Monitoring of the friction stir welding process to describe parameter effects on joint quality

With the industrial use of FSW growing steadily, non-destructive testing methods that can detect the impending formation of flaws during welding must be developed. The present work accomplished two goals. First, the distribution of oxide fragments within aluminium welds could be correlated with certain welding process variables. Consequently, an approach was suggested to prevent the conglomeration of oxide fragments in the weld by reducing the surface roughness of the abutted edges. Second, welding forces can be used to predict the formation of elongated cavities inside the weld. This project showed that by monitoring the welding forces, the ability to change the welding variables in real time could prevent the formation of flaws in friction stir welds.