Sealing of Propellant Containers by Ultrasonic Welding, Phase III

摘要

Ultrasonic ring welding was successfully used to produce hermetic closures of propellant containers requiring formation of the welds in recessed cavities in the container bodies. The container body, Picatinny Ordnance Part No. XP-113711, was used without modification. The cover material was 0.005-inch-thick 3003-H19 aluminum alloy. After ultrasonic cleaning, the components were welded with a laboratory-type ultrasonic ring welding machine providing a power handling capacity of up to 10 kilowatts, modified to incorporate a special torsional coupling element, ring welding tip, and two-part welding anvil that provided a threaded receptacle for the container body. Representative assemblies, each filled with 65 grams of M10 propellant, were welded at 5400-watts electrical power, 1500-pounds clamping force, and 0.5-second weld time. Metallurgical evaluation indicated sound bonds, and hermetic sealing was verified by helium-leak and ethyleneglycol-submersion tests. Fifty such assemblies were delivered to Picatinny Arsenal for further evaluation. The process was considered applicable to production welding of these assemblies at rates substantially in excess of 1500 units per hour. (Author)