Control and Modeling of Friction Stir Welding
- The REACH lab is collaborating with manufacturing faculty to investigate the use of feedback control to improve the quality of friction stir welded materials.
- Michael Zinn – Department of Mechanical Engineering, University of Wisconsin-Madison
- Frank Pfefferkorn – Department of Mechanical Engineering, University of Wisconsin-Madison
- Woongjo Choi – Department of Mechanical Engineering, University of Wisconsin-Madison
- Bandar Aloyaydi – Department of Mechanical Engineering, University of Wisconsin-Madison
- National Science Foundation (CMMI)
- Office of Naval Research (ONR – STTR)
- Wisconsin Innovation & Economic Development Research Program (IEDR)
Friction stir welding was invented at The Welding Institute (TWI) in the UK in 1991. This relatively new, solid-state joining process differentiates itself from many other welding processes by not melting the workpiece. As a result, the joining process generates excellent joint properties, is energy efficient, environment friendly, and versatile. The basic concept of FSW can be described as follows: a non-consumable rotating FSW tool with a specially designed shoulder and probe is pressed against the base metal surface, while a vertical downward force is applied. Due to friction between the rotating tool and the workpiece and plastic deformation of the workpiece, the temperature in the weld zone increases. The generated heat is usually not sufficient to melt the material, however, the workpiece is softened in the area around the probe and the deformation resistance (i.e., yield strength) of the base material decreases. The tool is traversed along the weld interface to mix the joining members in a forging action along the joining line to create a weld in the solid state. Friction stir welding results in intense plastic deformation and temperature increase in the weld zone, which leads to a significant microstructural evolution without typically causing phase changes.
While FSW is superior to other welding processes, such as gas-arc welding, significant challenges remain in regards to robust process control, weld defect detection, and field use (for repair or large structure manufacturing). Our research has focused on solving these problems, primarily through the application of robotics and closed-loop process control and monitoring.
- Congratulations: WoongJo (Jo) Choi has successfully defended his Ph.D. Dissertation June 14th, 2018: Please join me in congratulating Jo on the successful defense of his Ph.D. dissertation: “In-Process Monitoring and Data Analysis for Quality Control of Friction Stir Welding”. A hearty thanks to Jo for all his hard work!
- M.S. Thesis and Defense – Conley, A: The Design of a Wireless System for Closed-Loop Control and High-Resolution Data Acquisition of the Friction Stir Welding Process May 2nd, 2018: Andrew Conley, an M.S. student in the UW Robotics Engineering, Applied Controls, and Haptics Lab (REACH Lab) has successfully completed his M.S. Thesis Defense. Andrew’s research focused on the development of a high data-rate, low latency wireless temperature measurement system to facilitate the control and experimental investigation of Friction Stir Welding. Please ...
- NAMRC 45: The Effects of Welding Parameters and Backing Plate Diffusivity on Energy Consumption in Friction Stir Welding
The objective of this work is to investigate the effects of welding parameter variation and backing plate diffusivity on energy consumption in friction stir welding (FSW). FSW is a solid-state welding process, where joints are created below the solidus temperature of the workpiece. As a result, FSW is known for being energy efficient and environmentally ...
- Preliminary Examination – Bandar Aloyaydi has successfully completed his Ph.D. Preliminary Examination presentation Feb 24, 2017: Bandar Aloyaydi, a Ph.D. student in the UW Robotics Engineering, Applied Controls, and Haptics Lab (REACH Lab) has successfully completed his Ph.D. Preliminary exam. Bandar’s research has focused on the investigation of force and power transients during Friction Stir Welding. Please join us in congratulating Bandar on his achievement.