Master of Science, The Ohio State University, 2008, Welding Engineering

Ultrasonic metal welding (UMW) is a solid-state joining process in which materials are held together under moderate forces while applying localized high frequency shear vibrations, creating a true metallurgical bond. While ultrasonics have been applied extensively to joining soft materials, such as copper and aluminum, applications for joining more advanced materials are limited. UMW has generally not been considered for more advanced materials due to poor tooling life and inadequate ultrasonic power levels. In a relatively short period of time, developments in UMW equipment and potential tool materials, may allow UMW to be applied to these more advanced metals. Using commercially-available ultrasonic spot welding equipment, the ultrasonic weldability of 304 and 410 stainless steel, commercially pure and 6Al-4V titanium, and Nickel-base superalloys 625 and 718 was investigated. Tool materials developed for friction-stir weld tooling were used to develop new ultrasonic tools. Tool textures and designs were also evaluated.

Committee: Karl Graff (Advisor) Subjects: