A heat source model for dissimilar Al/Cu friction stir welding process based on tool torque measurement

This paper proposes a heat source model for dissimilar Al/Cu friction stir welding (FSW). First, tool torques of various welding parameters are real-time monitored and then analyzed for plunging, dwelling, welding and cooling stages of the FSW process. Second, total heat input is obtained based on the measured tool torque and is utilized to establish a combined heat source model of the four stages during Al/Cu FSW. In the model, heat distribution on the shoulder and the pin is regarded as planar and volumetric heat flux, respectively. Finally, the temperature distribution and evolution in dissimilar Al/Cu FSW are calculated by developing a numerical model, and the results are found to be in good agreement with the experimental observations. The present work avoids the complexity of determining different contact variables at the tool-workpiece interface and also provides an effective method for a quick prediction of the thermal responses during the full process of dissimilar materials FSW.