Development of Ultrasonic Welding Equipment for Refractory Metals
Abstract
The requirements established during Phase 1 for a heavy-duty ultrasonic welding system are being analyzed, and associated development problems are being resolved. High-power ceramic-transducer assemblies, power-force programming elements, and switching devices for a motor-alternator power source are being assembled and experimentally evaluated. Current information on refractory metal developments affecting the ultrasonic weldability of such material, as well as data on candidate welding tip materials, is being accumulated and studied. Information, derived from the current literature and other sources, is presented for: (Cb(D-31), Mo-0.5Ti, Rene 41, and tungsten. Composition and physical properties are summarized for five candidate welding tip materials: Astroloy, Udimet 700, Udimet 500, NIMONIC 115, and Nicrotung. These materials, except for Nicrotung, are all nickel alloys of similar composition. The design of a tension-shell transducer unit with increased power-handling capacity was evolved, and an acoustic absorber for measuring the transducer conversion efficiency calorimetrically was assembled and utilized. An aluminum-bronze coupler element was fabricated, installed in a 2-kilowatt ultrasonic welder, and successfully operated to the limited power capacity of this welder. A portion of the time-base circuitry for the power-force programming system was evaluated. The results met the tentative design requirements of a 0.002-second maximum time delay. The performance of a 7.5-kilowatt motor-alternator and the stability of the critical frequency-controlling elements demonstrated the practicality of powering ultrasonic spot-welding equipment with such a rotating machine power source. Solid-state switching devices with a response time of 8 to 12 microseconds will probably be used if the projected 25-kilowatt ultrasonic welding machine is powered by a motor alternator. Design of the primary welding machine structure was initiated.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1962
- Accession Number
- AD0277660
Entities
People
- Nicholas Marpois