General Thermomechanical Model of FSW based on a Characteristic Temperature for Deformation and Heat Transfer

This research addresses the limitations of friction stir welding (FSW) in predicting the ideal temperature required to optimize its results, as well as how welding parameters and material properties influence this prediction. The study introduces a comprehensive model that combines heat transfer and plastic deformation in FSW, incorporating factors such as the temperature near the welding pin and principles from fluid mechanics. By utilizing scaling and calibration methods based on existing data, the model improves accuracy and focuses on critical FSW conditions. A unique geometric approach is employed to calculate the temperature at the shear layer's edge, considering deformation rate, stress, and temperature. The resulting model provides equations for key parameters applicable to all metals and undergoes extensive validation. It serves as a valuable tool for predicting temperature and torque, enabling the determination of optimal procedure variables and the development of comprehensive process limit maps. This research makes a valuable contribution to the progress of welding technologies, which find applications in various industries including rocket manufacturing and others, by addressing the predictive challenges in FSW.