Thermal-Fluid Coupling Numerical Simulation of Axial Ultrasonic Vibration Friction Stir Welding

In this study, a mathematical model of axial ultrasonic vibration enhanced friction stir welding is developed to predict the effect of ultrasonic vibration during friction stir welding of aluminum alloys 6061. The research focuses on the effect of with/without axial ultrasonic vibration in friction stir welding by the temperature distribution and material flow characteristics. Results indicate that the addition of axial ultrasonic vibration can reduce the heat generation rate and the temperature of contact surface between the rotating tool tip and the workpiece during the welding process, and improve the flow rate of the plastic metal material near the rotating tool tip. Under the same process parameters, when the vibration frequency is constant, as the vibration amplitude increases, the peak temperature of the welding decreases gradually, and the flow rate of the plastic metal material gradually increases