Solid-state Spray Forming of Thermite and Porous Aluminum for Aluminum-Water Acoustic Sources

"Development of broadband acoustic sources using an aluminum-water reaction can now be attained using a solid-state spray forming technology to consolidate aluminum powders into porous foam structures and thermite composite igniters. The Navy is currentlyseeking a non-explosive command activated broadband acoustic source for multi-static anti-submarine warfare. Key attributes for attaining a stoichiometric yield of an aluminum-water explosion depend on ignition-threshold temperature, heat rates, particlesize, seawater infiltration, and sustaining transportation of seawater steam into the aluminum matrix during the confined reaction. Thermite composite igniters are the only low power (electrical) candidates for providing a sufficiently uniform heat impulsewith a threshold temperature >1170 K for the confined mixture. The object of the Phase I research is to investigate parametric configurations for an aluminum-water acoustic source consolidated with aluminum powders using the solid-state spray formingtechnology. The intended application is a low cost and safe replacement for the high-energy explosive capsules currently used on the SSQ-110 sonobuoys. The object of the Phase I "fast track" option is to begin initial Phase II activities with detaileddesign of housings, deployment mechanisms, the ignition and control systems necessary to deploy and direct a broadband acoustic pulse. Development of a high-energy underwater acoustic source