Development of a Real-Time Wireless Tool Temperature Measurement System for Friction Stir Welding Monitoring

Friction stir welding is a solid-state welding technique that softens and joins materials using frictional heat generated at the interface between the rotating tool and the workpiece. This frictional heat is influenced by various parameters, such as tool geometry, rotational speed, transverse speed, and plunge depth. To optimize weld quality, it is essential to study the relationship between frictional heat and welding process parameters. Conventional methods, such as measuring the workpiece temperature, make it difficult to monitor and control the process in practical FSW applications because the process temperature along the welding path is challenging to measure. To solve this, this study proposes directly measuring FSW tool temperature. During FSW, a wireless temperature measurement system is devised to capture tool temperature in real time. Transient tool temperature profiles were measured under various FSW conditions, and the stabilized tool temperature showed a strong correlation with the tool rotation speed.