials.
In this project, Dr. Nelson and his team successfully demonstrated the RAM technology by manufacturing warheads made from plastic bonded explosive formulations in situ using both single and multi-warhead mixing fixtures. The warheads produced were tested extensively to ensure they match the safety and performance of materials produced using the conventional process.
RAM is considered a green processing technology which is useful to DoD because it has high cost-saving potential and a positive impact on the environment. RAM technology is expected to reduce supply and waste disposal costs and reduce hazardous waste risk by cutting down on handling requirements. For their efforts in the demonstration of Green Processing of Energetic Materials Using Resonant Acoustic Mixing Technology, Dr. Andrew Nelson and his team have been awarded the 2018 ESTCP Project of the Year from the Weapons Systems and Platforms Program Area.