Monitoring and control in friction stir welding

Abstract

Friction stir welding (FSW) is a relatively new (1991) solid-state welding technique where the material is joined via mechanical stirring. In this dissertation, methods for the automatic monitoring and control of FSW are presented. Monitoring techniques include gap fit-up detection, tool misalignment detection and estimation, and tool wear detection. Additionally, a technology which accomplishes automatic joint-line tracking for FSW (through-the-tool tracking) is presented. Joint-tracking has shown to be very useful in other welding technologies and will likely improve the flexibility and applicability of FSW.