Analysis of 3D flow in friction stir welding process

This paper reported the 3D flow of material in the friction stir welding process by using finite element method. Results indicate that there exists a relation between the equivalent plastic strain distributions and the microstructure zones. The flow of material is very weak behind the pin on the retreating side and the flow is faster in front of the pin on the retreating side. The material in front of the pin is forced to move upwards, then the upward material rotates with the pin and the material behind the pin is forced to move downwards to fill the vacant space due to translational movement of the rotational tool, which makes friction stir welding process continuous successfully.